News & Pointers: S-100, CP/M and related sites

I checked for dead links again, Dec 28 2021 - our *twenty-third* year of providing S-100 on the Web. But Web-search is more likely to find what's new; but what's old may be found here. - Herb

About this Web page, and me

I'm Herb Johnson, in New Jersey USA. For decades in the 1980's and 90's, I provided some support services for old S-100 (IMSAI, Altair, Compupro, etc.) computers and also floppy disk drives - I still do that today. In the 2000's, I also accumulated a lot of information about CP/M, an early operating system for 1970's and 80's computers - mostly that's done. Since the late 2000's' I've been working on general "vintage computers" of the 1970's and a bit earlier, to encourage what I call "repair, restoration and preservation". Links are immediately below and can also be found on my domain Home Page.

This Web page is mostly from my 80's and 90's work, as a list of useful Web links to other sites with S-100, 8080 & Z80, and CP/M related information and interests. There is also some references to Digital Research (DRI) CP/M products, as DRI was the creator of CP/M which was the operating system of many S-100 systems.

My list of Web pointers here are ordered by date of entry, most recent at the top. Web links are validated occasionally, with notes accordingly. So this page is also an archive of "lost" resources; let me know if you find any "dead links". I add pointers from time to time. If I point to your site, please consider pointing to mine. Any corrections or additions would be appreciated.

My major Web pages

My home page is the entry to several area of my Web domain. This includes resources for repair and restoration of these old computers; SALES of other kinds of vintage computers; and other activities I've engaged in.

Entry into my Web pages on repair, restoration and preservation efforts by myself and others, on computers of the 1970's and earlier.

I have a lot of information on CP/M and Digital Research on my DRI Web page section. Also see my "how to CP/M" Web page..

For more information on what S-100 stuff and information I have available, check my S-100 Stuff Home page. I have a list of S-100 frequent questions also. There's links to pages discussing repairs and designs of S-100 systems; pages on every brand of S-100 computer. Also pages on test equipment I make available, and other items I sell.

For instance, I have a few Intel Multibus and STDbus Web pages with these items for sale. Multibus and STDbus were commercial alternatives to the S-100 bus. Intel 8080 and Z80 were very popular with all three bus architectures. The page also refers to some Intel development history around the 8080 and Multibus era. Of course Dr Gary Kildall worked for Intel and developed some of their early 8008 and 8080 software products - and later he developed CP/M.

Herb Johnson
New Jersey, USA
My email address is listed on this page

Index of links

S-100 related software

  • Digital Research and CP/M history through today
  • CP/M boot disks
  • CP/M, S-100 Internet-based discussions
  • Intel, ISIS and Multibus-era links
  • CP/M disk conversion: 22DISK and Sydex
  • Pascal P-system, UCSD Pascal, Modula-2, related efforts
  • SIG/M, CPMUG, Walnut Creek CP/M, Simtel, Oakland archives
  • Udo Munk's Z80PACK and

    S-100 at 35+ years

  • Obituaries
  • What is S-100?

    past and recent hardware activities

  • Who has S-100 systems?
  • My S-100 home page - I'm certainly active!
  • current Z80-class activities
  • GIDE: IDE drive for Z80
  • microSD card product supportable in CP/M

    Pointers to S-100, CP/M and Related Sites

  • 2021
  • 2015
  • 2014
  • 2013
  • 2012
  • 2011
  • 2010
  • 2009
  • 2008
  • 2007
  • 2006
  • 2005
  • 2004
  • 2003
  • 2002
  • 2001 and earlier

    S-100 related software

    Digital Research and CP/M: links and status

    My DRI related material is on my Digital Research CP/M Web pages. Any news directly related to Digital Research's old products would be on that page or pages linked from it. I have written an extensiveearly history of the development of CP/M (with references) and the first CP/M-supporting floppy disk hardware products. "Unix vs. CP/M" is discussed there also. Also see my "how to CP/M" Web page.. Much of the history of 1970's microcomputing has become "lost history" as modern reportage repeatedly asserts that the IBM PC "started" personal computing. These pages of mine attempt to correct that error with FACTS. - Herb Johnson

    2014 update The IEEE and the Computer History Museum has honored Dr. Gary Kildall with an award and recognition of his work as "an important foundation for the personal computer revolution." I discuss this and reference the award elsewhere on this Web site.

    CP/M boot disks

    Moved to my support Web page for "how to CP/M"

    CP/M, S-100 related Web-based discussions

    Ther have been Internet-based discussion venues on the Web for CP/M and S-100 for decades. First were the Usenet newsgroups, these preceeded "the Web", and are available as "news" services on some Web sites and from your Internet access provider in most cases. The primary Usenet CP/M newsgroup was comp.os.cpm, detailed below. There are other Usenet newsgroups which include discussions of CP/M or CP/M-era computers: alt.folklore.computers is very active; various newsgroups devoted to particular brands of computers, often called comp.sys.[brand name], may discuss CP/M if it runs on the named systems - "C64" is one example.

    In the 21st century super-providers like Google and Yahoo! sponsor discussion groups of some size, which include CP/M or for brands and models of "vintage" computers which ran CP/M and other Digital Research operating systems. Also, there's many private Web sites which have their own email discussion groups. Web searches for "groups" will find these, they come and go over the years. Some of them will be in my WEb links below. You will likely find Web archives for "listsrvs" - private but open email lists Also look at the Web sites in my list of current Z80-class activities as most of them have email discussion groups associated with them.

    Caution: UNMODERATED on-line discussion groups may have a few hostile persons on them. Before you decide to "join" a discussion group, look at their archive of messages, note how "active" they are, and the "feel" of the group. Some persons in these groups can be rude to people who are new and who appear not to know a lot. They may dominate the group. If someone responds in a hostile or smug fashion to your post or others, before responding check their prior posting history by searching that group's message archive. You'll likely uncover a "troll" - see this description of trolls - and I suggest you avoid responding. Unfortunately in the 21 century, civility has declined on the Internet.

    comp.os.cpm is a decades-old Usenet newsgroup for discussions about CP/M and the classic hardware it ran on; as well as discussions about new and software hardware that can support CP/M and related operating systems. In recent years, activity in comp.os.cpm (like most Usenet groups) is declining, and it has some hostile persons (see notes above). But it has value as an archive of former and present activities, answers to questions, and Web links.

    Intel, ISIS, PL/M and Multibus-era links

    Multibus and STDbus were commercial alternatives to the S-100 bus. Intel 8080 and Z80 were very popular with all three busses. For 21st century interest in Multibus, see my Multibus activity Web page. I also have some Multibus, STDbus and VMEbus computer cards for sale: check this linked page for details.

    Udo Munk's Z80PACK and

    Moved to my "how to CP/M" Web page. It's a collection of Unix (now Linux) based tools for Z80 and classic CP/M development, by Udo Munk and his colleagues.

    SIG/M, CPMUG, Walnut Creek CP/M, Simtel, Oakland & other archives

    Starting in the late 1970's, two early archives of CP/M software were created by the CP/M User's Group (CPMUG) of New York City, NY and SIG/M of New Jersey. They distributed CP/M software on 8-inch diskettes through the 1980's. There is some overlap between their contents. Their archives by name found their way to Oakland's and other on-line and CD-ROM archives. Some early work of CPMUG appears on my in my history of Digital Research and CP/M.

    CP/M-based computer companies often offered their own CP/M program distributions on diskettes. Those companies included Osborne, Kaypro, Ithaca Audio/Intersystems, and others. There are Web links on this Web page for some of those archives. Some of those archives also found their way to general on-line or CD-ROM archives of programs; and some of these archives are on the Web by their original distributors.

    In the 1990's Oakland University, in Rochester, Michigan USA archived CP/M files online in their OAK CP/M archive at That archive site no longer exists as of about year 2003, when it was taken down for economic reasons. After a Jan 2006 discussion of the Oakland archives in comp.os.cpm, I was contacted by Fritz Chwolka who told me: "A backup of [the Oakland CP/M archive] is at and I have a copy at; and a lot of other interesting [items elsewhere] [at that site]." He later noted that a description of Oakland's OAK archive exists at the Web archive project site; but in 2008 only a few Okaland Web pages were available there. Fritz also offered links to related but non-CP/M archives: hobbes for OS/2 and (Simtel) for msdos. There is also an archive to a copy here at a Z80 archive mirror Web site.

    A related archive of CP/M files was the "Simtel20" or "Simtel" archives. It was started by Keith Petersen in 1979 as a CP/M archive at MIT (University in Boston) on the ArpaNet, and later was hosted on the Internet at a military base as the "SIMTEL20" archive of software for many operating systsems. "SIMTEL" was later sold to a commercial company. As of 2008 Simtel had a Web site at and an FTP site However in 2008 they didn't have any CP/M archives, only MS-DOS and later archives, as far as I can tell. (History from the wikipedia entry for "simtel" as of 2008.) By 2013 the and sites responded with automated "not found" pages.

    From Sept 2004 to 2006, I offered a copy of the Walnut Creek CP/M CD-ROM. A short description of it is that it's a noncommerical subset of the CP/M files archived by Oakland University (in Washington state) in their "OAK CP/M" online archive. Since 2006, it's been available from a number of CP/M file archive Web sites. The Web site has the content directly online as of early 2008. A Web search today will likely find it and other archives.

    As of 2010, all of these old archives are available online at multiple sites which support CP/M, or Z80, or specific vintage computers; or modern redesigns of those computers. Check sites discussed on this Web page, or Web search for these sites.

    S-100 & CP/M related news

    In 2014 the IEEE and the Computer History Museum honored Dr. Gary Kildall with an award and recognition of his work as "an important foundation for the personal computer revolution." I discuss this and reference the award here and elsewhere on this Web site.

    S-100 at almost four decades

    The S-100 computer backplane bus was announced with the MITS Altair 8800 computer in Jan 1975 as "the Altair bus". It was used in various versions by hundreds of computer manufacturers, and became an IEEE standard like Multibus, VME, etc. Read this document about the S-100 bus. Then look at some of the info on my S-100 home page and go from there.

    Thirty five plus years later, it's still of interest, S-100 cards are sold daily on the Web. Vector Electronics still offers S-100 prototype boards in 2009. In comp.os.cpm in early May 2009, Andrew Lynch announced a proposed "new" S-100 six-slot motherboard, with termination very very similar to the Compupro design, and his own prototype boards, as part of his N8VEM Z80 Eurocard-bus computer project. In 2010, John Monahan's site also offers new S-100 blank boards. The N8VEM project "migrated" to Follow the links for details.


    Claude Kagan, an engineer who supported personal computing in its early years of the 1960's and 70's, died in April 2012 at 88 years old, while still active in that work. A personal colleague and friend of mine, he co-authored a 1973 paper in a major computing journal which predicted many features of a home personal computer, when established wisdom was skeptical. He personally mentored a generation of computer developers of note. He and they supported a derivative of an early micro and mini-computer programming language. He worked with S-100 and CP/M developers and systems, and so I reference him here accordingly.

    Dr. Ed Roberts was the cofounder of MITS in 1969, and the designer of the MITS Altair 8800 computer first sold by MITS in 1975. Ed Roberts died April 1 2010; some tributes to him and links to obituaries are on this linked Web page.

    Barry Watzman, a Heath computer manager, developer and supporter, died in May 2010. Read this Web page for details and some tributes.

    current Z80-class activities

    In the early 2000's, a number of individuals produced Z80-type systems as small projects. Some have groups of people associated in various ways. They produce small runs of boards, some provide parts or assemblies. A Google search or ebay search may find them. Also note there are old blank-boards or unbuilt kits available. The common theme among these projects is to offer "the kit building experience". But I think for some projects, that's a way of avoiding the kinds of documentation provided in the past by "commercial" kit producers.

    In 2010 there were enough of these projects, that I moved them to their own Web page. They include projects like P112 Z180 single-board, N8VEM (now projects, projects, and SEBHC. A microSD card product supportable in CP/M had discussion here which was also moved to that Web page.

    But now in the 2020's, individuals produce PC boards all the time, just for sport. People gather around them, interest comes and gos for many. So I'll leave it to web-search to inform others about who and where they are.

    Who has / had S-100 systems?

    In April 2006, I started a page for owners who show off their WORKING S-100 systems. There may also be some S-100 owners in my links to S-100 sites below. But my owner's page will be for people who own and operate just a few systems, most of whom don't have Web sites. Look for them at my S-100 owner's page. ALso see my Web pages on repair, restoration and preservation efforts by myself and others, on computers of the 1970's and earlier.

    In the 2020's, S-100 owners may post in social-media about their systems; or in discussion group "blogs" or "wiki's". Some provide Web pages. Again, I'll leave it to web-search or social-media search to find these.

    Pointers to S-100, CP/M and Related Sites

    links for 2021

    late 2021: the "maben" archive of vintage computing documents, which resided at for many years, is apparently now a private archive on github. Rules for obtaining access include certain obligations; read the page for details.

    links for 2015

    Miguel Garcia aka FloppySoftware, has a Web site where he discusses Amstrad, CP/M, and related history and products. He also has a number of CP/M software programs he has created or modified, freely available. Here's the English-language version of his CP/M-and Amstrand oriented Web site. He also has a blog site and Spanish-language sites.

    links for 2014

    On late April 2014, the 40th anniversary of the first operation of CP/M, the IEEE awarded Kildall's CP/M as a Milestone in Electrical Engineering and Computing. The IEEE and the Computer History Museum put a plaque near a building housing Kildall's first DRI office. Here's a link to a brief reference to the IEEE 2014 Milestone Award to Gary Kildall. The reference links to a larger history of CP/M, Digital Research and Digital Systems on another part of my Web site.

    links for 2013

    In most cases, when someone requests "a copy of CP/M", they mean a bootable CP/M disk for their model of CP/M computer. One person who provided many CP/M boot disks in the 1990's was Don Maslin. As of 2003 there is a on Gaby's CP/M Web site, a list of what were maslin's available system disks.. Don Maslin passed away on Sept 10 2004; his archive became unavailable. But in 2012, Al Kossow of and the Computer History Museum, acquired and distributed a copy of two tape backups of Don Maslin's former computer. Here's a Web page with a 200MB copy of Don Maslin's files, which include Teledisk images of many vintage system disks. To use these images, see my discussion of how to write CP/M disks for your computer.

    links for 2012

    Dec 2012: Bob Bybee, a supporter of the Polymorphic line of S-100 systems, wrote recently: "I’d like to introduce you to [my] new site about the Poly-88 and System 8813. Please poke around, enjoy, and let me have your thoughts and suggestions." is "no longer in service" but as of 2021 a copy seems to be at

    Jan 2012: The MESS site supported emulator for various old computers, including a lot of S-100 type systems. Even if you don't use the emulator, you might get some technical info about the system from the emulation files. I first noted this site here in 2001. MESS evolved over subsequent years, merged with MAME, and as of 2021 it appears to be at this Web site.

    links for 2011

    Dec 2011: The domain has added an "Humgongous" archive of CP/M related archives, some time recently. Some of these are Web links to other archive sites, but a number of them are resident archives. Among these are archives referenced on this Web page, including the "Walnut Creek CP/M CD-ROM" and the old SIMTEL CP/M archive. Also private archivse like Rlee Peter's personal collection, Gene Buckel's, Thomas Scheerrer's, Chuck Falconer, Hal Bower, and on and on....

    Sept 2011: Stewart Kay contacted me in Sept 2011 with this request: "I've been searching for [a piece of CP/M] software called "Software Music Synthesizer System" or SMS. Jim Battle has the manual for it on his SOL20 web site at . There's [an apparent derivative] for the TRS-80 computers [called] Orchestra 80 or 85 or 90. [The program's author] says he didn't keep any copies of the old 8080/Z80 code." If anyone has this SMS software, contact me and I'll contact Stewart.

    Stewart Kay is also the author of a Microbee system emulator for Windows and Linux called ubee512, formerly made available at the freshmeat Web site. [2014: check the Microbee preservation site.] The Microbee was an Australian Z80 system with video graphics and audio, sold as a kit and published in a magazine. Applied Technology designed and owned the Microbee product (1982), and they were involved with S-100 systems as well. Numerous games were produced for it, and a number of models were produced for personal and educational markets. Part of the emulator's support software is a diskette utility program called "ubeedisk", which reads and writes Microbee and other diskettes. See my Web page on floppy read/write software for details.

    Aug 2011: I did a search for Intel Multibus-related document sites. Other than the last of the Multibus I commercial resellers and rebuilders of Multibus products, and "", about all I could find with anything comprehensive on line was this 2006 site by "Joe" on Joe Rigdon shows several systems and lists many manuals he has. Possibly this is a recovered "lost" Web site. There are a number of other Web pages, by individuals who have or had Multibus systems. By the 2020's, interest in Intel Multibus development systems increased. and of course, "" has a lot of Multibus documents.

    I was contacted by "Giles" who has assembled a Z80 and CP/M 2.2 system from scratch. Not too many people today build their own Z80 system, chip by chip, with wire-wrap. Giles describes his activities as a series of upgrades. This is how it was done decades ago, when these chips and capabilities emerged one by one. He has some other projects too on his site.

    THere's a new SASI to IDE drive controller board for the Heath H-8 amd H-89. IT was designed in 2010 by Noberto Collado. Here's Noberto's H8/H89-Z67-IDE Storage Controller Web page. NOte that this board works with his redesign of the Heath Z67 SASI interface card for the H8 or H89. Look elsewhere on his Web site for additional work on his H-8, purchased originally by him back in 1878! He's designed a number of cards and now participates with SEBHC, a Heath computer support group.

    Early owners of the MITS Altair 8800 were members of the Homebrew Computer Club in California. Here's the 2006 first-person account of Bob Lash, a HCC member. He was typical of the techies who were in the process of building their own computers from logic IC's, as microprocessors were becoming available but were too expensive to buy. It was the low price of the Altair 8800 (and other early microprocessor products) that broke the price barrier and started the "microcomputer revolution".

    From comp.os.cpm discussion of Windows programs to unpack CP/M "library" .LBR files, I found a Web page for the Linux "lbrate" utility. which also un "crunches" files. For non-Linux users the sources may be informative. There's a similar utilit for .ARC files. The page refers to this Web site of Linux compression utilities to obtain the files. Buried in the README (not on the Web site) is the author and presumably Web site owner, Russell Marks.

    Later discussion of CP/M decompression included remarks from Peter Dassow who offers both MS-DOS and Windows versions of an un-library and decompression program.

    microSD card products are supportable in CP/M as discussed in Feb 2011 in comp.os.cpm. I've noted two Web sites with more information about use in Z80 or CP/M enviroments, and the Web links to the hardware products.

    Feb 2011: I recently learned that Barry Watzman, a Heath computer developer and supporter, died in May 2010. Read this Web page for details and some tributes.

    Jan 2011 - John Elliott announced in comp.os.cpm: I've now written an emulator which emulates enough of ISIS to run [PL/M ISIS] tools under Unix. I've also made an updated with Unix-y build scripts rather than DOS batch files, which may find its way to [CP/M archive site] in due time."

    There's also a note on comp.os.cpm, referencing a Web page by "Hector Peraza?", about original CP/M based ISIS emulator called ISX, on the "Sourceforge" source code site for the P112 computer. The Web page describes the disassembled ISX emulator, and discussion about how to run it under CP/M 3.0 (?). The page was last updated in 2007. The P112 is a Z180 computer offered in the 1990's and again over a decade later.

    links for 2010

    Nov 2010: There is an Australian Microbee preservation group, the Microbee Software Preservation Project (MSPP). There's a forum and a software and firmware repository. The Microbee was first produced in 1982 and forwards, as a Z80 system with CP/M on floppy and a Synertek 6545 CRT for video. Founders of the company previously produced S-100 cards as "Applied Technology". It's not clear from other references, if the MicroBee itself was S-100 capable. (From comp.sys.tandy posts and notes in Wikipedia, and from notes on the Applied Technology page of .

    Oct 2010: In response to my question about active BBS's, John Crane posted in comp.sys.northstar: "These BBSs are definitely "endangered". I remember when there were 100+ in my state alone. Now the [dialup] list is down to 31 total. [Lists are maintained on this linked Web site page.] I also use [my NorthStar Horizon] as a terminal to a local Unix machine, so I get netnews, telnet, ftp, etc. through the Horizon as well. Pretty useful for 70's tech. And it looks good sitting on the desk with an aluminum Hayes modem on top. No Chinese plastic anywhere!"

    Crane continues: "In a similar vein, one of my IMSAI's was used to run a BBS back in the 80's The hard drive is still loaded with all the software and I've toyed with the idea of bringing up a BBS catering to the vintage computer crowd. But I figure I'd spend a week or two getting everything to work the way I want and then maybe 5 guys call it in the span of a year. So I never thought it worthwhile. - John"

    Dave Perrussel, who operates the Web site, had a response in 2010 to the above comments: "BTW - there are more than 31 BBSes out there. It's in the neighborhood of 400. It's that the old school dial-up BBS is almost but gone. The rest are [reachable by] either Telnet or SSH." I acknowledged his support, for listing non-Telnet dial-ups on his site. However, his site say BBS systems were "developed back when MS-DOS was king". When I challenged him and said that dial-up BBS systems began with the computers of the 1970's including CP/M systems, he claimed BBS's "really didn't become popular until the 1990s". I often run into an argument that CP/M and 1970's systems were not "popular", and therefore they don't really count. So being first doesn't count? ;)

    Aug 2010: Dave Griffin was again offering the P112 Z180 single-board computer. Here's a link to a few more details and other Web links. There are earlier mentions of this kit in older links below on this page. Note: Griffin cancelled the offer due to lack of presales, in Oct 2010. But the link references some P112 archives and others have since built variations of it.

    Also in August 2010: F. J. Krann has some information on the WD1002 board on his site. It's an old SASI to floppy and hard drive interface card. He found information apparently at as well.Krann has a lot of other information about vintage computers as well. THis month, he's working on a pair of ECB (Eurobus) video cards with the NEC NEC7220D video processor chip. Look around his site for info.

    July 2010:

    In July 2010, I was contacted by Pascal Microengine owner M. R. Wigan. On his Web site he discusses the history of Western Digital's hardware chipset and products that were used for UCSD Pascal, Ada, and DEC's LSI-11. I discuss Pascal and more about Dr. Wigan on my Pascal Web page. He is also a current and early member of an Australian computer club still active today. He discusses the MICOM club on this page of his site.

    june 2010: James Moxham, AKA "Dr Acula", is working on a wireless network using Z80's (both real and emulated), CP/M and MP/M. His network was a mix of N8VEM Z80 systems, Microchip Propeller processor boards running emulated Z80's under "ZiCog", and some sensor nodes using the PicAXE processor. Discussion is over several Web sites and several blogs - I don't pretend I can follow it all. A little discussion survived into the 2020's at this Web link.

    April 1st: Ed Roberts, S-100 creator, died April 1st 2010. Follow this link for more information.

    In March I was looking around the Web, and happened to find This "ISO 7185 STANDARD PASCAL" Web page. It's a current and comprehensive site for Pascal compilers past and present, and supports current Pascal international standards. There's also a complete PDF collection of the "Pascal Users Group" newsletters, from the 1970's when they were a part of microcomputing history to may Pascal readily available. The "P code" interterpreter to run the Pascal compiler is very portable and many early Pascals on minicomputers and microcomputers used this scheme.

    A Feb post in comp.os.cpm refers to the YASBEC Z180 single-board computer, first offered in 1991. The poster notes that an archive for YASBEC docs is at the "maben" archive site.. Another site with YASBEC information and software is at this copy of Hal Bower's 8-bit Web page section, where he offers software he developed for the product and other Z80/Z180 systems. It's in a compressed format of LBR and LZH files. To decompress Hal's .?y? LZH 2.0 files, I found an archive of Jay Sage's ZNODE3 with this UNLZHCPM program in MSDOS which will apparently decompress Hal's files in an MS-DOS window of Windows.

    One CP/M file archive site is this Web site by Marko Mäkelä at These seem to be copies of a former archive at .Many of these archives are compressed, and old CP/M compression schemes vary a lot. The "CP/M FAQ" says to look at Simtel's MSDOS archive under "compress", to find MS-DOS utilities to decompress them.

    links for 2009

    Nov-Dec 2009

    In usenet group comp.os.cpm I saw a reference to a DOSBox project with a DOSBox web page at this link.Its' another open-source Intel/MS-DOS hardware emulator. It seems to support older and more general hardware than some, the page mentions 286/386 hardware, as well as emulations of various IBM PC classic hardware. It's mentioned as supporting CP/M-86. But SIMH is often the emulator of choice among vintage system owners, for supporting older mini and microcompters.

    Dec 2009: Stewart Kay posts in comp.os.cpm about the Z80EM86 Z80 emulator he wrote in the early 1990's, and has recently re-released. "Z80em86 is NOT a CP/M emulator. It simply emulates a Z80 CPU (documented instructions only) and also has some support to emulate various bits of hardware that would be required by an operating system. The README file describes z80em86. There is a CP/M 3 operating system I wrote that can be booted by z80em86 but the emulator can run any operating system if one wants to code it up, and the documentation has the necessary details for doing so. The CP/M 3 system has a README file that describes the operations of the system." The emulator runs as a 16 bit application in Windows and Linux/DOSEMU. In 2021, the only thing I could find was z80em86 sources and binaries apparently saved at the CP/M Archive.

    The last editor of The Computer Journal, a small press publication on microcomputing, has now PDF'ed all the back issues of that magazine and put them on his Web site. Bill Kibler of Kibler Electronics has an archive of TCJ on his Web site.. I wrote about a dozen articles on S-100 for TCJ. A number of developers in the 1990's published articles in TCJ.

    A Windows diskette imaging utility called OmniFlop, has apparently been around for a few years for the BBC/Acorn/Spectrum community. This Web page describes OmniFlop.. There's a companion OmniDisk for MS-DOS.

    Here's a Z80 and FPGA project I came across. The V6Z80P is a Z80 associated with a Xilinx Spartan II FPGA, on a surface-mount card developed by "Phil" in the UK. The FPGA supports video and other interfaces, and is reprogrammable so part of the development is on the FPGA side. I've emailed him, he's been very kind in his discussions with me. He says he may order some boards and parts in NOvember 2009, which he assembles and offers when available. It's a "hobby" project so his price reflects costs, he says. As of the 2020's, I've updated the Web link; he still sells parts but this project may be retired.

    Sept 2009

    There is more work on the YAZE-AG, Yet Another Z80 Emulator by Andreas Gerlic. While 2.20.1 was the latest and "last" completed version, a version 2.30 is in development as of Oct 2009. "yaze-ag is designed to provide an exact simulation of the Z80 microprocessor on a UNIX (Solaris), Linux, FreeBSD, Mac OS X or Windows system (cygwin environment)." As of 2021, the final release was

    The German site, has a section of photos of computer boards including S-100 cards called "the PCB-Gallery". The photos are well-taken with good lighting. The site is otherwise in German, but Google offers translating services. For English-only speakers, German with technical content is somewhat readable.

    June-Aug 2009

    Mike Sharkey had sme Z-80 and S-100 Web pages.He's working on a Z-80 software emulator and has a S-100 system he's working on. He also designs digital electronics and his site supports his aviation work. IN 2021 I found his work on github (microsoft)

    The Norway-based (Dutch-language) site of "Katzy" has had some Dr. LOGO documents from Digital Research, as provided via Emmanuel Roche. By 2009, there are more Dr. Logo programs there.

    John Monahan wrote to me and said: "I am now in the process of putting together an S100 Web site. I have started off with hardware & software discussions about the board(s). While the site is still not ready for general consumption I thought you might like an early look. Any comments/bugs etc please do not hesitate. Check my notes above for details and current status.

    In a private email, Les Bird of the Society of Eight-Bit Heathkit Computerists (SEBHC) archive site alerted me to that organization and their Web archive. Check my notes above for details. The SEBHC site has moved a few times, as of 2021 it's on github and also has a google discussion group.

    may 2009

    Noted in comp.os.cpm was a Web site which offers a 1980's CP/M compatible Z80 OS called "QP/M". Microcode Consulting's QP/M is noted to be CP/M compatible but adds features like date-stamping. BIOS for a few specific Z80 systems are also offered. Additionally the site offers plug-in BIOS support for hard drives, debugging tools, and an assembly linker. As of 2019, these appear to be free but without warranty.

    Random Web search for "compupro S-100" found this article from May 2009 in The Register UK, on Rik Myslewski's 1982 assembling of a Compupro system.

    In comp.os.cpm in early May, someone posted this Web link to by Dennis Kusche. The site supports a TTL-based 8-bit computer, which apparently has most of the capabilities of a simple, modern personal computer. It includes compilers, Ethernet and TCP/IP support (the site operates from one model!), VGA video, IDE hard drive, and more. The card size is the small Eurocard; it takes six cards to make a minimal system. More interesting, there is a Homebuilt CPUs Web Ring and this site is a member. Apparently, there is a German Web site and company which offers something about MyCPU.

    In comp.os.cpm in early May, Andrew Lynch announced a proposed "new" S-100 six-slot motherboard, with termination very very similar to the Compupro design. Lynch developed this as an adjunct to his N8VEM Z80 Eurocard-bus computer project, which he has offered as open designs and at-cost circuit boards for a few years. N8VEM became, follow the Web link.

    In comp.os.cpm, Dave Griffith announced he may make another round of P112 boards. The P112 is a Z180 computer originally designed and produced by David Brooks of Australia in the 1990's. In 2004 and forwards it was independently produced (intermittantly) by David Griffith. It incorporated a GIDE like interface. For more info and links, check my P112 notes.

    April 2009

    A New York Times video Feb 05 2009 on Halted Specialities which has sold surplus electronics in Silicon Valley for decades.

    In April 2009, Marcus Bennett posted in comp.os.cpm on converting 3.5-inch floppy drives to work as 8-inch drives. "Dear All: Get ready to use 3.5 inch diskette drives instead of those big and noisy 8 inch drives on your Cromemco (and therefore any other CPM) genre computers .[link to blog entry at has expired]". I reference this also on my Web page of diskette drive technical data. In the years since, many people have modified certain 3.5" floppy drives to run at 350 RPM and act like 8-inch floppy drives.

    In 2009, J G Harston posted in comp.os.cpm: "My Z80Tube [emulator] has been happily running on my 16M ARM7DTI coprocessor [as on this Web page]. IN private discussion he told me: "It runs on an ARM. It will run on any ARM OS that provides the minimal core ARM I/O calls (OS_RDCH, OS_WRCH, OS_File, OS_Args, OS_Find, OS_BGet, OS_BPut, OS_GBPB) such as Arthur, RISC OS, RiscIX, ARMTubeOS, and various ARM development system OSs. It should run on ARM-based Linux, but I don't have the ability to test it."

    "There's also a 'C' version which will run on anything that will compile 'C' code at the mdfs site. I've had that working on Windows 3, 95, 98, NT, 2000, XT, Intel Linux, ARM RiscIX, ARM Linux, ARM RISC OS, Intel DOS. Somebody reported it running ok on a Mac."

    A customer asked me about SCION (brand) Microangelo documentation which I did not have. In looking around the Web, I found A private Web page on a Microangelo redesign by Dwane Elscott. He describes S-100 as his "first home computer" and also at his first professional job site, where they used the Microangelo. He wire-wrapped a "clone" at home. Years later, although he acquired that computer from his company, he designed a compatible board set to run from his Zerox 820 and other CP/M computers. Details of the design are not on his site, but it's a typical story from the era. Butg by 2021, the private site is gone.

    Did you know that AutoCAD ran on S-100 boards?. In this interview of AutoCAD co-founder and first CEO John Walker, by Kean Walmsley in 2008, Walker says the Marinchip 9900 S-100 graphics board was AutoCAD's first hardware platform. A photo of him with this card is on Walmsley's blog Web site. Walker has written an on-line book about AutoCAD's early years, which is on his Web site. It's in large part an accumulation of company documents and notes. (It also happens that I have a Z-100 version of AutoCAD.)

    mar 2009

    Alex Freed and his Apple II Z80 card were mentioned a few times in comp.os.cpm. The Apple II could run CP/M 2.2 or CP/M Plus thanks to a slave Z80 card. A number of companies made these including Microsoft. Alex designed his own in 2008-09. IN 2021 I found some surviving version as Project 26 on this Web page.

    Feb 2009:

    I had some discussions with Jonathan Graham Harston about the Z80 banked memory hardware he mentions on his Web site. This was part of a recent comp.os.cpm discussion about MP/M memory management. The link in this note is to my 2005 link to his Web site. By the way, his site was part of the CP/M Web Ring. Web Rings are (or were) an aggreate of Web sites on a common topic, linked via a service so you can hop "around the ring" of associated Web sites. However, the CP/M Web Ring appears in 2009 to no longer exist. And by 2021, the service no longer exists.

    PASMO, A Z80 cross assembler which also generates 8086 code, appears to be available from Julián Albo at his Web site as linked here. He also has a Z80 emulator. These are programs in C++ but a Windows version is provided. And, there are some Z80 programs as well.

    Bob Stek, "saver of lost Sols" announced in comp.os.cpm that he was "retiring" from his decades of work with Processor Tech "Sol" and other early computers, and selling his collection. It's a loss of sorts but others will get the benefits of his accumulation. One of his colleagues who responded to Bob's post is Jim Battle, whose SOL-20 Web site covers that system and provides a lot of resources.

    Jan 2009: I was pleased to get an email newsletter from Bruce Damer of DigiBarn, a well-known museum and archive of microcomputing. One item in the issue #23 newsletter caught my attention; the acquisition of a hard drive based 8008 system from 1972-3 from Bill Pentz. He and others did this at California State University, Sacramento and called it the COMERs (COmputerized MEdical REcords System) system. details and Bruce's account of that system and its acquisition is linked here.

    links for 2008

    Dec 2008: I don't know why I don't have Web links here, to one of the most popular C compilers for CP/M: BDS C by Leo Zolman. Leo released his sources in 2002 on his Web site. Here's a nice interview of Leo Zolman by Jim Lawless, on Jim's Web site.

    Dec 2008: a discussion in comp.os.cpm about the Borland museum of freely-provided software from the former Borland company, led me to check the museum's status. Links to the former Borland Museum Web pages seem to now go to a software museum section of Embarcadero Technologies. They apparently bought "Codegear", the "Developer Tools Division of Borland", on July 1, 2008 for approximately $24.5 million. They appear to continue to offer some of the old Borland products for download, after some kind of registration. The site was slow to respond and I did not investigate further. HOwever, some noodling around found these Codegear links to download versions of Turbo Pascal, Turbo C and other products.

    A note in a Codegear blog of Borland Vice President David Intersimone for May 2 2008 notes that 25 years ago to that day, Borland was founded. The note has a timeline by year for various Borland products, starting with Turbo Pascal, released soon after the company was founded in 1983. The blog contains additional posts by Mr. Intersimone and others about the early history of Turbo Pascal and Borland.

    By 2021, "" was no more. In 2015, Embarcadero was bought by Idera, Inc. The embarcadero Web site exists, possibly some Borland stuff is hiding there. But there's other resources to find these ancient products.

    Dec 2008: in comp.os.cpm Bill Buckels who has archived some C compilers for CP/M showed an email from Dennis Saunders of Mix software. Saunders of MIX Software "released" Mix C for CP/M for general use. Thanks! MIX Software also offers other MS-DOS and Windows products at pretty modest prices.

    Dec 2008: in comp.os.cpm, a freeware product was mentioned which led me to Herne Data Systems in Canada. They apparently have a freeware product for the Commodore C128 called "jugg'lr128" to read multiple CP/M formats; and a free or pay MS-DOS or Windows "FreeForm" product (not very expensive, $25 canadian) to do the same. Another MS-DOS or Windows product does specialized disk formatting. I have not used or evaluated these products.

    Oct 2008: Rich Cini, of Altair32 fame (an Altair front panel hardware emulation) reminds me that a lot of his accumulated docs and projects are on his section of the classiccmp Web site. There's a variety of microcomputer brands there, including some S-100 stuff; and links to his Altair32 and other pages.

    Sept 2008: Bill Buckels mentions in comp.os.cpm his Official Aztec C Museum Web site is looking for more Aztec C products. The owner of the copyright, Harry Suckow, supports "fair use" of these products. See the site for details. Aztec C supported many microprocessors and ran under many operating systems.

    Bill began his CP/M archive on his own Web site, months ago. Apparently Manx Software "disappeared" and showed no interest in these products; Buckels made quite a point about this. There are Aztec C compilers and cross-compilers for the Z80, 6502, and 8086 processors and for corresponding systems. Anyway, he had quite a collection of them on his site; then he developed the Aztec Web site referenced above. Bill continues to work on and add to this site. As of Dec 2008, he plans to add Mix C tools, with permission. Thanks!

    Sept 2008: With encouragements by Emmanuel Roche, Janny Looyenga, a Dutchwoman known as "Katzy", has provided DR Logo on her Web site.DR Logo (for Digital Research, not "doctor") is a graphically oriented language which runs under CP/M-86.

    Aug 2008: In comp.os.cpm, there was an announcement of a retro-computer show as part of a computer festival in Russia! Here's a Russian page describing some of the 8-bit computer activities. Europe has a great interest in things Z80, and Russia made some notible Z80 home systems. The same announcment mentioned a project to copy the Vector-06C.

    July 2008: In a comp.os.cpm discussion of networking and CP/M 2.2 on the Z80 the KC85 computer was mentioned, because of some networking software added to that system. Briefly, the KC85 was an East German Z80 system, to which a version of CP/M was ported. At the KC85 Web site of "susowa" of Germany are notes about that computer (in German) and about "KCNET", a TCP/IP and Ethernet network adapted to that computer. Note: the site uses .PMA compression, an MSX standard. This MSX site has decompression tools for PMA files. [In 2011 the KC85 domain was changed, follow this link.] In 2021 I could not find the site, but Wikipedia has some KC85 links.

    July 2008: As part of a discussion about networking (TCP/IP) and CP/M in comp.os.cpm, the Z80 and amateur radio packet networking package "KAQ9" was mentioned. Someone was kind enough to post a link to an archive of that 1992 work. This appears to be an archive of KAQ9 from 1992 of Phil Karn's work. Apparently it could be assembled and compliled (in Borland C) for the IBM PC and MS-DOS, the Amiga, CP/M or Unix. There are also references to "NOS" and a number of variations NOS (GPSNOS, WNOS, etc). The archive linked here, appears to be an old 1990's Ham Radio archive of TCPIP software used by radio amateurs in the 1990's for packet radio: there may be other such archives if this one becomes lost. By 2011, I compiled a We page on early packet radio and KA9Q.

    July 2008: In a comp.os.cpm discussion of use of CP/M-86 on "modern" Window/Intel PC's, Peter Dassow notes: "Couldn't believe that you don't know all existing possibilities for CP/M-86. There is an "AT-Patch" which helps exactly for resolving that "no boot" problem [at this link] [at the CP/M-86 Software Repository]. Also there are a lot of other patches, e.g. to get 120Meg instead of 8Meg for the harddisk space [at this link] and so on. Unfortunately [this] is now only a mirror [of] Kirk Lawrence's site, but better than nothing ( )." In 2021, the site is still there!

    CP/M critic Emmanuel Roche posts in reply: "Yes, you are right: this is CP/M-86... That is to say: BDOS Version 2. [note that if] you go on Kirk Lawrence's Web site, you will note that: "Much of it will NOT function correctly under other permutations of CP/M-86. YOU'VE BEEN WARNED!" And CP/M-86 Plus uses BDOS Version 3 (that is to say: biggest file: 32MB, biggest drive: 512MB, biggest configuration possible (16 drives of 512MB): 8GB. We are not talking of 8MB. And Concurrent CP/M, as its name implies ("Release 3.1") uses BDOS Version 3 (like MP/M-II). [It is an] 8086 version of CP/M Plus with 4 background tasks, and a 8086 version of MP/M-II with virtual screens."

    Late June 2008: I stumbled across A Web site on Jon Titus and his Mark-8 8008 computer. It's apparently a 2007 Web site for an IEEE Computer Society student competition, at Florida Gulf Coast University. Jon Titus gave them an interview about his Mark-8 development; and they have archived an earlier interview he gave on the subject. Jon is a true microcomputer pioneer; he and his colleagues taught the people who bought and built and designed the microcomputers of the mid-1970's. Over the years, I've encouraged this university to maintain this Web page; stop by and give them a hello.

    In June 2008, Howard Harte announced in comp.os.cpm that his Web site, has a set of files or links to a number of Seattle Computer Product's 86-DOS programs, disks, and manuals. There is also a version of the SIMH emulator to run 86-DOS. SCP employed Tim Patterson to write an 8086 operating system for their then-new 8086 S-100 system. He modeled it after CP/M-80 down to system calls. This was the OS later bought by Bill Gates of Microsoft and sold to IBM as their PC-DOS; and sold by Microsoft as MS-DOS. Some of the Web links on Harte's Web site are to Tim Patterson's site. But when I checked in 2021, the Web site was about some vague technology "of the future". Wikipedia on 86-DOS has a 2009 archiv e of his resource page.

    I got an email in May, from Alexander Voropay, who alerted me about some Linux related work with CP/M or diskette images. The "YAZE" Z80 emulator has some done as of 2005 on this Web page for YAZE-ag by Andreas Gerlich. Included is CP/M 3.0 BIOS support and some bug fixes. Another classic Linux CP/M package is cpmtools to access CP/M file systems, as linked to this 2.7 version of Michael Haardt's. A popular set of Linux floppy disk utilities is "fdutils", which is described on this Web site.

    In June I got notice of the final version of YAZE-AG - Yet Another Z80 Emulator by AG (V 2.20). Again, the Web site for YAZE-AG is at this link.

    A somewhat hidden Web site has quite a collection of S-100 documents. Check for Marcus Bennett's archive of software and hardware of the S-100 and CP/M era.

    A number of S-100 hardware systems have been added to the SIMH computer simulator for 8080 and 8086 hardware.Check the SIMH site for Peter Schorn's work on SIMH. He has packages for CP/M-80 , CP/M-86, IMDOS (IMSAI's licensed version of CP/M), MDOS (from Micropolis, for Vector Graphic), and OASIS (Vector Graphic).

    On Feb 28 2008, Max Scane announced in comp.os.cpm that the CP/M versions of VEDIT would be released for non-commercial use. Mr. Scane discussed this with the developer of VEDIT, Ted Green, the CEO of Greenview Data Inc, the former CompuView Products. Greenview's terms of agreement for use and for distribution are on the Web site at this Web link. Basically they allow for non-commercial use by individuals, and for non-commerical (no charge) distribution on Web sites. The agreement is interesting in its own right. But this ancient material was not found in 2021 on the Web site. Web search may find it elsewhere.

    While looking at some Web auctions, I came across Richard Pestinger's Web site at this link. He's got a nice collection of early EARLY 8008 and 8080 and 8085 stuff, from the Mark 8 to the Z-100. Nice photos, and some manual PDF's as well. Lots of photos of hard drives, floppy drives and so forth. Some "how I assembled this" stuff. Worth a look!

    In late Jan 2008, Roger Schmidt announced that he's going to offer his 6502 processor- based version of CP/M called "DOS-65". Peter Dassow will provide this Web page for the DOS-65 product which Roger Schmidt produced some time ago. Details of this are not clear; the undated documentation on-site says DOS-65 is still a product and not "public domain, shareware or freeware". The 6502 was developed by MOS Technologies and used in the Apple II, the Commodore 64, and other computers. The manual on site so far refers to the Commodore KIM-1.

    links for 2007

    Dec 2007

    In October 2007, Andrew Lynch announced in comp.os.cpm that others had established a Vector Graphic mail list discussion group. It used "listserv" to manage the list. They also had an archive of VG files and documents. (For more information you'll have to join the list to read the contents.) There is a new Wikipedia entry for Vector Graphic, with more links. By December 2007, Howard Harte announced in comp.os.cpm that he and Andrew and others worked to image several VG diskettes, and to run those images on a version of the SIMH general-purpose computer simulator. The disk images and the simulator are STILL available at a Web page archive also created by the VG discussion group. That's good - by 2021 Vector Graphic archiving became lost.

    Udo Munk announced in comp.os.cpm that he's modified his Z80 emulator, written in C for Unix use, to compile under Cygwin for Windows use. Check his site for details. He has several versions of CP/M on his site, compiled from the earliest sources, for use with his emulator.

    It's been repeatedly argued that the original MS-DOS for the IBM PC, bought by Microsoft from Seattle Computer Products and written originally by Tim Patterson, was "derived" in some way from Digital Research's CP/M 2.2. The arguement is how the "derivation" occurred. In July 2007, a Seattle court looked at this issue as a result of Patterson's lawsuit against author Sir Harold Evans who argued as much in his book, "They Made America", which featured Gary Kildall. This report of the judge's ruling by Andrew Orlowski in the UK Register, says that the judge agrees that functions of MS-DOS were copied from corresponding CP/M functions, and that Evan's claims were largely factual and without malice.

    Nov 2007

    In Oct 2007, Andrew Lynch started a Yahoo! group email list for Northstar computers. But to post you need to be a Yahoo! groups member. Of course yahoo groups went away sometime in the 21st century.

    Saw this site referenced in comp.os.cpm: HD64180 Web site in Germany of Rolf Harrmann. The Hitachi HD64180 is a Z180 version processor. The site has source code and binaries, English speakers like myself can probably sort out the German comments.

    While searching for original CPMUG disk images, I found this Web site: the German ZNODE 51 site, which has online archives of the FOG (First OSborne Group) disks for CP/M and CP/M+Plus and for the PCW. Also NZ-COM and Z3PLUS operating system stuff. Another source for CP/M programs!

    June-July 2007

    A useful site for comparative information on computer bus structures is at the Bus site. They recently added a S-100 bus description from me. But checking there in 2021, they seem to be some vague site about PC-related stuff.

    In June Miguel Garcia posted in comp.os.cpm: I have created a "C Compilers list for CP/M" with links, and information. It covers CP/M-80, CP/M-86, CP/M-68K and CP/M-Z8000. I hope [this list] will be of some interest." the list includes Web links to obtain many of these C compliers. As of 2015 this site is unavailable, see my 2015 links for an update.

    Apr 2007

    The Amsterdam Compiler Kit (ACK) was written decades ago by Andrew Tanenbaum and Ceriel Jacobs, to cross-compile between a number of programming languages and a number of processors. It was written to run on Unix, and later Minix. In April 2007, David Given announced he's successfully migrated and updated a version of the ACK to run in Linux, and it supports the 8080 so far. He hopes to get a CP/M-80 systems library so that the executable can recognize standard system calls from C into CP/M.

    Udo Munk: From comp.os.cpm for late Oct through April 2007, Udo Munk announced his updates to his Z80pack CP/M emulator for UNIX systems. He says the I/O is "well abstracted" and so any Z80 system can be emulated. It supports CP/M 2, CP/M 3, MP/M and CP/NET; and is written in ANSI C. For more information on and Z80PACK, see this section of this Web page.

    In April 2007, Roger Ivie has roughed out a port of Z80pack to Windows, using OpenWatcom C. His Web site appears lost; but eventually Z80pack was supported under Windows.

    Thanks to a post in comp.os.cpm, I've been directed to the "" site of the Disk2FDI support page. This is a project with registered or "trial" software for MS-DOS, to read a variety of older disk formats from Tandy, Amiga, Commodore 64, Apple II, and other older systems. May be of interest to CP/M folks. Apparently uses a few bits toggled by the PC parallel port to read the data, while apparently running the drive from a PC floppy controller (unclear). Of additional interest is a Web document which describes how to toggle Teac 5.25" drives to speeds of 300 RPM or 360 RPM, with Teac Web links. That page has a copyright notice that I can't parse so I won't link to it.

    Mar 2007

    Mar 17th 2007 in comp.os.cpm by Jeff Armstrong: he has updates for DEC's version of their use of GSX-86 graphics, under Mark Williams C for CP/M-86. Jeff's versions are available for MS-DOS under MS C 5.1 and OpenWatcomm C 16-bit. Nowithstanding the MS-DOS side, this may be convenient for CP/M-86 users. By 2021 I could not find Jeff's work but read more below ...

    A March 15th announcement in comp.os.cpm by John Elliot: "I've recently had a stab at converting my source tree for the GEM video drivers so that it builds GSX-86 video drivers instead. You can find the results [at this page]. The testing I've done, such as it was, was under GSX for DOS; but I see no reason why the drivers shouldn't work under GSX for CP/M-86 as well. The drivers include a number of useful [VGA and VESA] resolutions....Let's see how GSX-86 programs get on with them." -- John Elliott

    Peter Dassow has a Web site for MSX computing - that's Microsoft's 1981 attempt at a standard Z80/graphics computing environment. Peter has discussion and code for a CP/M 3.0 that runs on some of these MSX machines. Announced in comp.os.cpm on March 15th 2007.

    Jan 2007

    An updated version of the SIMH emulator for the 8080 and Z80, configured for the MITS Altair 8800, has been updated and is available for download Peter Schorn's site.. The simulator includes C source as well as executables for PC's and Mac OS X and OS 9. Looks like he also offers versions CP/M and MP/M and PL/M for the 8080, and CP/NET with TCP/IP support; and other CP/M-like OS's. A number of popular programs are apparently packaged with the simulated disk images.

    Got some correspondence from someone in Aug 2007 as follows: "The SIMH emulator emulates Altair 8800 well enought to run CP/M. It supports both 8080 and z80 versions. Check this Web link for details. There is a software kit also, to run CP/M under Windows (a precompiled SIMH binaries and disk images). But that would be an OLD Windows, by 2021.

    Schorn's work above is very close in time to similar DRI OS work by Udo Munk. Munk continued into March 2007 to work on DRI support inside his Z80PACK, a Z80 simulator.

    links for 2006

    Dec 2006

    Piergiorgio Betti developed part of his Web site in 2006 to mirror a number of CP/M archives, some CP/M and Z80 Web links, and has started to archive some material as well. Check his home page for links to areas of archives, mirrors, and links. By 2021, he's added a lot more content.

    Dave Dunfield's section on the "classiccmp" Web site has substantial information on S-100 systems. He also has established, in my opinion, the "standard" for re-creating system boot disks and for tools to manipulate them. In 2006 he moved much of that information to the "classiccmp" Web site. Look at his collection of old computers index page which leads to a variety of systems, boards, documents and software. Also Check out his Disk/Software Images page and his use of Sydex's Teledisk and Dave's own tool, ImageDisk. As of 2007, he provides tools for creating both "imagedisk" format and "teledisk .TD0" format images, and to convert between them; so either of the corresponding tools can be used to recreate those disks. Details and links are described on my "how to CP/M" Web page.. As of 2021, David is winding down some of his vintage activities.

    Sept Oct 2006

    We've had good hardware discussions recently with W Tom Sanderson of The Virtual Altair Museum. He's a former MITS and Pertec employee who has a really good visual Web page of Altair equipment. Some discussion from him is on our MITS/Altair/Pertec Web page.

    July Aug 2006

    A Web search on Computalker, an early speech synthesizer for the S-100 bus, led me to this interview of one of the designers of the Computalker CT-1. The page is part of a Smithsonian project to document the history of text to speech translation. the interview is of D. Lloyd Rice, who apparently owns all Computtalker products as of 1988. see the Smithsonian's Web site for details. [links updated 2008; links broken by 2014, request made to Smithsonian; links found 2021]

    A newgroup post led me to this European Z80 domain which sites some Z80 and CP/M projects by Peter Dassow. He is developing some kind of "CP/M Commander" which mirrors the DOS Commander program of the 1980's. His site also has some Kermit and Commodore 64 support. He at least mentions and displays an Altair 8800, so it's barely an "S-100" site!

    Late in June, Bill Sudbrink posted in comp.os.cpm that he wrote a program to run Processor Tech ".ent" programs saved on cassette tape for the SOL operating system, as CP/M programs. He posted that the code and other details can be found on this Web page. There is an assembly source program there.

    April May 2006

    In May 2006, Rich Cini announced the upcoming availability of his Altair (8800a) front panel hardware emulator Altair32, a new Web site to support and offer it. The front panel itself is a USB 8051-based device; the emulator runs on a PC under Windows. The Altair32 software product, freely available, emulates an Altair in a Windows environment with or without the USB front panel. Rich tells me (Dec 2007) the simulator owes some code to SIMH. By 2021 Rich moved the project to classiccmp

    In May 2006 in a comp.os.cpm discussion of Kaypro CP/M systems, this link was posted to mrynet domain's Web page of Kaypro software and docs and projects. There is also a link to Morrow MicroDecision information at this Web site. There is other info at the site as well.

    In April 2006 I stumbled over this PC-history Web site which has a chapter about George Morrow, a first-person account by Stan Veit written around year 2000. Since Veit's death the site has been maintained and preserved. Accounts of other computer manufacturers include Heath/Zenith, Imsai, Altair/MITS, and various non S-100 systems.

    A recent FTP site in the UK for CP/M and other old computer stuff is at this FTP link on the Landover Amiga BBS Web site by Lance Lyon, in their "classic computer" section.[dead link in 2008, good FTP link in 2021]

    Jan-Feb 2006

    Mike Sharkey informed me about his work on an 8080 simulator: "Oh, by the way, I just finished developing a pretty darned good (if I say so myself) graphical 8080 simulator that runs on Linux. You can download the source code at this location. It requires the Qt library development files in order to build. Right now it loads binary files only starting at address 0000, however, a future revision will load Motorola S-records or Intel HEX format." Note: by 2008, the Web site was not on-line except as an archive found in "Google Code Search". But I was informed Sept 2008, that Sharkey's code was based on work by Kurt Theis; Theis advised me to check his Web site for Sim80.

    In comp.os.cpm for mid Jan 2006, Steve Walz announced he has some Kaypro ROM images at this area of his Web site. Looking around his Web site, he has some other bits of software for MOrrows and other vintage systems. May be some S-100 stuff in there.

    links for 2005

    November-December 2005

    In newsgroup comp.os.cpm for late November 2005, there was a post by Ephraim Moya, in response to a person asking about how to develop a CP/M for the MicroBee. I've copied that post here with permission. He posted, "You might be interested in my old files. [this link to his site]. There is an assembler, a c compiler, a linker, a librarian, etc. I've also released my old modular BIOS for the cp/m board I used to manufacture. These are all specific to my board and to the Z180 but the assembler, compiler, etc all work on vanilla cp/m. I have written a cp/m clone for my board. If there's any interest I'll find it and post it too. Take a look." - Ephraim F. Moya. But nothing can be found for this work in 2021, the Web domain given is out of use.

    June-july 2005

    Two German CP/M Web sites of note. One is Club CP/M which appears to be an active organization supporting CP/M. The other is Prof 80 which appears to be a site supporting a Prof 80 computer, a Grip 1 computer, and a Prof 180 computer - all Z80 machines running CP/M 3.0, including some downloadable disk images.

    Here is a Web page for an XOR computer from Delta Products. This is an S-100 computer, owned by Jim Battle. Jim has several old computer Web pages, all linked from his "junk" home page. They include the XOR, SOL 20, Sage II, Bondwell, and some others. The XOR and SOL are S-100 systems. He includes a variety of software with photos and technical information on the computers themselves.

    In late June 2005, comp.os.cpm had a thread on "C vs Forth on the Z80" which includes some Web links. The links there are now dead in 2021, but Brodie's page also links to the SourceForge "Thinking Forth" project page which includes a PDF of his "Thinking Forth" project. Brodie also links to his books for sale: "Starting Forth" is his classic Forth book.

    Long ago, there was an Internet discussion group (but not Usenet) for CP/M called "info-cpm". I found an archive recently of these messages at this Web site, for the period of 1980 to 1993. Apparently the messages began in 1979 but they are not available at this site. Jon Ripley apparently operates this personal site; his interests include 8-bit (BBC) Acorn computers. There are a few other archives of these info-cpm messages on the Web, and there is one on the Walnut Creek CP/M CD-ROM. [in 2014, later in 2021, the site appears entirely private and Windows-ie]

    April 2005

    Al Kossow's "bitsavers" archive of CP/M and other older computer software and documents had changed to its "" location, apparently as of late 2004. These pages are mirrored on a number of sites, listed on that page, as follows: (all) (all) (pdf) (pdf)

    A lot happened since 2005, but there's still an I believe in late 2021 it was rehosted to another server.

    Feb 2005

    There has been a lot of discussion from David Dunfield in 2004 and 2005, in comp.os.cpm. Seems he is doing a lot of work on CP/M and other DRI op systems; working with or CREATING 8-bt system emulators; providing diskette images and imaging software; and discussing how to upgrade old systems to use 3.5" floppy drives. Check it out! (See my most current links to his work at this section of this page.

    There is a substantial archive of CP/M programs, information and technical notes on J. G. Harston's Web site at Most of this UK site is oriented to 8-bit processors and the Acorn BBC seeries of computers of some years ago. There is also info on disk drives, media, formats. Look it over as there is a variety of stuff there. Relevant to CP/M is the CP/M section. Also look for Z80 and other sections. (In 2010 he updated a 1MB RAM bank switch scheme that is reasonably simple to implement. It maps 1MB into 64 4K pages.)

    Jan 2005

    At comp.os.cpm in Jan 2005 John Elliot announced a new version of LibDsk library functions . He says "LibDsk is a library that attempts to create uniform functions for accessing discs and disc image files." Apparently it runs under Linux, MS-DOS and Windows, depending on how you compile it. Keep in mind it is a LIBRARY - a collection of C functions, not a utility program.

    An interesting history of the S-100 bus and product lines is on the Computer Conservation Society Web site in the UK. The CCS is associated with the British Computer Society. The history is from a talk "Altair and After - The Original PC" given by Robin Shirley in 27 Feb 1993 and summarized in their "Resurrection" bulletin. I have not checked it for historic accuracy and I don't agree with all the author's opinions, but it's unusual in its technical grasp of the details and scope of time. The CCS publishes a journal about twice a year. (updated links in 2008, found the talk summary in 2021. )

    Here's an odd duck: a Tandy Radio Shack TRS-80 Model III, re-implemented as a set of S-100 cards! Check out David Dunfield's computer museum for not one but TWO implementations! Ugly box however... (See my most current links to his work at this section of this page.

    Links below not checked as of Dec 2021.

    links for 2004

    Dec 2004

    CP/M on the eZ80 by Holland, using a eZ80F91 module (eZ80Acclaim!) by ZiLOG with MMC flash memory add on. Clever! See the Dec 2004 comp.os.cpm discussion group for his thread on this. eZ80 development kits from Zilog (sold by Digikey et al) are available at various prices.

    Here is a restoration of a multiprocessor Compupro system, "restored" in March 2004 by DigiBarn of California, USA. Unfortunately, the restoration was limited to preserving the massive four-backplane chassis, and populating it with various S-100 cards. (Updates to the site say the original system can't be duplicated and the design is lost. It was a prototype for a multiprocessor design to do physics calculations.) Check the DigiBarn home page for details of that organization. The link here is for the multiprocessor system.

    Docs and code for the Exatron "stringy floppy"; as well as data sheets for many Western Digital floppy disk controller chips (1771, 1791, 1793, etc.) can be found at the TRS-80 Web site. The "stringy floppy" product was a custom cassette-tape drive and controller that was sold by Exatron for many computers. The TRS-80.COM site is a popular site for Radio Shack computer enthusiasts. It has many files of documents and software from Tandy for that product line; and manuals and data sheets for related products and parts. In the section on "emulators" you can find a Intel Hex file of the Exatron ROM for a Tandy application, in Z80 code. Disassemble it to use it on other stuff. The manual for programming is also on site.

    (Feb 2005 update) A Web page with nice Stringy Floppy photos is right here. Link posted on comp.sys.tandy in Feb 2005.

    Oct-Nov 2004

    In late November 2004, the current "Cromemco" company said they would not prohibit distribution of their old Cromemco S-100 documentation. See a copy of their email on my Cromemco history Web page. Seems that Cromemco is now a European company which offers some multiprocessor products and also Internet services. Cromemco's web site acknowledges their S-100 origins in 1975 by two Standford University professors (California USA).

    I found an interesting Web page with descriptions and images of the famous ADM-3A Lear-Siegler terminal. This product was offered in the 1970's by Lear-Siegler (as in the private Lear Jet, etc.) Inc. as a kit or a completed terminal. Many minicomputer and (non-IBM) mainframe computers had these terminals connected to them. Later, many microcomputers used the ADM-3 and ADM-3a.

    An inquiry from an S-100 customer Kiel Bryant Hosier led me to his DigiBarn Web site section which celebrates the 20th anniversary of the Mac with exhibits of artifacts from Mac development and use. Very interesting, check it out! He also has an exhibit of "computer art". What is that, I asked? Turns out Kiel has artistic sketches of robots "made" from very old computers, including the Altair 8800 of course. Ask him for details, mention my site if you wish.

    There was a discussion about converting from 8 inch floppy drives to 3.5" or 5.25", on Oct 2004 in newsgroup comp.sys.tandy. One correspondant posted this linkto a Web document, "Utilizing 5.25" or 3.5" media on your Tandy/Radio Shack computer system" by Frank Durda IV. Looks like a good document on using 5.25 and 3.5 inch drives on older equipment.

    Check my floppy drives resource page for current information on this product. (In 2010, they have a new PCI model. This site seems to be a catweasel distributor.)

    Aug 2004

    While searching for Northstar tech info, I came across a personal Web site which describes the early history of Northstar and portrays a number of NorthStar former employees who also gathered with him a few years ago! Check Alan Bowker's Web site for his Northstar tribute and history pages. Alan was a tech support person for Northstar.

    While researching hard sectored diskettes, I found a history of early floppy and hard disk development by IBM on the "Recording Technology History" site [updated link 2008]. The page on IBM's work is not linked from this site's home page. That site refers to the RAMDAC Web page at the Magnetic Disk Heritage Center in San Jose CA, where IBM developed the magnetic disk drive and diskette drive.

    April-july 2004

    A reference in comp.os.cpm in July 2004 on articles about CP/M's GSX, led me to a German site which has archived a number of programs and articles about CP/M products. It's in German (I speak English) but it looks informative, and provides access to German work as well as work done in English. Check the CP/M section of Werner's Home Page. [By 2009, the English home page for Werner's CP/M site is at this link.]"

    April 2004

    Hal Bower's Web site has been updated in late May 2004 to include more classic work on Z80 and Z180 operating systems. [Bower's site in 2008] He has also "adopted" with permission related software as part of his archives. Items on his site include Uzi180, ZsDOS, ZDDOS, and B/P BIOS; ZMAC assembler and Modula; as well as Z-System software libraries. Hal's B/P BIOS is a BIOS to support memory bank switching for CP/M environments and support for SCSI, time of day clocks, etc. Specific computers supported by these products include the MicroMint SB180, the YASBEC, and others. Hal also has a library of diskette formats called "ALIEN" which can be used by B/P BIOS to access a variety of CP/M disks written on other systems; functions similar to 22DISK from Sydex.

    In mid-April 2004, Gaby Chaudry posted the following in comp.os.cpm: "As of today, all unrestricted FOG [First Osborn Group] disks (I think 216 different ones or so) are available for download from ZNODE51. They are in .ARC format to avoid problems when downloading LBR files (some browsers may cause CRC errors because of non-binary downloads). You can access the files at the znode51 Web site.

    In mid-April 2004 in newsgroup comp.os.cpm, Tilmann Reh offered some CP/M Plus programs to "process" MS-DOS disks, as opposed to using Sydex's 22DISK. CP/M Plus is an enhanced version of CP/M. His software is running on a Z180 system. I do not know if the programs he mentions below can be transported to a CP/M 2.2 system and/or a Z80 program.

    He said at the time: "So here are the programs to process MSDOS disks under CP/M-Plus: MSDOS241.COM, MSFORM20.COM, MSDIR10.COM .Take care that these are self-extracting archives for CP/M, not executable under DOS. - Tilmann Reh". As of 2006 the links to those files are obsolete, but his Web site at Autometer is still active. In a reply to the above post, Randy McLaughlin reports "22disk is a pain since it will not run under the NT family (NT, 2000, XP). 22disk will also not do high density under Win98."

    Stephen Mulchay's Web page has an informative document on the history of PC busses and drive interface schemes, which includes the predecessors to the IBM PC's ISA bus including the S-100 bus. He also refers to SCSI, IDE and other peripheral buses. Take a look, this information is hard to find elsewhere.

    Jan-Feb 2004

    Sol-20 Web Page about the Processor Tech SOL, page by Jim Battles. A lot of content including manuals and source code, check it out!

    index and contents of Creative Computing magazine appear to be on this site, which apparently supports Atari 8-bit systems. CC magazine issues Vol 8-11 seem to be scanned and on line. Other, mostly Atair-oriented, magazines are also listed. they have some Morrow articles so my Google search found the site.

    The Heathkit H8 and H19 is described and EMULATED on Dave Wallace's Web site. He has an emulation project which is current to mid-2003 but apparently not all features works under Win 95/98. Although my site is S-100, there is a stong lineage from the H8 to the H89 to the H/Z-100, the last of which IS S-100. And I like the old Heath's anyway. So encourage Dave with his work and maybe to move "up" to the H89 with his emulation!

    Chuck Falconer's Web site includes some interesting CP/M replacements for download. A Z-80 DDT, a CP/M replacment (DOSPLUS), and some other code. Chuck is very active on the comp.os.cpm newsgroup.

    A museum largely devoted to minicomputer and mainframe computing is the Computer History Museum in Mountainview CA. They do have some microprocessor stuff and apparently some S-100 items in their archives.

    The American Computer Museum opened in 1990 in Boseman MT. The collection includes many antique and recent office/business electronic appliances as well as mainframe, mini, and microcomputers. Also many ancient calculating artifacts. It seems to be set up in the traditional museum style as exhibit pieces are in cases and as "diaramas" in a timeline fashion. They claim they have registered the term "Compuseum" with the US Patent office.

    New for 2003

    Dec 2003

    The ZNODE 51 BBS One of the last of the pre-Internet BBS system, this page now is an archive site and also has some good links. Check their CD-ROM offer for classic software!

    July 2003

    links to CP/M related sites. is a human-edited site for "cataloging the Web", an "Open Directory". Check the site's home page for details.

    J.G.Harston BBC PD Library and files for Z80, 6502, CoPro, Tubes/Econet, SJ and so forth. Emulators also.

    April 2003

    Vintage Computer Collection of Eric S Klein. Variety of personal computers and some MITS Altair 8800's. Also discussion boards.

    Tonh den Hartog's Museum of "old" computer items: GEM for the IBM PC, CP/M, Z-80 Spectrum. [Link updated Feb 2011 tnks to Aart Schep.]

    John Elliott's homepagehas a section on CP/M including some useful descriptions and discussion of CP/M programming, and some interesting links.

    an AltairZ80 simulator by Peter Schorn, based on the SIMH emulator family.
    I have not looked at this, it was announced in comp.os.cpm. Purports to run various disk images from the Altair or from CP/M disks. With C source. As of 2006, he also includes a number of operating systems with source: CP/M in various versions, and modified versions of 8080 or Z80 "dos"es with a CP/M BIOS. Check it out!

    The "" site is gone, and so the "OAK CP/M" archive is gone. An Oakland University person said in a quoted email that they cannot afford to support their former archives. In April 2003 a German FTP site mirrorred the Oak CP/M archive. (Gone as of Jan 2006.) The corresponding Web site lists MS-DOS and UNIX archives but does not list CP/M archives. Nevertheless via FTP the link above "works" although it is slow. It appears that the archive is complete and mirrors what was on Oakland's site. If you go up a few levels to the "/pub" directory, there are archives for many other processors, programs and systems. Check some of the README's to see terms of use. It appears that most but not all of the Oakland CP/M archive is on the Walnut Creek CP/M CD-ROM; commerical items in the Oakland archive may not be on the Walnut Creek CD-ROM.

    Feb 2003

    "The following were posted in late Feb 2002 by George Czerw, on newsgroup comp.os.cpm. I can't vouch for all of these sites; when I visit them I'll change these to Web links." - Herb in 2003.

    Chaos Cottage BBS CP/M file listing from 1998. This was for Amstrad/PCW software but also CP/M software and Z-system.

    Gene Buckle's extensive Retrocomputing Archive of files and documents.

    The DiskDoctor CP/M Page, by 2008 a Web page about CP/M and PCW's (Amstrad).

    Jan 2003?

    an updated mirror of a hard drive tech reference from Michigan Tech, by Chris Hooper.

    Howard M Harte's Northstar site with docs and I think an on-line Northstar system!

    D Bit's 8-inch floppy disk adapter for 8-inch drives on PC\windows systems. Note: they don't provide PC software for CP/M diskettes, but they do have an MS-DOS utility for PDP-11 diskettes called "PUTR" that may be relevant. Check my S-100 FAQ for further discussion of 8-inch floppy drives and PC/Windows systems. As of Nov 2004, this adapter was still available from

    The Retro Computer Society of Rhode Island has quite a collection of mainframe and minicomputers; and they've been kind to me when I've visited and donated stuff. They WERE a very active group and they have monthly public presentations at their warehouse/museum.Their Web site and domain as of 2008suggests they are less active, after a major physical move within Providence RI.


    In June 2002 I corresponded with Steven Vagts, the long time editor of Z-100 Lifeline, a newsletter about the Z-100 and related Heath and Zenith products. He also has some business in Z-100 products. His LifeLines Web page,
    (still there in 2003, again in 2006, 2008) has a lot of useful Z-100 information and sometimes some products. In Aug 2019, he moved his Z-100 Lifeline to his own Web domain.

    In Feb 2002 I discovered the FreeGEM Web site in the UK for FreeGEM. That site said Caldera/Lineo in 1999 released Digital Research's GEM under the GPL license agreement. Since 2002 FreeGEM has developed further: there is a FreeGEM Web ring linking several sites. Check it for current developments. As for Caldera and Lineo, and the current status of DRI's CP/M, check my Digital Research CP/M Web page. I'll also put some FreeGEM Web links there.

    In March 2002 I corresponded with Jim Battle. He has an extensive Web site on the Processor Technology SOL including on line docs, software, emulators, even cassette tape files! A lot of effort, and I'm pleased to link to him. Note: he also has some NorthStar stuff as the Northstar floppy disk controller was the classic upgrade to the cassette-based Sol. NorthStar started out as a disk-upgrade company before they made their own S-100 system.

    2001 and earlier

    Note: in Jan 2006 I've removed links below that were duplicated above.

    Links as of Oct 2001:
    BBC Basic and other Z80 stuff by R. T. Russell
    As of 2009 Mr. Russell recommends use of this Web link.

    Links as of sometime in 2001:
    HeathKit company page, by William A. Wilkinson.

    The following list of CP/M software archives (Oct 2000) are courtesy of the CP/M FAQ:
    Update Computer club in Sweden has mostly old DEC stuff but that includes some Decmate CP/M software.
    UK site Demon Internet Service archives for many old OS's including CP/M Dead in Jan 2006

    The following archive listings are a result of a Google search and verification, October 2000:
    Seasip at CP/M site, no updates since 2005.'s archive of OS/2, MS-DOS and CP/M software among others.
    Southcom site, Australian, HAD quite a selection of CP/M files. Now it's just Linux.

    Digital Research archives: Lineo had some of these files (and DR-DOS) available via FTP since 1999, at their FTP site but no longer as of 2005. Their "terms of use" suggested then they were are available for non-commerical use and for licenced commercial use. There may be other stuff there.

    As of NOv 2014 there are verified all links below, removed or edited dead one, removed links already referenced above.

    New for October 2000:

    Classic computing . com site by David Greelish. Site comes and goes.
    Trailing Edge Web site of old computers is back in 2006. Has a lot of software resources.
    MESS site, a single emulator for various old computers, mostly gaming systems. [but see 2012 entry above]
    Logan Industries HAD updates of DRI multiuser DOS, a commercial product, on this site. In 2006 they just link to other sites with Web based products.

    As of July 2000:

    Tom Carlson's Obselete Computer Museum. includes list of many other old computer Web sites, show and tell about many old computers.
    As of 2006, he's apparently selling off his collection and "virtualizing" his museum.

    Multibus manufacturers group dead link as of 2006

    New for jan 2000:

    Mark Rison offers a Z80 assembler and TCP/IP source code for Amstrad on his page. [Gone as of 2008, but here's a related Web link, thanks to Allen Cobb.]

    New for July 1999:

    Roger Hanscom's (Dec 2014) "computer archeology" Site (may be called oldcpusrus) - Z80 stuff, early IBM stuff.
    Classic BASIC games page BASIC games to download.
    Tim Mann's TRS-80 site ,with related info on S-100 topics:

    New as of Nov 1998:

    Vintage Computer Festival in CA.
    MITS/Altair: the Virtual Altair Museum
    Yahoo! Altair Computer Club, chat area & msgs

    New for Sept 1998:

    The Retro-Computing Society of RI, Inc. mostly larger computers (mini's, mainframes). [See their current link in 2008 above.}

    Jim Willing's Computer Garage (now museum) and parts store was online. As of 2014, he makes appearances at Vintage Computer Festivals.

    Computer Museum of America (San Diego CA, USA) Home Page
    As of 2005 the collection was "gifted to a local university library". Their Aug 2005 newsletter mentions their "last hurrah" at Coleman College.

    Contact information:

    Herb Johnson
    New Jersey, USA
    To email @ me, see see my ordering Web page.

    Copyright © 2021 Herb Johnson