In mid-June 2010 I recieved a SWTP 6800 system from Bruce J. Black: some notes from him are included below. What I got is described below. In July I cleaned up the 6800 system, and powered up the dual floppy-drive portion. This page last updated Mar 26 2013, (c) Herb Johnson all rights reserved; quotes are copyrighted by the person quoted. - Herb Johnson
SWTP 6800 system cabinet with:
Bruce describes some of these cards, as below.
SWTP MF-68 dual drive cabinet with two Wangco model 82 5.25-inch drives
Loose boards included a MP-A2 CPU board; MP-S serial; and unpopulated wirewrap board, bus only wired up. Bruce says "I thought the unfinished card had a UART chip installed, but then I couldn't figure out why all the chips!"
...and two boxes 5.25" diskettes
black binder #1: Flex 1.0 1978, BASIC 3.0 1978, MiniFLEX 1.0 1978
ROM monitor 1.0 1977, various utility program descriptions
black binder #2: TSC 6800 Text Editing Sysetm SL68-24, TSC 6800 Text Processing Sysetm SL68-29d,
Black binder #3; hardware documents:
Notebook #2: TSC Space Voyage (text-based Star Trek game), source listing in 6800 assembler
Notebook #3: MP-P documents, 6800 co-resident assember docs, 8K BASIC ver 2.0 from SWTP, Motorola MkBUG documents
Also provided: a Seimens FDD 100-8d 8-inch floppy drive, 3rd party box (Floppy Disc Services); with FDD 100-8 introduction manual and maintenance manual
Check this Web page for details of the 6800 system by board, and some cleanup.
Bruce contacted me and said, among other things: "I also have my original SWTPC M6800 computer with a galloping 24 k of memory. It has a dual floppy drive attached. I think they had a 72k capacity. It's gotta go too. Don't know if it still works. It was my first. Somewhere I think the manuals and disks are around I used to use a model 43 teletype as a terminal. Like the floppy drives it was expensive." We corresponded and I obtained the system. Here's a bit of Bruce's history with it - Herb Johnson
"...I decided to start cleaning out the garage and found the documentation. The disks I found in a pile in the house. The system has 24K of memory, two floppy drives, a Kansas City cassette interface, and I think an EEPROM programmer. The original KC tapes are long since gone. The KC interface is homemade, but a schematic is included. There are also some websites dedicated to this stuff and I think they may have additional backups and data on this system."
The wire wrap [in the computer] is the KC card. There is a schematic for it on a hand drawn sheet of sketch vellum. I may have used a drawing template for the logic symbols. The cards in the chassis are for the serial control port, the floppy controller, and an EEPROM programming card. I think the serial card is wired to the KC card also. I made pictures and it looks like a second serial card is installed."
"The TV typewriter is another story!" Bruce describes it below.
A little personal history by Bruce M. Black
"In 1972 I decided to hang it up on law school and stick with what I do best, engineering. I interviewed for work with two companies and took the best job offer. Four years later they decided to dispense with my services for the usual reason, no work. I approached the other company again for a job and they said that If I didn't mind few trips out of town to support a contract they had with the Naval Academy I could have a job. I agreed and two years later those few trips turned into almost a year in Annapolis MD." Bruce added later: "Just for info I graduated U of Florida in '64 with a BEE degree. Bachelor of Electrical Engineering". Later I think it became the more standard BSEE. Spent most of my career designing controls for tracking systems to track missiles and aircraft or whatever."
"[In 1976] I thought the MITS Altair  too pricey for me. I liked the instruction set of the 6800 better, and the SWTP machine came in board sized kits which was fine by me. So for a while, about every trip to Annapolis a kit went with me. Nights in the Motel were spent building each board kit until I had the computer together that you now have. I thought I was a big man on campus when I reached a total of 24k of memory."
"Somewhere about the time the "build" [of my 6800 system] was going on Radio Electronics magazine published the TV Typewriter article. A technician friend and I teamed together to build the beast. He was into photography and made pictures of the PC board layouts. [PC boards can be made using photo negatives and photosensitive resist, and ferric chloride to etch out the copper outside the resist. - Herb]
"These things were huge, about 12" by 15" inches or so. He etched about 3 or 4 of them. They were not clean etches so we selected the two best boards and started construction. The boards required some cuts and jumpers to fix the poor etching. I also added some extra circuitry for interfacing and maybe some extra memory. I had also acquired a keyboard made by TI."
"The whole thing was put in a chassis and covered with mahogany vinyl. I made a slopping wood frame for the keyboard and bolted it to the chassis. We used a 12" Zenith TV for the display. This set was modified with an input selector switch and coax connector. You could either watch TV or have a 40 character by 16 line display."
"Later this was replaced by a Teletype Model 43 teletype which gave me both a data entry method and a printout. The Zenith TV eventually was used as such by my son until it died. The Teletype gathered dust until I trashed it many years ago."
"Computer number two was a Kaypro 10. It had a 10 meg hard drive. Two weeks after the warranty was up the drive died and it cost me $600.00 to replace it. Number three was hand-built so I could do my hardware thing. After that it was mostly home assembled PC's running MS-DOS until the Microsoft Windows switch, which once again denied me hardware access. So then I became a Linux fan where I could write hardware drivers and screw the computer up to my hearts content. I fired the Kaypro up about six months ago and it worked though it did produce a curl of smoke. I did an orderly shut down. I suspect a cap failed in a non-destructive manner. One of these days....."
- Bruce J. Black
In March 2013 I restored a Motorola MEK6800D2 board to operation.
swtpc.com's Web pages for the SWTPC 6800 and 6809 systems by Michael Holley. I see the site was last edited in mid-2006. That's four years ago from the start of this Web page. - Herb
I took some time in Nov 2011, to revive William Colley's 6800 cross assembler A68. It was written in C by William Colley and submitted by him to the old "C User's Group. Here's a ZIP file of my edited version of Colley's A68 cross assembler. Its compiled for 32-bit Windows in MS-DOS mode, using the lcc-32 C cross compiler which is freely available. To use it as a full Windows program, you have to recompile it or "wrap" it in some GUI. To use it as a 16-bit MS-DOS program, you have to recompile it in, for instance, Borland Turbo C 1.5 for MS-DOS. I've done similar work with Colley's A18 cross assembler for the RCA 1802, which you can find at this linked Web page. - Herb Johnson
In the fall of 2011, I corresponded with Martin Eberhard, another 6800 system owner. He has a number of MITS "Altair 680" systems. MITS created what became the S-100 bus with their Altair 8800 with the Intel 8080 processor. They are less-well known for their Altair 680. I created a Web page from Martin's correspondence about his work on restoring his Altair 680 system and some software he wrote to support it. [I do not have a MITS 680 system.] - Herb Johnson
I have some correspondence with Frédéric Le Duigou in France. He has a number of Motorola-based vintage systems. Here's a Web page I made in Jan 2013 about his SWTPC 6800 and his collection.
Copyright © 2013 Herb Johnson