BIOS and FORMAT for Versafloppy II

Here's correspondence from Bruce Jones for Nov-Dec 2003 on his BIOS, FORMAT, SYSGEN and BOOT programs for the SD Systems Versafloppy II card. He also has some configuration software and docs to help set these up. I've kept most of the email intact, so you can "look over his shoulder" and see his progress. The latest from Bruce will therefore be at the end of this document. But check my SD Systems page to obtain the actual software mentioned here and related software, and any SD Systems hardware I may have available.

For discussion of fast diskette read/writes at slow processor speeds, see his document on assembly language and the Versafloppy II, including notes on 8080 operation. For Bruce's work on the SD Systems VDB-8024 video card, follow the link. If you have questions or comments, email me and I will forward them accordingly.

This page last updated Dec 31 2003.

To return to my S-100 home page, follow this link. Material on this page (c) copyright Herb Johnson 2003, except for material provided by Bruce Jones with his permission, for which he retains copyright. Herb Johnson

[Nov 15 2003]

Hello Herb,

I have made three 'stand-alone' programs: VFORMAT.COM, VFSYSGEN.COM
[and] BOOTSTRP.COM. They could be used to allow you to quickly check out
the VF II BIOS and the Format program. Total bin size is 10K, 19K and 1K.

You could use them right away as follows.

Transfer them to any working CP/M system you may have with a
working Versafloppy (It could even be a second FDC, unused).

1 - run VFORMAT, and format a diskette.

2 - run VFSYSGEN to write the system tracks

Note, before running VFSYSGEN, you can [load it in DDT and patch any needed
console I/O routine under DDT. I have embedded the ASCII names of each
routine (CONSTAT, CONIN etc), and put in lots of NOPs for patching.
If not patched it is set up for
a VDB-8024. Patch area is just after 2600H in the image. I'll supply more
details if you want to try this.

3 - Run the boot strap. I'll put in a 10 second delay (at 4 mhz) so you can
remove your floppy from A: and install the sysgened diskette from B:.

If nothing else, you can check the format software & comment on it's
features and options.
You do not need a special BIOS to use it.

BTW, you can format 3.5" HD, 5.25" HD or 8" drives with it, and it
'sees' all of them as 8" drives.

[Nov 29 2003]
Hello Herb,

I've been fine-tuning the software to make implementation a breeze.
It is finally done now, and it will include a DOC file showing step by step
how to get it up and running.

If a person already has a working S-100 system, or an S-100 system with the
VF II as a second controller, then it should take, really, just minutes to
get it going.

The stand-alone sysgen takes 3 seconds to build the boot tracks.
The stand-alone format program will make a 1.3 mbyte compatible diskette in
under a minute.

I've also included better versions of the stand-alone bootstrap program,
useable if one does not have a boot ROM ready. You can format & sysgen drive
A or B, and boot from A or B as needed during the setup process.

Once booted the BIOS supports up to 4 drives, any size mix, so you can have
3.5" pairs and 8" pairs if needed, a configuration I often used 'till my
+24V supply died.

Utilities include a simple configurator, a disk to disk copy program and a
Norton-like disk doctor program for CP/M.

I've just checked using a 3.5" HD diskette in 8" SS-SD format and it works
great, so I/you can put the source and utilities on them for distribution.
I'll have notes on how well the 3.5" HD drives work with the VF II and why
they look like 8" drives for practicle purposes . BTW, I had similar results
with the 5.25" HD drives as well, they also work at SD, & DD formats OK.

I'll get all this off early next week.

Hope you don't find too many bugs. The basic code has been working since
1981, and no one has had trouble with it.

Best regards,
Bruce Jones


Dec 5 2003

Hello Herb,

I continued on testing all of the software and made dozens of changes, in
the form of 'safety features' to be sure that potential users do not run
into bad situations. So here is the package:

VFORMAT.ASM - the multi-featured formatter
VLOADER.ASM - the system track loader
VFSASG.ASM  - very high speed stand-alone sysgen program, sysgens in about
              under 1 second now
VFBOOTA.ASM - stand-alone boot strap for A, B, C or D drive, with A as
              time-out default
VFBOOTB.ASM - as above, but B as time-out default
VFSYSGEN.ASM - a 'standard' BIOS-aware Sysgen
VFCOPY.ASM  - disk to disk copy (backup, if you wish)

The above come with .COM or .HEX images, as needed, for people who want to
build custom systems.

Then, ready to patch and Sysgen images as follows:

CPM1720.COM - a 20K CPM
CPM2932.COM - a 32K CPM
CPM4548.COM - a 48K CPM
CPM6164.COM - a 64K CPM

(The first two digits are the MOVCPM factor, the last two the RAM top.)
The only patching is the easy to see area for console & keyboard I/O. It is
set for a VDB-8024 as shipped.

Also some DOC files to tell 'How To' do it all.

All the code wotks with a VF II or my Z3S FDC card. At startup it tests to
see what FDC card is plugged in, sets the operational bits and away it goes.
The sign-on messages even tell what it has found to work with.

I was bogged down with a few system problems from time to time, dirty S-100
contacts, bad batch of 3.5" diskettes etc.

Looks like Monday or so is the ship date.
I've run through many coding-test cycles to be sure users will have a tough
time getting into trouble. The code is about as easy and fool-proof as I can
make it for now... I have put in several 16 hour days since a few weeks
ago. I just don't want people getting on the 'phone' to me for support, or
having to pester you for replacement diskettes if something goes wrong.
Looks like that will be kept to a minimum now.


This first software is all Z80. I expect you or whoever makes the first try
at it to understand that. In addition it is written in the TDL ZASM Z80
dialect, and I'll include ZASM and a full manual (But you will not need it).
Later, when everything looks OK, I will convert to MAC (or even ASM when it
goes to 8080 code). I've put verbose comments in the VFBIOS and VFORMAT
source, so one can follow it with relative ease, should they wish to add I/O
devices or a new format type, etc.

Best regards,
Bruce Jones