MS-DOS 1.25 (Commodore CBM B Series OEM)
1983 by Commodore
For Commodore CBM B Series computers

This is a port of MS-DOS 1.25 for the CBM B Series computer with an
8088 co-processor board. This port of DOS never made it to
production.  This archive contains one 520k disk image (2083 256 byte
sectors) in ".d80" format. Note that this is a non-standard disk
format, and this software will not work with IBM PCs or emulators.
See the included instructions on how to make a disk image.  Source:
http://vintagecomputer.net/commodore/8088%5Fco%2Dprocessor/MSDOS1.25/
More info:
http://cbm-hackers.2304266.n4.nabble.com/CBM-B-Series-MS-DOS-1-25-Available-td4070031.html

--------

MS DOS 1.25 was sent to Commodore for use with their B Series systems with
a 8088 co-processor board.  It never made it into production.

There were few if any systems sold with the co-processor board, but a few
do exist, including the one in my possession.  I don't know how many copies
of the MS DOS for CBM exist, but I wouldn't forgive myself if I lost the
only copy!  I got it from the former president of CBUG.

I have found a way to migrate a copy of the OEM MS DOS to here it is:

http://vintagecomputer.net/commodore/8088_co-processor/

If anyone has a Commodore B with an 8088 co-processor download this file
and let me know if it works. (Or just contact me for a disk copy)

I have also uploaded some useful programs I use for any B series with an
8050 or SFD-1001 drive attached:

http://vintagecomputer.net/commodore/b128/

Here's how I would restore, you'll doubtless have different hardware, but...

1. Download the files to a formatted to 720K IBM diskette
BOOTMS.PRG
MSDOS.PRG

If they get renamed along the way remember these original file names

2. Boot a C64 and two 1581 drives, and load WCOPY+ by CMD. Copy the files
from the IBM-format 720K disk to a Commodore-formatted disk. I happen to
have set one 1581 drive to = 8, the other = 10. (9 is a 1571 drive)

3. Disconnect the 1581 assigned to drive 8 and turn off the computer

4. Attach a serial to IEEE converter and hook up an 8050 drive as drive 8.

5. Use WCOPY+ to move the files from the disk created in step 2 above to an
8050-formatted disk in drive 8,0 on the 8050 drive (or use an SFD-1001)

to format a disk: header "msdos",d0,i01 [enter]

6. Disconnect the 8050 from the C64, and attach to the CBM 128-80X or CBM 256X.

load "BOOTMS",8,0

If it works, you'll get a DOS prompt...on a Commodore! You can do very
little with this DOS, it's just a demo version. Note from the link above,
there are pictures of the boot screen.

-Bill
