Mysterious PC-DOS 1.10 Disk

[PorkyPiggy]

While browsing @geneb's Internet Archive uploads, I came across this weird copy of PC-DOS 1.10. It is weird because it came on an 8" disk, in CP/M format. Had that been the only anomaly, I might not have bothered mentioning it. However, what adds an extra layer of peculiarity is that it differs from the PC-DOS 1.10 available online.

I extracted the files out of it and compared them against the well-known copy of 1.10, 5 files (IBMDOS.COM, DEBUG.COM, DISKCOMP.COM, DISKCOPY.COM and FORMAT.COM) are different and it contains 2 extra files (GRAPHICS.COM and VENDOR-#.DY1). I'm not exactly sure what the differences are yet. Could it be a later (and maybe unreleased) version of PC-DOS 1.10?

I'm also curious why it's on an 8" CP/M disk. The files are in the exact same order as the official PC-DOS 1.10 release and the system files even have their attributes set.

The raw files from the 8" disk are in "dos_disk_files.zip" and a reconstructed bootable 5.25" 160K disk (with files truncated down to their actual sizes) is in "dos_disk_160k.zip".

Sincerely,
Pig

 

[retrogear]

CompuPro had an S100 PC compatibility card named PC-Video which could produce PC compatible graphics.
Oh boy, I have a real hardware CompuPro 8" setup but not that card. I can also image 8" disks on a PC. You gave me more to explore !!
I gotta keep watch on his archiving.

Larry G

 

[retrogear]

Here is the 8" disk image in simh emulation of CompuPro CPM-86. The disk itself won't boot. I think I have the PCBIOS source code for this.

 

[hmb]

CompuPro had an S100 PC compatibility card named PC-Video which could produce PC compatible graphics.
Oh boy, I have a real hardware CompuPro 8" setup but not that card. I can also image 8" disks on a PC. You gave me more to explore !!
I gotta keep watch on his archiving.

Larry G

CompuPro did not distribute their own version of PC-DOS for their systems(*). There was one (maybe two) two software companies independent of CompuPro that developed a version of PC-DOS along with the proprietary boot ROM necessary to boot their system on a CompuPro floppy drive system. One company called "Computer House" developed an MS-DOS version for the CompuPro called MS-PRO, and while copies of the disk image exist the boot ROM code seems to be forever lost. MS-PRO did not require a CGA/MDA compatible display like the CompuPro PC-Video board - it used standard character-based serial I/O, similar to Seattle Computer Product's 86-DOS releases. MS-PRO was distributed on 8" disks, but used FAT (not CP/M) formatting. Gerry Pournelle in his BYTE magazine ramblings mentioned his son had developed a PC-DOS port for his beloved CompuPro system, but I don't think that effort ever made it outside his own house.

As for the two disks "Pig" came across... Though the disk has a generic CompuPro label, the hand writing makes it clear this disk was not distributed by CompuPro itself. Looking at the contents of the files on those disks, there is no indication they were intended for use with any system other than an IBM PC but it is of course possible they are a pre-release PC-DOS 1.1. As for why these files are on an 8" CP/M format floppy - that may have been for no reason other than backup. In similar fashion, I have a pile of 8" CP/M format disks to which I backed up MSDOS system and application files years ago as well - odd yes, but it made sense given the much larger capacity of 8" vs 5" disks at the time.

(*) CompuPro did distribute DRI Concurrent DOS for their systems which could run some MSDOS software with or without their PC-Video board, but of course that is not PC-DOS or MS-DOS.

 

[retrogear]

I have Concurrent CP/M 3.1 with pc mode enabled like this simulation. It will run the linker on this disk. I've never seen an IBM copyright on my CompuPro before (that I can remember)

 

[Chuck(G)]

My recollection is that Bill Godbout and company initially balked at Microsoft's OEM pricing. So initially, they had a procedure where the client would purchase PC DOS and replace the IBMBIO.SYS file with Compupro's own version. In the early days of the IBM PC, it made a lot of sense.

 

[hmb]

I have Concurrent CP/M 3.1 with pc mode enabled like this simulation. It will run the linker on this disk. I've never seen an IBM copyright on my CompuPro before (that I can remember)
View attachment 1272803

Indeed... and strangely disconcerting

Your example shows that a fair number of PC/MS-DOS applications "at the time" would run under Concurrent CP/M, provided the app used only character-based I/O via the operating system, and did not write directly to video RAM.

 

[hmb]

My recollection is that Bill Godbout and company initially balked at Microsoft's OEM pricing. So initially, they had a procedure where the client would purchase PC DOS and replace the IBMBIO.SYS file with Compupro's own version. In the early days of the IBM PC, it made a lot of sense.

If so, a copy of CompuPro's version of the IBMBIO.SYS file would be an amazing find.
I am somewhat sceptical CompuPro was directly involved in this scheme. There was a fairly active CompuPro user group at the time that was not affiliated with CompuPro. I have a copy of their publication spanning a couple of years. Though the question of when CompuPro would provide MSDOS support came up frequently, there was never any mention of an "unofficial solution" like this.

 

[retrogear]

ok a light bulb just went on. these com files are not cpm80 they are x86 pc mode. Here's pc debug:

 

[Chuck(G)]

If so, a copy of CompuPro's version of the IBMBIO.SYS file would be an amazing find.
I am somewhat sceptical CompuPro was directly involved in this scheme. There was a fairly active CompuPro user group at the time that was not affiliated with CompuPro. I have a copy of their publication spanning a couple of years. Though the question of when CompuPro would provide MSDOS support came up frequently, there was never any mention of an "unofficial solution" like this.

I can report from memory that two of my acquaintances were die-hard CompuPro fans. Both reported using the PC-DOS hack--so it must have been common knowledge among some segment of the community. I wonder if the gang at Sorcim employed it--they had a lot of Godbout gear (I was offered one of the boxes and a VAX 11/730 when CA acquired them--I declined).