Microsoft Open-Sources 'Earliest DOS Source Code Discovered To Date' (arstechnica.com) 24
An anonymous reader quotes a report from Ars Technica: Several times in the last couple of decades, Microsoft has released source code for the original MS-DOS operating system that kicked off its decades-long dominance of consumer PCs. This week, the company has reached further back than ever, releasing "the earliest DOS source code discovered to date" along with other documentation and notes from its developer.
Today's source release is so old that it predates the MS-DOS branding, and it includes "sources to the 86-DOS 1.00 kernel, several development snapshots of the PC-DOS 1.00 kernel, and some well-known utilities such as CHKDSK," write Microsoft's Stacey Haffner and Scott Hanselman in their co-authored post about the release. [...] This source code is old enough that it hadn't been stored digitally. "A dedicated team of historians and preservationists led by Yufeng Gao and Rich Cini," calling itself the "DOS Disassembly Group," painstakingly transcribed and scanned in code from paper printouts provided by Paterson. This process was made even more difficult because modern OCR software struggled with the quality of the decades-old printout.
Today's source release is so old that it predates the MS-DOS branding, and it includes "sources to the 86-DOS 1.00 kernel, several development snapshots of the PC-DOS 1.00 kernel, and some well-known utilities such as CHKDSK," write Microsoft's Stacey Haffner and Scott Hanselman in their co-authored post about the release. [...] This source code is old enough that it hadn't been stored digitally. "A dedicated team of historians and preservationists led by Yufeng Gao and Rich Cini," calling itself the "DOS Disassembly Group," painstakingly transcribed and scanned in code from paper printouts provided by Paterson. This process was made even more difficult because modern OCR software struggled with the quality of the decades-old printout.
OCR struggled? (Score:2)
I'm amazed we can OCR in Egyptian scrolls on papyrus, but struggle with 30 year old green-bar printouts?
Re:OCR struggled? (Score:4, Informative)
Re:OCR struggled? (Score:5, Interesting)
The PGP encryption source code was printed in a loose-leaf book with checksums on each line to make it easy to OCR.
It was still a huge project because they forgot to convert tabs to spaces (or vice-versa) before printing so software had to be written to try all possible combinations of tabs and spaces on lines where the checksum check failed.
For the Apollo Guidance Computer code they got lucky and had a binary dump of the compiled executable at the end of the listing so they could run the OCR-ed code through the compiler and check for mismatches in the compiled binary to find the OCR errors.
It's definitely non-trivial and can be even if the developers went out of their way to try to make it easy.
Re: (Score:2)
It's so old... (Score:2)
... that all internal self-references say "86-DOS", and it displays "Seattle Computer Products" on the boot screen.
But yeah, let's pretend Microsoft created it.
Re:It's so old... (Score:5, Informative)
Well;, it's well known that after IBM failed to get an NDA with Digital Research for CP/M-86, they went to Microsoft and asked if they could supply the operating system. Bill Gates agreed and then they purchased a full license of 86-DOS from Seattle Computer Products.
They mildly patched it to get it working on the IBM PC (it was originally designed for SCP's 8086-based computer).
Note the source code actually existed - the Computer History Museum actually has it as a digital artifact. The only problem was it wasn't open source - it's was until now only available as a source-available license for studying and curiosity. What Microsoft did now was put it under MIT license so it's under a fully open open-source license that lets you compile and build it.
Also, Microsoft paid for a per-customer license for 86-DOS, paying $90,000 for it. The did this knowing they only had one customer - IBM. Eventually they hired the programmer of 86-DOS.
MS-DOS 1.0 wasn't particularly interesting other than appearing like an independently created version of CP/M. MS-DOS 2.0 added additional services that made MS-DOS look a lot more like an operating system - instead of CP/M opening the files for you (and passing their handle in your process control block), MS-DOS 2 let you actually open a file by calling an open function. (MS-DOS 2.0 inherited a lot of semantics from Xenix).
Denial of service? (Score:2)
And here I thought we were getting the code for the oldest denial of service attack known. I'm not sure anyone really cares about old versions of DOS.
Re: (Score:2)
And here I thought we were getting the code for the oldest denial of service attack known. I'm not sure anyone really cares about old versions of DOS.
I thought the exact same thing. Neither of us were entirely wrong.
Re: (Score:3)
yufeng Gao and Ric Cini (Score:2)
This isn't the Kernighan and Ritchie we're looking for; move along
Whoa (Score:2)
Does this signal a change in Microsoft's strategy of releasing bad operating systems?
They were going to open source (Score:4, Funny)
Historical (Score:3)
I wonder why Microsoft does not release more relevant code as Open Source such as Windows XP
Re: Historical (Score:3)
Maybe too embarassing?
Re: Historical (Score:4, Insightful)
Probably contains bugs for things theyâ(TM)re still including in recent versions of Windows.
Re: (Score:2)
Re: Historical (Score:2)
Re: (Score:2)
Because all versions of Windows after XP are just slopped on top of it. Release XP's code and the slop house falls.
I'm sure ... (Score:2)
it hadn't been stored digitally.
... that there's a Zip disc [slashdot.org] sitting around somewhere.
So... (Score:2)
Lol (Score:1)
Re: (Score:2)
Nah, everybody will be too busy watching the latest hit movie, "Ass"