Related ongoing thread:
Microsoft's 6502 BASIC is now Open Source (2025) - https://news.ycombinator.com/item?id=48257058
Microsoft open-sources “the earliest DOS source code discovered to date”
121–130 of 218 posts
Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#122Earlier quoted context omitted.
I'd like to hear more about what works in OCR of dot-matrix fonts. I've been able to OCR letter-quality printer output to 97% (mostly Os and Xs problems). But it seems that machine-learning text-recognition is also now biased to reject computer code because it doesn't look like human language.
There's a writeup here from one of the people on the team about the work it took to go from the listings to source code. http://cini.classiccmp.org/recoveryblog.htm > With less-than-satisfactory OCR output, I resorted to a process I used many years ago when converting scans made of old Commodore ROM dumps printed on a Commodore 1515 dot-matrix printer. The process relies on the ASCII OCR output having the same repeti…
Hmm, doesn't say anything about what OCR tools they used.
I've got a 4" stack of wide-carriage COBOL. I guess it's two revisions of the same system so I only need to scan the newer half. Its probably from a TI Omni 810.
On the other hand, I've got 100 pages of code printed in compressed font by someone wanting to make sure that 80+ char lines fit within margins. So a lot of words just don't come out at all. A frequent error is "A" becomes "H", "O" becomes "U" because the top dots aren't "attached".
And columns of line numbers starting with 0001, or hex? The most confounding thing is OCR that thinks 00 is a sideways 8, and that dominates the uniform block, so it tries to interpret the whole column as sideways text. In another situation, it interprets two stacked lines (each starting with 0) as one line starting with 8 and it just goes off the rails.
So I've been working with automatic skew correction, then clipping it into rows, in order to get each line of text isolated from the surrounding context. When I do that, I get better results, but it is not great either.
I'm considering going all-in on training a new recognizer on snippets. For that, I'll be constructing "The Set of All As" and so on.
Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#123Earlier quoted context omitted.
> unless they used punch cards For MS-DOS?
Not likely. Punch cards disappeared around the end of 1976.
My firt job out of college in the early 1990s was at an equipment manufacturer who was still using them. They had a big chart on the wall titled "punch-card elimination" and a line trending down, but it wasn't at zero yet.
My work there was all new code and didn't involve any of that, however.
Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#124At some point, we'll probably have a new field in history for digital archeology , and I'm really envious for those future historians! They'll be getting to sleuth around old datasets, trying to reconstruct the history of computing, understand long-forgotten file formats to preserve data, use statistical methods to analyse binary backups, and trace for specific documentation versions to crack old encryption formats..…
This field already is alive and well in the gaming community. Games companies are notorious for not spending money on keeping their old code around, which is why it's been at the forefront of digital archaeology efforts a lot of the time to preserve the industry's history.
I'd also throw the wayback when machine and the internet archive into this bucket.
Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#125It is rare that I say this but, thanks MS! Arguably just as, if not more, important is the BASIC that they wrote. That was what they actually wanted to do. DOS just got them the contract with IBM. For decades MS was really a developer tools company with a side biz of writing operating systems and other misc software. They also open sourced that BASIC code too [1]. [1] https://opensource.microsoft.com/blog/2025/09/03/…
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Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#126It is rare that I say this but, thanks MS! Arguably just as, if not more, important is the BASIC that they wrote. That was what they actually wanted to do. DOS just got them the contract with IBM. For decades MS was really a developer tools company with a side biz of writing operating systems and other misc software. They also open sourced that BASIC code too [1]. [1] https://opensource.microsoft.com/blog/2025/09/03/…
I dont think I've ever seen a commit that says "49 years ago". Damn.
Not quite as old, but brl-cad is still in active development and has commits from 1983. https://github.com/BRL-CAD/brlcad/graphs/contributors?all=1
Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#127THANK YOU!
Can we now have all the Infocom games owned by Activision (which is yours) now? Pretty please? I know the source is available, but we'd like them with a MIT license (including the manuals, artwork etc).
PS: a couple of them could be harder, like Shogun, but it's okay to skip these.
Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#128Earlier quoted context omitted.
I'd like to hear more about what works in OCR of dot-matrix fonts. I've been able to OCR letter-quality printer output to 97% (mostly Os and Xs problems). But it seems that machine-learning text-recognition is also now biased to reject computer code because it doesn't look like human language.
There's a writeup here from one of the people on the team about the work it took to go from the listings to source code. http://cini.classiccmp.org/recoveryblog.htm > With less-than-satisfactory OCR output, I resorted to a process I used many years ago when converting scans made of old Commodore ROM dumps printed on a Commodore 1515 dot-matrix printer. The process relies on the ASCII OCR output having the same repeti…
Pretty interesting. I wonder if a whitelist against certain columns in the output could help, e.g. this column can only contain valid x86 instructions (e.g. MOV is allowed, M0V is not), this column can only contain hexadecimal (1 is allowed but never "l"), etc. Probably more work than it's worth given the final line-by-line comparison that happens anyway.
Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#129It is rare that I say this but, thanks MS! Arguably just as, if not more, important is the BASIC that they wrote. That was what they actually wanted to do. DOS just got them the contract with IBM. For decades MS was really a developer tools company with a side biz of writing operating systems and other misc software. They also open sourced that BASIC code too [1]. [1] https://opensource.microsoft.com/blog/2025/09/03/…
What's interesting is that Microsoft BASIC itself was derived from BASIC-PLUS which itself was derived from Dartmouth BASIC (which evolved into a structured programming language called SBASIC (Structured BASIC). But the popularity of Microsoft BASIC, actually halted the standardisation of SBASIC as an ANSI standard. https://en.wikipedia.org/wiki/Microsoft_BASIC The Altair BASIC interpreter was developed by Microsoft…
Nit: the pdp-10 is generally considered a mainframe not a minicomputer.
Re: Microsoft open-sources “the earliest DOS source code discovered to date”
#130Earlier quoted context omitted.
> writing a few thousand lines of assembly was what it took to launch a successful software company. Yes, but that assembly was not DOS, and it wasn’t easy. Microsoft purchased the DOS code, they didn’t write it. Of course, they did develop and modify DOS. But that was a clever (and lucky) business deal, not a technological accomplishment. The real beginning of Microsoft was earlier, with Allen, Gates and Davidoff wr…
Imagine if the University had sued for their share of the IP and that was created using their resources… It’s funny because I thought Jobs/Wozinak got their initial funding from selling phreaking boxes. And more recently, Anthropic engaged in criminal copyright violations with only a slap on the wrist. Feels like a common theme of every “great” company having its origins from a “boost” resulting from criminal activit…
See also Airbnb and Uber.