3 ms·
> this is a machine with a clock ticking in microseconds. I can't imagine it'd take more than a week or so to reimplement any sort of business logic it had. Yo
by beachy 2y ago
> this is a machine with a clock ticking in microseconds. I can't imagine it'd take more than a week or so to reimplement any sort of business logic it had.
You're kidding right? In the old days people had to do insane things with their code to make it run fast enough. I'm thinking for example of programmers working with then-slow disk and drum storage who had to play elaborate timing tricks with their code based on when they expected data on the disk to rotate into position under the read heads. Just a few lines of assembler code, "ticking in microseconds", could conceal a terrifyingly fragile concoction of code. You could spend hours or days trying to understand it before you would dare to make a change.
Sure if you had an accurate, up to date, human-readable description of the system's "business logic" you'd be off to a flying start to migrate it to a new platform.
But the inalienable truth of old mainframe systems is that such a description no longer exists, if it ever did. The system itself - in COBOL, assembler or whatever - is the true description of the business logic. That's why IBM still sells mainframes compatible with their ancestors from over half a century ago. No-one dares to change many of these systems.
- russellbeattie 2y agoOK. You're right, "weeks" was a severe understatement. But we're talking about 30 years and CompuServe wasn't a bank or nuclear power plant or anything. Extracting the business logic should have been a project that was done and gone by the 2000s.
- euroderf 2y agoThis makes me think of that algorithmic black box that the IRS has. It is spoken of in reverent tones tinged with dread. I wonder if anyone's tried to throw an AI at it yet to figure out what the heck is really going on in it? And maybe decompile it to render it amenable to modification and recompilation.
- Bluecobra 2y agoIt might be easier for DOGE to just close shop and implement a flat tax than try to untangle that ball of wall of wax...
- Bluecobra 2y ago> I'm thinking for example of programmers working with then-slow disk and drum storage who had to play elaborate timing tricks with their code based on when they expected data on the disk to rotate into position under the read heads. There was an epic story I once read that revolved around this and it’s going to drive me crazy until I find it. Edit: Found it! It’s from “The Story of Mel, a Real Programmer”: > Mel never wrote time-delay loops, either, even when the balky Flexowriter required a delay between output characters to work right. He just located instructions on the drum so each successive one was just past the read head when it was needed; the drum had to execute another complete revolution to find the next instruction. https://users.cs.utah.edu/~elb/folklore/mel.html https://users.cs.utah.edu/~elb/folklore/mel.html