DOS ain't dead

targeting Windows 1.0 console (Developers)

posted by kerravon , Sydney, Free World South, 30.04.2025, 15:11

So I already "know" that the Win16 environment didn't allow you to write console mode apps like Win32 does.

And I already know that Watcom and others worked around that issue by opening a graphics window in their C library for writing to stdout.

PDPCLIB doesn't currently have Win16 as a target, and indeed, I never really programmed under Win16 because without a console I'm not very interested.

I now believe I have a simple workaround that I would have been happy to use if I had thought of it earlier and had started PDPCLIB earlier.

What I can do is treat Win16 as a batch system, and the C library can simply open a w16stdin.txt, w16stdout.txt and w16stderr.txt.

That would have given me a lot of memory for some tasks both then and now. ie I could make that executable work today with the x64 CM16 work. Even if I had lost the source. I assume they made most of the LDT available, giving me around 256 MiB. Possibly double that depending on what they (or I) did with the LDT. ie do they allow a huge malloc and create code aliases for all the entries? OS/2 1.0 doesn't allow that - I have to do individual 64k allocs if I want to create a cs alias.

Anyway, sniffing around, it looks like Windows 1.0 provided a KERNEL.DLL with functions OpenFile. I don't see a WriteFile. I think C library authors were maybe meant to use _lwrite, but in that case, why not use _lopen too? What is OpenFile for?

Anyway, with the batch system in place, would it have then been possible to optionally install a TSR to intercept DOS opening those particular filenames and redirecting them to some other place (like the original console window or a new black screen if the original is inaccessible?).

And then fast forward 40 years from 1985 to 2025, and instead of a TSR, I simply get my x64 CM16 pseudobios to recognize opens of those "standard names" and write them out normally, so it is no longer (if it ever was) "batch only".

If all this is technically possible, any suggestions on the "standard names" instead of w16stdin.txt etc?

Complete thread:

• targeting Windows 1.0 console - kerravon, 30.04.2025, 15:11 (Developers)
  • targeting Windows 1.0 console - kerravon, 30.04.2025, 18:13