William D. Jones
@neauoire Fun DOS Fact For The Night (No Refunds If Not Fun):
DOS _does_ have a dynamic allocation call in its API, but what most apps do, including OpenWatcom C binaries _IIRC_, is "put in the EXE header to just reserve all available memory".
Meaning malloc/calloc is morally equivalent to "allocate from a fixed buffer on the user side".
William D. Jones
@neauoire Ahhh okay. And yea, I can't calloc 0x10000 for a DOS app. Idk if it's a DOS limit or libc limit.
My impression before tonight was "you can get 640kB if you do several 0x10000 byte allocations", but I need to examine further.
Related: Well, as long as you're okay at me working at my own pace (yes I know I'm slow getting back to you lately :P), I can look into such a file test.
I want answers from my libc first tho :P.
Devine Lu Linvega
@cr1901 the 0xff80 limit shouldn't impact drifblim
William D. Jones
@neauoire (DOS libc fread, open, opendir, etc wrap the DOS API provided by int 0x21.
The source code to my libc is on GH, so I can check what it does before and after calling the DOS API, but not convenient to do it right now :P.)
William D. Jones
@neauoire
Things I've learned about my DOS C compiler that I legitimately didn't know before starting this port:
1. calloc(65536, 1), or even calloc(65535, 1) doesn't work. I used calloc(0xff80, 1) as a workaround, but I will be changing that to a static 65536 array in PCUXN (DRIFBLIM crash?).
2. <dirent.h> => <direct.h>. No, I don't know either.
3. opendir() succeeds on files (the f***?!). I will need to replace with _dos_findfirst, etc.
William D. Jones
@neauoire Uncertain, as drifblim crashes DOSBOX right now :P.
Possible explanation follows in next toot.
William D. Jones
@neauoire Didn't think about that, but same result when I feed DRIF2.TAL with LF line endings.
But... DOS libc may be adding CR to LF when reading (although IIRC the DOS API never will do such bullshit). Not sure...
Devine Lu Linvega
@cr1901 It takes 40 seconds to assemble asma, if you use the drifblim rom, and assemble the drifblim tal file. How long does it take?
William D. Jones
@neauoire I don't have a VGA card attached to an old PC- only EGA and Hercules monochrome.
Okay, that's not quite right. I have a second IBM PC motherboard for hardware hacking and testing, and _that_ has a VGA card.
So I can at least try it to see how it works from real DOS.
Devine Lu Linvega
@cr1901 I still need to port a tiny change to the screen otherwise some of the example files will looks weird, but you could try this version I made for Turbo C.
Devine Lu Linvega
@cr1901 are you going to be using the screen device from the uxn-vga repo?
William D. Jones
One cool thing about the UXN DOS port, even tho it's taking me forever...
It's very much challenging assumptions I had about OpenWatcom. I will have to make a repo of test cases for diagnosing bugs later.
Speaking of which @neauoire, I have ASMA working in DOS. I think I want to iron out the libc bugs in PCUXN before I start testing on my IBM PC and PC AT, however.
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