Yup, the code for the first ZUN Soft logo is now completely position-
independent and ready to be decompiled.
(Also, TIL that the PC-98 GRCG has hardware support for double-buffering
through page flipping. Heh, at least one feature that makes it a viable system
for games...)
From what I can tell, this program does exactly three things:
• preparing the initial high score list
• writing default settings to HUUMA.CFG
• and allocating the game's resident configuration structure and writing its
segment address to bytes 6-7 of HUUMA.CFG
All that results in a COM file of 6.84 KiB, 83% of which is library code.
That's why C was once seen as a bloated high-level language as well.
Thanks to the LOCALS directive, we do need to break compatibility to TASM at
one point after all. This is the rest we can reasonably change to get at least
through JWasm's first pass without errors while maintaining compatibility to
TASM.
Includes:
* the OPTION syntax to switch in and out of floating-point emulation mode
* REP CMPSB → REPE CMPSB
* Hacks for two 80-byte short jumps
* lack of support for floating-point stupidity ♥
as well as other issues that I covered in previous commits and overlooked in
some files.
From the TASM manual:
"NEAR labels defined with the colon directive (:) are considered block-scoped
if they are located inside a procedure, and you've selected a language
interfacing convention with the MODEL statement. However, these symbols are
not truly block-scoped; they can't be defined as anything other than a near
label elsewhere in the program."
MASM's own local label syntax - declaring labels using @@ and then jumping to
the next and previous @@ using @F and @B - is obviously too limiting for any
longer function, and is not even supported by TASM unless we switch it to MASM
mode completely.
While this is indeed ugly, it only affected 16 files, which is way less than
what we would get in a TASM build without LOCALS. In comparison to having a
modern, cross-platform assembler, that really is a small price to pay.
Really, Borland? You considered it necessary to add directives for object-
oriented programming (in Assembly!) and convenience features like bitfield
records or PUSHSTATE/POPSTATE, yet you never came up with the actually
*helpful* idea of just adding a simple basic pointer data type that depends
on the current memory model's data size?
Like, something like DP... oh wait, that's already taken, as an alias for
DF, the 48-bit 80386 far pointer type.
And this, exactly, is the problem with assemblers. The language itself is
undefined beyond the instructions themselves, but it's obviously very
uncomfortable to program anything with just that, so your assembler needs to
add custom directives on top of that, and of course everyone has different
ideas of the features and use cases that should (and should not) be covered by
syntax. (I'm looking especially at you, NASM.)
And then one of those developers sells their compiler division to a different
company, which then subsequently discontinues all products without ever
releasing the source code, trapping their nice extensions in a single
executable for a single platform that is not even legally available anymore.
tl;dr: http://xkcd.com/927/
(Damn, the other commit prepared for today is not getting done, why does IDA
have to be so terrible...!)
Anyway, here's a small consistency edit instead.
Once you've actually found the right syntax that makes the assembler just use
the default call type of the current memory model for both procedures (where
it's just "PROC" without anything else) and labels (where it's "LABEL PROC"),
these constants become completely unneccessary, even with TASM.
I guess this marks the final demystification of how segment declarations work
and how they are compiled. However, it only really makes sense for anything
outside the TEXT segment, like these floating-point functions. As long as the
slices aren't immediately next to each other, it would still be annoying to
have segment declarations inside of them, since we'd have to copy-paste these
declarations around every INCLUDE directive...
Finally - and there was indeed no way around switching to JWlink, as ALINK
v1.6 refuses to link the TH01 executables with a nondescript "Undefined base
seg" message once nec_fpinit.asm is included.
Mostly moving spurious null bytes, which are actually supposed to denote
alignment, into their associated slices, but also prettying up some of the
very first slices.
Well, we have to start reducing this mess somewhere. The actual reduced
initialization code I've been preparing still fails to compile, and the data
is shared with a number of other components anyway, so...
nmlgc