2048.COM

BIOS-interrupts based, 16-bit assembler written, power of 2 formed logical game.

Works under:

• DOSBox
• FreeDOS, MS-DOS (tested in QEMU with SeaBIOS)

Doesn't work on:

• NTVDM
• real PC (hey, don't laugh at me, you)

Based on 2048 originally written by Gabriele Cirulli. Licensed as WTFPL software. (C) AHOHNMYC, 2017

Compiling:

Tested with TASM 4.1 and TLINK 7.1.30.1

:: m - multiple passes
TASM /m 2048.ASM
:: t -  COM compilation
:: x - 'cause we do not want MAP file
TLINK /t /x 2048.OBJ

Bugs:

One, but fat and complex.

• Sometimes it doesn't work.

Game doesn't want to start correctly in XP's NTVDM and on my PC with real (and strange) BIOS.

I don't know what's wrong with NTVDM and how it interacts with physical BIOS (and exists those interactions at all or not).

In case of BIOS all is simple: some INTs returns changed registers. This behavior not described in my literature and available references (HelpPC 2.10 [1991], TECH Help! [1993]).

I see single simple solution: wrapper for all calls that'll pusha/popa every time. (I know, it's ANON.FM's level, but it have to work correctly)

Something like that:

int_wrapper	proc
	pusha
	; addressing crap
	; interruption call

	; maybe sort of self-alterating code for minimum complexity
	;'cause int call - 2 bytes: INT 20h == "CD 20" in hex codes
	; addressing, segment horror - DO NOT WANT.
	popa
	ret
int_wrapper	endp

Todo:

• More variability (maybe different phrases dependent on score)
• Try to compress code further (but I at present time done some scary things about reusing high registers and somewhere ignoring high-halfs at all)
• Some easter eggs