Extremely simple (no expressions or macros) strict 3-column assembler for the Sharp SM510.
Mario's Binary Factory (mbf) is an extremely simple assembler for the Sharp SM510. It is a strictly 3-column assembler. Odd things will happen if your code breaks it's expected [LABEL] [OPCODE] [OPERAND] format (though a few corner cases involving comments are handled correctly).
It produces mame-compatible ROMs that are padded to 64 bytes per "page" and padded overall to 4096 bytes. I'm not sure of the format for the original ROMs but since these already account for the SM510's unique program counter order, conversion should be straight-forward.
- to assemble: Python 3
- to run the ROMs:
mameand the SVG overlay files from a suitable donor system that uses the SM510. - to build: haxe
This example assembles the test.asm program. In this example, we'll use "Mickey & Donald" as the donor system but any SM510 system that mame supports should work. Start by copying the needed zipfile (gnw_mickdon.zip in this case) to the same directory as mbf.py. Make sure to make a back-up of the zipfile as this process will replace the original ROM and keep only the overlay art.
python3 -m zipfile -e gnw_mickdon.zip .
python3 mbf.py test.asm dm-53_565
python3 -m zipfile -c gnw_mickdon.zip dm-53_565 gnw_mickdon_*
mame -rompath . gnw_mickdon
Note that I haven't found a way to launch original ROMs via the GUI. However, you can do so with the command line. If you launch the ROM directly from the command line as I've done here, you'll be given a chance to type "OK" and run despite the hash not being what mame expects.
The test ROM should work with any SM510-based system (not just "Mickey & Donald") for which overlay art is available and should flash every (non-bs) LCD segment all at once. The filenames of the ROM to replace and the SVG to include will change from system to system.
; Comments begin with ; and continue to the end of the line.
SKIP ; Comments should be able to follow any other content.
LOOP
EXC $0
T LOOP
or
LOOP EXC $0
T LOOP
FOO equ $2
LAX FOO
.word $0
Note that even though the CPU is 4-bit, the ROM-space is 8-bit and thus .word writes a full byte and not a nibble.
.org $DC0
ADD, ADD11, ADX, ATBP, ATFC, ATL, ATPL, ATR, BDC, CEND, COMA, DC, DECB, EXBLA, EXC, EXCD, EXCI, IDIV, INCB, KTA, LAX, LB, LBL, LDA, RC, RM, ROT, RTN0, RTN1, SBM, SC, SKIP, SM, T, TA0, TABL, TAL, TAM, TB, TC, TF1, TF4, TIS, TL, TM, TMI, TML, WR, WS
The assembler depends on a strict 3-column [LABEL] [OPCODE] [OPERAND] format. Even having trailing space (that doesn't lead into a comment) is likely to cause problems. If you're having trouble getting correct output, look for extraneous whitespace in your assembly. This includes "empty" lines (i.e. lines which just have a newline) which are interpreted as SKIPs. If you want an empty line, make ; its first character.
The assembler only understands hexadecimal numbers of the form $XXXX. It will handle shorter numbers appropriately. For example: $0045 is 69 but so is $45, $2 is 2, and so on. It doesn't do size checking. It's up to you to know if an operation can handle two bytes ($XXXX), a byte ($XX), a nibble ($X), 2-bits ($X <= 3), or a single bit ($X <= 1). You're always free to use leading zeroes regardless.
The mbf.py script is generated from Haxe source:
haxe build.hxml
Many thanks to Sean Riddle, Paul Robson, and hap. Their research has made homebrew LCD game development and emulation "practical".
Special thanks to everyone at the MAME project working hard to preserve handheld history as accurately as possible.