Back in the days of Continental Software, there was a BASIC program which displayed the Continental Software logo, and then loaded a game, which immediately followed it. The game was a chunk of assembler, intented to run at an address above 04000H (probably 04100H, but I forget).
This package includes Loader.mtx,
which does something similar, for .COM files
(assembled to run at 00100H), and without the logo.
It should be good for files upto 46KB or so.
Using Paul Daniels mtx2bas program,
we can see how it does it :-
$ mtx2bas Loader.mtx mtx2bas v0.4. Options: . File Loader.mtx. MTX Filename: Loader STKLIM: 0xF8F2. SYSTOP: 0xFB4B. Basic: 10 GOSUB 30 20 ASSEM CODE 0x400F 31 00 F8 LD SP,#F800 0x4012 AF XOR A,A 0x4013 32 D2 FA LD (#FAD2),A 0x4016 D3 00 OUT A,(#0) 0x4018 3C INC A 0x4019 32 68 FD LD (#FD68),A 0x401C 21 80 40 LD HL,#4080 0x401F 11 0E 00 LD DE,#E 0x4022 CD AE 0A CALL #AAE 0x4025 21 00 41 LD HL,#4100 0x4028 ED 5B 8C 40 LD DE,(#408C) 0x402C D5 PUSH DE 0x402D CD AE 0A CALL #AAE 0x4030 F3 DI 0x4031 21 41 40 LD HL,COPY 0x4034 11 00 F8 LD DE,#F800 0x4037 01 0E 00 LD BC,#E 0x403A ED B0 LDIR 0x403C 3E 80 LD A,#80 0x403E C3 00 F8 JP #F800 0x4041 D3 00 COPY: OUT A,(#0) 0x4043 21 00 41 LD HL,#4100 0x4046 11 00 01 LD DE,#0100 0x4049 C1 POP BC 0x404A ED B0 LDIR 0x404C C3 00 01 JP #100 0x404F C9 RET Symbols: COPY 4041 30 VS 4:INK 12:PAPER 1:COLOUR 4,1:CLS 40 CSR 2,20:PRINT "Please wait, Program LOADing" 100 RETURN 1000 SAVE "Loader":RUN
Back in the days of Continental Software, there was a program called
CSAVE.COM.
It would be used to save the chunk of assembler in Memotech tape format.
It would save a 14 byte header comprised of
0xaa 8 bytes filename 3 bytes extension 2 byte length
This was then followed by the file content.
If you have a game in CP/M .COM file format,
you should be able to use the COM2mtx.sh in this package
to prepend Loader.mtx to make an .mtx file for it.
It writes the game content in the same format that CSAVE.COM did.
eg: assuming you start with SMG.COM (36KB)
$ ./COM2mtx.sh SMG $ memu -s -v SMG.mtx LOAD ""
Note that the game must not assume anything about the initial state of
the system, such as interrupts being disabled, or not configured at
the CTC.
ALPHA.COM is an example of a game that fails because it
assumes the CTC is not configured.
COM2MTX can be downloaded from
http://www.nyangau.org/com2mtx/com2mtx.zip.
Copying of this program is encouraged, as it is fully public domain. Even the source code is included in the package. It was created on the authors time and equipment. Caveat Emptor.
The author of COM2MTX and this documentation is Andy Key
(email andy.z.key@googlemail.com).
{{{ Andy