"Byte-01" CP/M code to BASIC code

[Gelip]

I want convert piece of code from CP/M file of "Byte01" computer to working in clone ZX Spectrum "Byte" BASIC. Program WW.COM after run in CP/M OS print on screen image and play music. I found image in WW.COM code in offset 2404. Sound data is probably in offset 1FB5 - 2403. Need help to disassemble code. I want to get something like in attach video file (AKDI.zip)
AKDI.zip
I try debug this file in CP/M 80 Emu with DDT.COM debugger:

D:\cpmemu>cpm z80 ddt ww.cpm
CP/M-86 emulator for DOS vers 1.3 - 11/30/97
Copyright (c) 1985, 1997 Jim Lopushinsky
Z80 CP/M-80 emulator for CP/M-86 vers 1.3 - 11/30/97
Copyright (c) 1985-1997 Jim Lopushinsky
DDT VERS 2.2
NEXT  PC
4100 0100
-l
  0100  JMP  1140
  0103  NOP
  0104  LDAX D
  0105  MOV  M,A
  0106  INX  D
  0107  INX  H
  0108  DCR  B
  0109  JNZ  0104
  010C  RET
  010D  MVI  C,00
  010F  MOV  M,C

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[jerri]

Gelip, you can use Ida interactive disassembler to disasm this

[Gelip]

Gelip, you can use Ida interactive disassembler to disasm this

Yes, right but i don't know how use this tool :-). Maybe anyone look at code?
Program WW.COM from disk image cpm_games2.kdi after change extension .kdi to .cpm possible mount in EMU 1.01 Robotron 1715 to Drive B: and open Debug window:

[jerri]

Gelip
here is ida database

[jerri]

Gelip, check it
the result is not guaranteed, but you can understand some routines.

[Gelip]

Thx. I also extract code with dZ80 2.0 (Z80 disassembler) :-). Problem is how interpret this code. I know that first instruction is JUMP to 1140 offset.

[jerri]

Thx. I also extract code with dZ80 2.0 (Z80 disassembler) :-). Problem is how interpret this code. I know that first instruction is JUMP to 1140 offset.

i make for you this file
analize it

[Gelip]

Is possible simply insert WW.COM 16384 bytes to RAM memory ZX Spectrum e.g. 40000 and run SUBROUTINE with RANDOMIZE USR 4+position code xxxx ??

I try like this:

1. In Spectaculator make new TAP file
2. SAVE "ww" CODE 40000,16384 (size WW.COM)
3. In ZX-Blockeditor insert WW.COM to block Standard Data file TAP
4. In Spectaculator open TAP and LOAD"" CODE
5. Now have all WW.COM in memory from address 40000
6. I calculate position offset subroutine and add this to 40000 e.g. 1F6B (8043 DEC): 40000 + 8043 = 48043
7. Next try run RANDOMIZE USR 48043

I try also before CLEAR 48042

Is this is possible without fix code address?

[jerri]

Gelip, nop
all program must work at #100

[Gelip]

For me disassembling is difficult :-(. Screen image I found in a simple and fast way - opens WW.COM in HEX editor :-)

Sound data is probably in offset 1FB5 - 2403 :-). This sound data is for play over chip VI53 in "Byte" or "Byte01" computer. This data have characteristic structure - every fourth position occurs 10 HEX.
Music begins with the notes: F D C A#:

| 10 46 36 00 | 10 43 33 00 | 10 41 31 00 | 10 3B 2B 00 |
|-------F-----|-------D-----|-------C-----|-------A#----|

This is User Manual of three-channel sound generator. The table shows that for one note need two numbers. HEX or DEC numbers do not match the table but the structure is preserved if the note F = 36
At end of sound data in offset 2372 is header: MESCA - maybe this is characteristic for some sound program made in 90's ?