Take a look at disassembled code
From ST2205u wiki
Here are the relevant disassembled code fragments:
./insds.pl -b 0x4000 -s symbols.def fwimage-segX.bin >> fwX
7179- AD 7C 03 LDA $037C |-|.| 717C- C9 31 CMP #$31 |I1 | 717E- D0 09 BNE $7189 |P. | 7180- AD 7D 03 LDA $037D |-}.| 7183- C9 00 CMP #$00 |I. | 7185- D0 02 BNE $7189 |P. | 7187- 80 12 BRA $719B |.. |
71B7- A9 FF LDA #$FF |). | 71B9- A2 FF LDX #$FF |". | 71BB- 8D 7C 03 STA $037C |.|.| 71BE- 8E 7D 03 STX $037D |.}.|
707F- 48 PHA |H | 7080- A9 55 LDA #$55 |)U | 7082- 8D 40 02 STA $0240 |.@.| 7085- A9 53 LDA #$53 |)S | 7087- 8D 41 02 STA $0241 |.A.| 708A- A9 42 LDA #$42 |)B | 708C- 8D 42 02 STA $0242 |.B.| 708F- A9 53 LDA #$53 |)S |
7154- 9C 70 03 STZ $0370 |.p.| 7157- 9C 71 03 STZ $0371 |.q.| 715A- AD 16 02 LDA $0216 |-..| 715D- 9C 70 03 STZ $0370 |.p.| 7160- AD 17 02 LDA $0217 |-..| 7163- 8D 6F 03 STA $036F |.o.| 7166- 0E 6F 03 ASL $036F |.o.| 7169- 2E 70 03 ROL $0370 |.p.| 716C- 2E 71 03 ROL $0371 |.q.|
45FD- A9 2A LDA #$2A |)* | 45FF- 8D 00 80 STA $8000 |...| 4602- A9 00 LDA #$00 |). | 4604- 8D 00 C0 STA $C000 |..@| 4607- A9 02 LDA #$02 |). | 4609- 8D 00 C0 STA $C000 |..@| 460C- A9 00 LDA #$00 |). | 460E- 8D 00 C0 STA $C000 |..@| 4611- A9 81 LDA #$81 |). | 4613- 8D 00 C0 STA $C000 |..@| 4616- A9 2B LDA #$2B |)+ | 4618- 8D 00 80 STA $8000 |...|
