Omegamatrix Posted June 28, 2009 Share Posted June 28, 2009 Here is the checksum from the demo, and the checksum from Bachelor Party side by side. After accounting for the different registers that are used then they are almost exactly the same routine. DEMO BACHELOR PARTY lda #$30 lda #$30 sta romHigh sta romHigh lda #0 sta checksumVal ; the demo reclears these sta romLow .loop: .loop: ldy #0 ldy #0 lda (romAddress),Y lda (romAddress),Y clc clc adc checksumVal adc checksumVal sta checksumVal sta checksumVal inc romLow inc romLow bne .loop bne .loop sec sec lda #0 lda #0 adc romHigh adc romHigh sta romHigh sta romHigh cmp #$40 cmp #$40 bne .loop bne .loop lda CHECKSUM_VALUE lda CHECKSUM_VALUE cmp checksumVal cmp checksumVal bne .crash bne .crash rts rts .crash: .crash: lda #$F1 lda #9 ; different audio value sta AUDC0 sta AUDC0 sta AUDF0 sta AUDF0 sta AUDV0 sta AUDV0 jmp ($3FFE) jmp ($3FFE) The difference though is Bachelor Party does use a origin of $3000, and the demo uses $F000. From what I saw this was the only bit of code in the demo that used $3000 as an origin. So it seems it came from Bachelor Party. I did a search through all the Mystique/Playaround roms for 60,FE,3F in HOM3, which translates into jmp ($3FFE). Bachelor Party was the only hit. The checksum routine is in both the Mystique and Playaround versions of Bachleor Party, as well as the Demo of course. Quote Link to comment Share on other sites More sharing options...
Godzilla Posted June 29, 2009 Share Posted June 29, 2009 Wow, thats awesome, thanks for sharing, JG Quote Link to comment Share on other sites More sharing options...
Wickeycolumbus Posted July 3, 2009 Share Posted July 3, 2009 I thought some of you may be interested in this, here is what the Mystique logo looks like (displayed in the demo): The ROM attached has the Mystique logo in place of the 69 position. Mystique.bin Quote Link to comment Share on other sites More sharing options...
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