More Bleepload fun

I was checking how “Bleepload” hands control over to “Bleepload Special” in “Bubble Bobble” when I stumbled on some code leftover in one of the blocks involved in the handover (set a breakpoint on execution at $BF1A and then check RAM contents thereabout):

Bubble Bobble: leftover code by Luigi Di Fraia

Bubble Bobble: leftover code

Guess where the source code is from? If you had a look at the Bleepload source I published on my DokuWiki space yesterday, you might have recognized that, in fact, the above snippet is from the tape loader itself:

        JMP B1D12     ; Return from IRQ
 
; --------------------------------
 
; IRQ #2
 
V1CFB   SEI           
 
        JSR S1D15     ; Read bit
 
        BCC B1D12     ; Return from IRQ
 
        LDY $72       
        LDA $BD       
        STA $033C,Y   
        LDA #$01      
        STA $BD       

OK, so the original labels and their corresponding labels in my disassembled listing are:

NOBYTE = B1D12
PROG   = V1CFB
BIT    = S1D15

Why is this relevant? If one of you happens to find a disk with some assembly source that looks like the one below, then you might have found the original Bleepload tape masterer’s source code:

        JMP NOBYTE    
PROG    SEI           
        JSR BIT       
        BCC NOBYTE    
        LDY 114       
        LDA $BD       
        STA 828,Y     
        LDA #1        
        STA $BD       

Happy digging 🙂

About Luigi Di Fraia

I am a Senior DevOps Engineer so I get to work with the latest technologies and open-source software. However, in my private time I enjoy retro-computing.
This entry was posted in Retrocomputing, Technical and tagged , , , , , , . Bookmark the permalink.

1 Response to More Bleepload fun

  1. Pingback: Some insight on Bleepload Trigger | Luigi Di Fraia's e-Footsteps

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