macadam bumper
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- Flight Lieutenant
- Posts: 257
- Joined: Wed Jul 14, 2010 7:37 pm
- Location: lancashire GB
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macadam bumper
My copy of Macadam Bumper while loading fine and seems to respond to options on screen seems to have a problem starting my keys to get the ball into the start position and releasing the ball doesnt seem to work , am i not presing a perticular key ? I notice someone on utube who was trying to compare it with macadam bumper on various machines couldnt get the ORIC version to work either ? any toghts or instructions would be appreciated !
Re: macadam bumper
Did you first insert coin(s), then pressed the start button as many times as players want to play?
(respectively P and D keys)
(respectively P and D keys)
Re: macadam bumper
Doesn't work though.
I've tried both versions I have and you get a sound when you press P but no credits, so you can't start.
I've tried both versions I have and you get a sound when you press P but no credits, so you can't start.
Re: macadam bumper
Ok then, it sounds like an emulator problem.
I have no problem with Euphoric, but can't start a game with Oricutron.
I have no problem with Euphoric, but can't start a game with Oricutron.
Re: macadam bumper
Well, now Oricutron is fixed and you can play Macadam Bumper!
Short info about the bug-hunting:
In common the problem was that you can't insert coins to start game i.e. pressing 'P' does nothing,
this is disassembled part of related code:
at address $6E45+$0F is stored the value of CREDITS, and because the Z-flag wasn't updated properly by ADC instruction,
so the BEQ was executed always and the new incremented CREDITS-value was never stored back to $6E45+$0F ...
The result is clear: No Money No Funny !
Short info about the bug-hunting:
In common the problem was that you can't insert coins to start game i.e. pressing 'P' does nothing,
this is disassembled part of related code:
Code: Select all
L1E22: ldx #$0F ; 1E22 A2 0F
L1E24: sed ; 1E24 F8
clc ; 1E25 18
lda L6E45,x ; 1E26 BD 45 6E
adc #$01 ; 1E29 69 01
cld ; 1E2B D8
beq L1E31 ; 1E2C F0 03
sta L6E45,x ; 1E2E 9D 45 6E
L1E31: jmp L1DC3 ; 1E31 4C C3 1D
so the BEQ was executed always and the new incremented CREDITS-value was never stored back to $6E45+$0F ...
The result is clear: No Money No Funny !