Stoog
Member
Hmm need a little hand with this one
Boots up black screen somtimes does start up and work but missing ladders and platfoum sprites but thats another issue just need to fix what i wrote below
Now the werid part reset line working fine if i force it to reset as in turn it on and manually reset it i can somtimes make it boot but there is a still a issue when it goes through demo screen back to title screen then to demo screen it crashs and gets a stuck image going over cpu ram/roms all activity is just either stuck high or dead. its iike when it gets to that code in the boot eproms it tells to cpu to stop running or somthing on the data/address lines is causing it.
so far ill replaced a NE555 timer in reset circuit due to being very rusty and checked out any other parts which are fine. replaced boot ram, tried another known good 6502 cpu and reburnt the game eproms but still odd part is i cant work out why its so gone over cpu to rams and roms and cant find what is causing this unless its a timing isuue i really dont know
ive never seen this type of issue before where it crashs like that if i coin up the game i can play it fine for awhile so its a really good fault this one
Boots up black screen somtimes does start up and work but missing ladders and platfoum sprites but thats another issue just need to fix what i wrote below
Now the werid part reset line working fine if i force it to reset as in turn it on and manually reset it i can somtimes make it boot but there is a still a issue when it goes through demo screen back to title screen then to demo screen it crashs and gets a stuck image going over cpu ram/roms all activity is just either stuck high or dead. its iike when it gets to that code in the boot eproms it tells to cpu to stop running or somthing on the data/address lines is causing it.
so far ill replaced a NE555 timer in reset circuit due to being very rusty and checked out any other parts which are fine. replaced boot ram, tried another known good 6502 cpu and reburnt the game eproms but still odd part is i cant work out why its so gone over cpu to rams and roms and cant find what is causing this unless its a timing isuue i really dont know
ive never seen this type of issue before where it crashs like that if i coin up the game i can play it fine for awhile so its a really good fault this one
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