Got a broken Super Chase board the other day.
All the PALs were unprotected and have been added. There are 10 in total!
Taito Super Chase PALs
PAL Updates
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Mar 022012
Feb 272012
Myself and my mate StiGGy were wanting another SD2IEC device for a couple of reasons. The other one I have was made by SirMorris and is still going strong but didn’t want to bother him with making a couple more so I asked him if I could have his original schematics which he very kindly supplied.
The result is 4 shiny new boards straight from China. I originally ordered 2 but for some reason they always seem to double up my order but I’m not complaining.
Ive got most of the parts on order but Farnell don’t seem to have the SD slots available that aren’t on US stock order (and extra £15) so ill look else where for those.
Added the last Street Smart PAL
PAL Updates
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Feb 262012
Today, for no reason other than proving to myself I could, I manually reverse engineered a PAL22L10 from my Street Smart board.
The PAL at location D11 was the only one on this board that was security locked so until now I couldn’t copy it.
Using the ABI to test I went through each pin individually and derived equations.
After my first attempt I thought I actually had it sorted but…..
Altogether it took quite a few hours to do so will probably not do this too often but the option is there should I need to but finally the game booted up and all the outputs on my clone match the original.
Feb 252012
Motherboard clearly had a dodgy ON/OFF switch.
Removed it and replaced it with one from a C64.
On power up I had a blank screen.
Did a few quick checks with the scope and all data/address lines were pulsing properly.
Checked the voltages with a multimeter, the 5v was present but the 9VAC was not. Traced this right the way back to the switch I had fitted.
When I soldered the new switch in, one of the legs musnt have made a connection as they were a little shorter than the original. I resoldered the legs on top of the motherboard as well as the underside and it now boots up.
One of the CIA chips was missing, fitted a new one and C64 mode now works too.
Namco PAL added
PAL Updates
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Feb 212012
I was contacted a few weeks ago with regards to dumping a PAL from a Namco PCB. The PAL is labelled SYS2V-2.
The chip arrived yesterday from Italy and it turned out to be the most difficult PAL16L8 to dump yet.
The output from the ABI was fairly unusable as it produced FAR too many product terms for some of the pins and would not compile.
Most of the pins were fairly easy to figure out from the listing but pin 12 was a little bit crazy. After a night with the logic analyser hooked up to it I had something that was almost the same in my simulation as what the real chip did. There was one state that did not match up but I emailed the .JED files anyway to see if I was anywhere near. Well so far so good as 2 of the games it was tested on seem to work now.
Although I cant test this myself Im hopeful its OK and its on my download list now.