JAMMArcade.net – Page 236

SD2IEC boards

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 Comments Off

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.

Commodore 128 repair log #3

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 Comments Off

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.

Jumping to Rainbow Islands conversion part 4

General 3 Responses »

Feb 192012

Well today I finally finished the conversion.
Ive been doing the title screen conversion over a few days as its a very boring task

As you can see, the palette isn’t correct when originally copying the image over so this has to be changed manually after its all complete.

Once complete though, its identical to the original

All the graphics have been changed to original RI ones and plays pretty much the same.
There are still a few differences:
1. Some of the DIP switches do nothing.
2. Every now and then the sprites when a monster is killed are messed up. Cant locate the code where its going wrong.
3. Secret rooms do not work.

I can honestly say all of the images were taken from my conversion in MAME and not from the actual Rainbow Islands ROMs.
I haven’t actually tested it on the real hardware yet so it may not work the same as it does in MAME though. Fingers crossed it does.

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