Today I decided to make my own SwinSID as I had the schematics and also had the parts laying about.
After a short time checking everything was going to the right places I fitted it into my C64 and fired it up.
As expected it works just fine.
The board still needs cut down to size. I didnt add the ground planes on this one due to some through hole issues.
Thanks to Swinkels for making the SwinSID software
Zabanitu has sent me his schematic that has been reverse engineered from the (Konami) 501 replacement board on his bootleg Pooyan.
At this point it is untested and maybe there is even a possibility this will work on a genuine board too?
Here is the Eagle CAD schematic anyway should anyone want to try this out
If you do, please let me know what the outcome was.
Thanks
DOWNLOAD
Got Stiggys other VIC20 the other day, it wont load anything via the serial port and just reports back “DEVICE NOT PRESENT”.
According to Ray Carlsen this can be caused by a dodgy 7406 IC and he wasn’t wrong.
I checked all the states of this chip with a logic probe and all seemed to be as it should be so I went through each gate with a logic pulser and checked for its output. The outputs on pins 4 and 6 were stuck.
Removed the chip and eventually found one on a C64c motherboard that was scrap.
Replaced and tested with a demo and a couple of games.
I also took this opportunity to try out the VIC20 JiffyDOS (PAL).
My original test with JiffyDOS on this failed, nothing would load up. Turns out there is an NTSC and a PAL version, the later being significantly harder to find but we got there in the end.
Got this Rainbow Islands bootleg yesterday.
The game worked when I tested but was told about a dodgy ribbon connector before buying it so decided to take a look. Not sure what happened after that but the board refused to boot.
After finding a few stuck address lines I decided to check the program ROM’s. Found 3 that would not read properly so I replaced them.
In MAME it lists 2 of the program ROMs as being from the genuine Rainbow Islands set but these are double the size so needed to be split into 2 files and burned to 27512 EPROMs.
Probably worth mentioning that if you use the older 2005 ROMIdent program then the dumps from Jumping actually show up as 2 separate ROMs. Must have been like this at one time.
Booting up now gives me a screen of garbage
Every now and then I could make out a “SCREEN RAM ERROR” message. The screen RAM is located on the second board and suspected this is what happens when the ribbon connector got a bit wrong but couldnt get the game to boot again no matter what I did so I decided to socket the 68000 cpu and see what was going on, kinda wish I hadnt now as I got this
Accepting the error just kept flagging more “tied bits” errors. Turns out this was a red herring as these lines are controlled by a PAL20L8 chip and everything passes if this is removed. Wasted a little bit of time on this.
After taking a careful look at the connector it turns out the plastic housing that holds the ribbon cable in place was damaged and this allowed the ribbon cable to come away from the pins. I properly reseated the cable and tested, the board now fires up in all its crazy bootleg glory
The game plays pretty much like Rainbow Islands does but some of the sprites and names are different and I think the secret rooms don’t work too well.
This game has 3 PAL chips on it, unfortunately all are security locked and I am only able to read 1 of them (might be able to read the one on the video board but never tried).
After a few different designs and trials I think I’ve finally settled on something I like.
I’ve pretty much got double sided boards sorted but making vias are a pain but it works and looks OK.
As you can see this is destined to be fitted in Stiggy’s machine. It still needs cut down to size but im happy with that.
Sorry, I wont be making these for other people so please don’t ask.