As mentioned in a previous post, when I converted my Jumping board to Rainbow Islands I noticed that all the text in game was black. Going back through some pictures I took when I first got the board I see its present there too.

So where do I start?
I know from making my conversion that the palette values are stored in the program ROMs and they are pushed out to the palette RAM at address 200000.
I looked at the RAM with a scope and all seemed fine plus all the other colours seemed fine.
I also know that all the values required for this text colour is when the 2 least significant bits (A0 and A1) are active, so I traced these out down to the video board.

After a long session of following various signals I came across a 74LS374 chip.

This had all its inputs stuck low but according the the scope had a fair bit of noise on them, enough noise in fact to make my logic probe see it as pulsing HIGH/LOW. Following these inputs over to the chip next door I see a 74LS273 with its outputs giving off this crazy signal.
I replaced the 74273 and booted the game

If you look carefully you can see the lower part of the text is missing and a bit scrambled. Taking another look at that 74374 chip and its outputs are still crazy despite having good inputs. After a quick desolder and replacment I got this

All fixed and now my conversion is totally complete.
I have left one bit of graphics the same as the Jumping. If you play the game, in the lower left corner, you number of current lives is displayed as blue stars. On the original these are small rainbows. Just a note in case I ever release my modified files and someone tries to sell it as an original or something.

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).

Had this board for ages and never bothered with it.
A guy recently asked me to check out the PAL dumps for Block Block but due to my board being broken Ive never been able to test so I thought id try and repair mine.

As you can see, the board looks a state

There is a suicide battery on these boards that is certainly dead. I removed this and went over to The Dead Battery Society and downloaded the desuicided ROMs.
After burning the two 27c020’s and a 27c512 and following the guide steps I got nothing but a black screen.
I removed the Kabuki CPU and replaced it with a standard Z80.
Now I get the RAM tests and they all pass OK then goes to a blank screen.

After a bit of head stratching I relised that the 27c020 is JEDEC compliant yet the 27c301’s that the board expects are not.
Time for a bit of modding.

I lifted pins 2, 24 and 30 on both 020’s and pins 1 and 22 on the 27c512.
I ran a link from pin 21 of the Z80 pin 24 of both 020’s and pin 22 of the 512. This is the /OE line.
I ran a link from pin 60 of the DL-020F-108U custom IC to pin 2 of both 020’s. This is the A16 line.
Link pin 30 from both 020’s to pin 1 of the 512 then link them all to pin 27 of the Z80 CPU. This is the A17 line.

That should not be complete and the game should boot.
I was able to test both the PAL dumps I have made now and they both work.

There is no sound on my board and it looks as though most of the sound circuit is rotton so wont be trying to repair that. Its a nice game but I have no interest in it at all.