CAVELON on Galaxian bootleg deconstruction.

[Geekfix]

So many moon ago I bought this entire cocktail for £60, been left outside under a (leaky) tarp for several years...Sadly the cabinet was badly waterlogged/damaged and was beyond resurection. Happily the monitor was fine after a clean and a recap (and found a new home with @iddod)

The game board (Galaxian Bootleg Hardware) was a bit of a challenge but I eventually got it running (albeit its still hyper sensitive to the 5V rail, only seems happy at 4.6V, will have to investigate further) and seemed fine, but occasionally it behaves like there are no ROMs, this board has a super top secret epoxy boxed CPU & ROMS... So I quietly did a quick convert to Galaxians (single 27C128) popped in a Z80 and pf it went, ran every single time I tried it.

Now comes the deconstruction bit, see photos. After this and a clean, new sockets and dumping of PROMs the board now boots every time, interestingly the dumps from the EPROMs do not seem to exist! checked against http://www.arcaderestoration.com/romidentification.aspx nothing...Unknown. there is quite a bit of support hardware on this board though...Interesting, will upload dumps shortly...

 

[philmurr]

Nice work!

I have the same potted board, never tried plugging it in. Could you explain your de-potting technique?

 

[Geekfix]

Thanks!

I used a dremel with a sanding disc mounted, First tried to sepetate the ABS case…Eventually in bits, in places it was stuck firm to they potting epoxy, once I got that off I noticed tapping on it that the bottom sounded hollow. I actually used a soldering iron to push in that side and made a small hole, then I could see the cardboard it was wrapped in, just started carefully dremeling and prizing until I reached one edge of the pcb. then I tried to follow the edge.

 

[Macro]

The cavelon in mame also had a second Z80 and an AY soundchip, be interesting to see what sort of noises it makes on a standard galaxian PCB

 

[NivagSwerdna]

As a lover of tutankham that looks like a great game. Looking forward to looking at the ROM dumps

The board has a SN76489 which is a sound generator. I assume the white cable goes off to the audio section on the board?

NivagSwerdna2022-08-31 22:13:31

 

[Geekfix]

I do have some video clips of the game playing, will see if I can grab some audio, or post a short video. Thinking about I expected two Z80 and a Yam sound chip in this...you just reminded me. Thanks.

 

[Geekfix]

Also I will get the EPROM dumps up here soon, had a few days out of the workshop.
And yes the SN76489 is a sound generator and your correct that wire (yellow) is just connected to the volume control.

My Mr Do! board uses two for sound generation.

 

[NivagSwerdna]

Does it have a Z80 in the normal socket too? i.e. that is really just add-on sound?

 

[Geekfix]

No this just plugs into the Z80 socket.

 

[Macro]

Did you ever dump the roms for this ? be interesting to see what it sounds like with the other sound chip.