Coleco "head to head' tv unit

Coleco "head to head' tv unit
by gannon on 2006-07-05 (#15088)

I picked up a couple of the 2 player sets today for $2.50 from my local walmart. I figured I could open them up to check if they were NOACs or not, and if not have a few parts/project cases incase I needed them.
So far I have all the small stuff figured out (power, ground, clock, a/v, whether or not it is a NOAC, etc...), but I'm not sure how to go about mapping the glob-top rom. I know it's been done for the GOAC (although that was a glob-top pcb soldered to the board), so I'm sure it's plausible, just not sure how hard it'd be.
It's the smallest NOAC board I've seen so far at 1.5"x1.5"

by tepples on 2006-07-05 (#15095)

Are you sure it's an NES on a chip, not a Colecovision on a chip? I'd imagine that because the Colecovision, the MSX1, and an early Sega console used pretty much the same chipset, this chipset might be ASIC'd too.

by gannon on 2006-07-05 (#15101)

21.47727Mhz clock, 5V, 5 pin controller connections, rom chip has 55-57 connections (didn't count too hard), also the interviews on the net I've seen with people who supposedly worked on it talking about the pluses of porting rather than making a custom chip. Not too solid, but it's pointing in that direction

Re: Coleco "head to head' tv unit
by kevtris on 2006-07-05 (#15102)

gannon wrote:
I picked up a couple of the 2 player sets today for $2.50 from my local walmart. I figured I could open them up to check if they were NOACs or not, and if not have a few parts/project cases incase I needed them.
So far I have all the small stuff figured out (power, ground, clock, a/v, whether or not it is a NOAC, etc...), but I'm not sure how to go about mapping the glob-top rom. I know it's been done for the GOAC (although that was a glob-top pcb soldered to the board), so I'm sure it's plausible, just not sure how hard it'd be.
It's the smallest NOAC board I've seen so far at 1.5"x1.5"

Yeah I have one of these... it is indeed an NES on a chip as far as I can tell, with a multicart on a chip attached.

I have a "intellivision" unit which is also an NES on a chip, though it has two 512K byte DIP ROMs, which I desoldered and dumped. The mapper is an MMC3+extensions like many other pirate carts and such.

Unfortunately, it's not possible to RE too effectively- I was thinking of making "bankwatch jr" using some special ROMs, but haven't gotten around to it.