Atari 2600jr Unicorn

[LittleJoe]

I've finally come across one of these. Single chip C101688. My Harmony (1.3 firmware) doesn't seem to work with it, going to have give the latest firmware a try.

[Tr3vor]

Is this supposed to be rare or something? What is the Unicorn?

[HatefulGravey]

Is this supposed to be rare or something? What is the Unicorn?

 

Unicorns are never found, though many have looked. Unicorns are rare.

[Itchy Koala]

You're kidding. A single chip C101688 2600 Jr?!

Mind=Blown.

[jaybird3rd]

Interesting. I wonder what the other IC footprint (just under the cartridge port) was for. Did any 2600JR models come with a built-in game (or games)? It looks as if they were at least reserving some board space for a game ROM.

[Uzumaki]

Probably. The heavy 6 switch console also had the pad for game ROM but it wasn't implemented.

[alex_79]

It looks as if they were at least reserving some board space for a game ROM.

Yes, the empty IC footprint is for a built in game. There's a schematic of the console on digitpress site (Library->Tech docs->Atari VCS/2600->Atari 2100 "JAN" single chip)

[maiki]

I hope mine is Unicorn as well, if it has something to do with the fact it was manufactured in 1991. Anyway I'm not going to open it to destroy the label... So yes, I've got Unicorn as well and you're owned.

[Uzumaki]

It looks as if they were at least reserving some board space for a game ROM.

Yes, the empty IC footprint is for a built in game. There's a schematic of the console on digitpress site (Library->Tech docs->Atari VCS/2600->Atari 2100 "JAN" single chip)

 

Looking at the schematic, it has a very simple design for switching between cart slot and built in ROM. A pull up resistor to ROM's enable goes high if there's no cart inserted. A normal cart has ground connecting pin 12 and 24, which would pull the ROM's enable low, thus disabling the ROM for cart play.

 

Max 4k, no bankswitching support without extra chip support on separate PCB board. One could install a 2k/4k multi ROM with manual switch. But that'd be ruining a rare single chip 2600 console. Better to get Harmony to play everything.

[+batari]

I've finally come across one of these. Single chip C101688. My Harmony (1.3 firmware) doesn't seem to work with it, going to have give the latest firmware a try.

Harmony requires that pins 12 and 24 of the cart slot are both grounded. Firmware updates won't fix this - a hardware mod is required.

 

If you don't want to connect these pins in the console, you can connect them in the Harmony cart itself (I posted a pic somewhere on how to modify your Harmony.) Doing so won't affect operation, as the pins are only needed for initial testing of the boards when they are assembled.

[Pioneer4x4]

I've finally come across one of these. Single chip C101688. My Harmony (1.3 firmware) doesn't seem to work with it, going to have give the latest firmware a try.

Is there anything external that identifies it as being single chip?

[Uzumaki]

I've finally come across one of these. Single chip C101688. My Harmony (1.3 firmware) doesn't seem to work with it, going to have give the latest firmware a try.

Is there anything external that identifies it as being single chip?

 

Nothing definitive but it seems like serial number that begins with A19 are those made in 1990's and would have a single chip board.

[the.golden.ax]

Yep, I've had one as well, sent it to Longhorn. Guess he wasn't needing it (was going to send it back).

 

Very cool.

 

AX

[Atari Joe]

I have a few of these things 2600 unicorns are bad to the bone. Isnt that what Ben Heck uses to do his heck hacks? An offically produced AOAC pretty much. Jack Tramiel was as innovative as he was cheap.