channelmaniac
Veteran Member
Yes,
AST really did make a sidecar for the Jr! But I cannot find any documentation for it! Do you have some?
The JRC-128 has 128K of RAM, a parallel port, and a battery backed clock / calendar on onboard and it uses a bog standard coin cell! No NiCd or nasty alkaline (like Microsoft used on their Jr Booster) on this card.
BUT, it also has a 8 position DIP switch, a jumper labeled IRQ7, and 2 blocks of 3x2 .100 header pins with DIP shunts on them.
The S/N of this one is 1169, but the main memory controller chip is made by VTI and is labeled:
VL4501-20PC
TMS4501-20NL
ENG SAMPLE
I'm looking for documentation so I can upgrade this to 512K of RAM. While waiting, I'll compare this to the Racore expansions that used the 4501 chip and at the 4501's data sheet to see if I can figure it out... It isn't labeled, but I'm willing to bet it has bad RAM since it's full of Micron Technologies 64K DRAM.
AST really did make a sidecar for the Jr! But I cannot find any documentation for it! Do you have some?
The JRC-128 has 128K of RAM, a parallel port, and a battery backed clock / calendar on onboard and it uses a bog standard coin cell! No NiCd or nasty alkaline (like Microsoft used on their Jr Booster) on this card.
BUT, it also has a 8 position DIP switch, a jumper labeled IRQ7, and 2 blocks of 3x2 .100 header pins with DIP shunts on them.
The S/N of this one is 1169, but the main memory controller chip is made by VTI and is labeled:
VL4501-20PC
TMS4501-20NL
ENG SAMPLE
I'm looking for documentation so I can upgrade this to 512K of RAM. While waiting, I'll compare this to the Racore expansions that used the 4501 chip and at the 4501's data sheet to see if I can figure it out... It isn't labeled, but I'm willing to bet it has bad RAM since it's full of Micron Technologies 64K DRAM.
