On Mon, Mar 8, 2021 at 1:37 PM Mario Kienspergher <contact_at_kinzi.net> wrote: > > Am 08.03.21 um 18:39 schrieb Jim Brain: > > On 3/8/2021 11:29 AM, Bill Degnan wrote: > > Hi, > I have a strange C64C (I believe) motherboard with: > > PCB ASSY NO.250451 > PCB No. 251915 Rev.2 > > ...printed on it. I don't see this board documented in the normal places > and the PCB does not come up in a search, any ideas? The VIC-II is missing. > > https://www.vintagecomputer.net/commodore/64C_250451/250451_251915_pic1.jpg > > Thanks > > Bill Degnan > > That's an odd one. Like a CR board, but with 8 DRAMs, though not ina 2x4 > config like on the 466 board. > > Indeed, looks like they were testing it but trashing it because of > problems, as the 250466 came much later with a NMOS VIC and old glue logic. > > IC-stampings are from mid/late '84. Maybe the HMOS-II-Version of the VIC > did not perform very well or the yield was too poor, or known problems with > other HMOS ICs (7501, 7360) forced postponing. > > Anyway, a sensational finding. Where did you get it from, Bill? > > -kinzi > It came from the estate of David Diorio, CBM engineer. It was donated to kennett classic, the nearby computer museum. There are a few CBM prototype-y things there. kennettclassic.com BillReceived on 2021-03-08 20:04:24
Archive generated by hypermail 2.3.0.
