rg.jones@rogers.com wrote:
Michael J. Mahon wrote:I don't mean to be a party-pooper, but does it *look* like a Zip Chip?lol ;-) Yeah it's a zip chip alright - same packaging as the 4Mhz one I bought in the mid 80's. Even has some of the same small bumps under the epoxy on the flip sde as the 4MHz one. The sticker is gold with zip8000 on it.Most failures in a Zip Chip would render it either non-working or unreliable, but not slow.Agreed - I was kind of suprised that it would still function fine in slow mode.Of course, such a failure is possible, but unusual.Normally, to boot it slow, you have to hold Escape while resetting.Right .. Fast mode is the default and pressing ESC drops it to slow mode. It behaves the same way wether or not ESC is pressed. I also tried the chip in a IIe - same thing.
Truly a wierd failure. This would be the result if the tag SRAM failed, so that all accesses to cache were treated as misses. It is now functionally a 65C02. ;-(
My 4Mhz chip on the other hand doesn't work at all anymore - it only lasted a few years or so and that was a replacement for the original dud they sent me in the first place.
Yes, they had a run of bad SRAM in one of their early runs. It may have killed them, in the sense that it requires a *lot* of warranty replacements, and essentially emptied the product pipe for months. It also put considerable stress on their "customer service department" which was never very good. ;-) I consider myself fortunate to get my two marginal chips replaced, after only 5-6 months of mutual harrassment. ;-) My replacements are going strong after all these years--knock wood! -michael Parallel computing for 8-bit Apple II's! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it is seriously underused."