trs-80 model II trouble--problem solved..and follow-up

On 17 Dec 2009 at 21:07, Fred Cisin wrote: Let's put this in its historical context. When Intel started making 16K 16-pin DRAM, yields weren't terrific, so they sold a limited number of "half-good" parts--2109s early on, probably to mark their territory. About 1978-79, the US got in a trade spat with Japan over DRAM "dumping" and the supply of DRAM abruptly dried up (pesaging other similar periods yet to come). You couldn't find 16K DRAM for any price in quantity. There was at least one break-in for the sole purpose of stealing DRAM that I'm aware of, nearly putting the firm out of business.. (Later, there was a hijacking of a truck carrying mostly CPU chips, but that's another story). The Mercury-News archives doubtless has the story somewhere. So, given the situation, sifting through 8K DRAM to find decent 16K parts was quite reasonable. I recall that our 2109s were tendered somewhat apologetically by our Intel sales rep when we asked for 2117 DRAM engineering samples. These were the purple ceramic carriers with gold lid version. Plastic was later. When the antidumping order was lifted, we received a bunch of NEC uPD416s. We were surprised at how much better they were than the Intel parts (I still have those too). --Chuck