Hi, All, I have some Hitachi parts, marked 21-18470-01, that I pulled from a DEC Professional 350 on an upgrade to 256Kx1 DRAMs. I am trying to track down a specific thing about them. I found a vcfed.org post about these same type chips in a DEC Rainbow and the question (but not firm confirmation) that they could be Hitachi 4864s based on DEC parts lists.
http://www.vcfed.org/forum/archive/index.php/t-24574.html It matters to me because I'm trying to find some 7-bit/128-cycle refresh DRAMs to stuff into a TRS-80 Model 4. I mostly have 4164s made by TI and such that are 8-bit refresh, so they won't do. If these are 4864s, then they'll do. http://www.minuszerodegrees.net/memory/4164.htm (I already have the GAL file for the Model 4 upgrade, so I don't need the reminder that the 128K upgrade needs more than just eight more RAM chips). Thanks, -ethan
