Hello
I have an A2000 A rev. 4.0. Such a model came with an internal memory expansion board (for info see TBBoAH, RAM expansions by Commodore). My board has 16 DRAM soldered giving 512K and 16 empty sockets. I would like to fill sockets providing extra 512K, but I am not sure which type of DRAM is good. The soldered ones are TMS 4257 chips, 256Kbit, organization 256x1, 150ns. Since it is not easy to find exactly those chips, I am considering other chips also,but which are good? Of course 256Kbit chips, but is any organization good? Also the TMS 4257 are "nibble mode" chips,as opposed to "fast mode" ones. Is it necessary to place "nibble mode" chips? If so,is there a way to deduce this characteristics from the chip ID?
regards
