On Dec 18, 21:39, Richard Erlacher wrote: whatever. cache combined 64kByte That's my experience, too. Looking through my pile of early-90's memory data books, I couldn't find that number listed. However, I found a couple of 32-pin SOP devices made by Samsung that are 64K x 8: the KM68512 is 32-pin 64K x 8. It has the same pinout as the more common 32K x 8 28-pin cache SRAM devices, except that pin 30 is an active-high CS (that would be pin 28, Vcc, on most 28-pin 32K x 8 devices), pin 31 is A15 (the extra address line), pin 32 is Vcc, and pins 1, 2 are N.C. (pin would be A16 on a 128k x 8 device). Apart from the NC on pin 2, that would make it the same pinout as the common 128k x 8 devices. Incidentally, although the Samsung book lists lots of other manufaturer's equivalents for nearly all their devices, there are none listed for the KM68512. It's obviously not a common configuration! FWIW, several motherboards did use 4 chips rather than 8 for certain cache sizes (mine uses 4 off KM681001 for 512K x 8 cache). There are a few other devices that might fit the description, except that they are BiCMOS centre-power devices (Vss and Vcc are in the middle of the sides, not at the corners). It's very unlikely that any motherboard used such chips for cache, I think. Check where the 5V connection goes, and if it's on pin 32 (and possibly pin 28), I'd assume it's the "normal" pinout, and similar to the KM68512 I found. -- Pete Peter Turnbull Dept. of Computer Science University of York