Another computer with similar SIP hybrides is the ND-5000 and they are found on several places in the CPU, for instance in the - MMU, http://sintran.com/sintran/hardware/nd-5000/nd-324701.html - ALU http://sintran.com/sintran/hardware/nd-5000/nd-324704.html - Micro program instruction controller http://sintran.com/sintran/hardware/nd-5000/nd-324709.html My guess is that they are fast memory modules used in critical applications as the register file for the ALU, storage of the microcode or microcode cache and translation tables for the MMU in this case. My 5000 machine is not so easily accessed right now so I can't look at the chips mounted on it to find out any product numbers. G?ran Pontus Pihlgren skrev den 2014-12-08 10:09:

On Tue, Dec 9, 2014 at 2:01 AM, Pete Turnbull <pete at dunnington.plus.com> wrote: Though technically SIP is the correct term. I think you're making a distinction between a SIP IC and a SIP module, but both are correctly called SIP (Single Inline Package). I haven't seen those, but there was a brief period where RAM chips commonly had a SIP-like package with the leads formed in a staggered dual row arrangement extending from one side of the package body and in the plane of the body, known as a ZIP (Zigzag Inline Package): http://upload.wikimedia.org/wikipedia/commons/1/18/ZIP19%2820%29_Toshiba_DR… However, the ZIP package didn't survive long in the market because SIP modules then SIMM and DIMM modules had lower overall manufacturing cost due to the reduced overall pin count compared to socketing individual RAM chips.