CPU upgrades, pt. II

Anyone come across an "XTEND MICROPRODUCTS" processor upgrade card for MCA machines? I've found one inside my PS/2 Model 50, which I was previously unable to identify as the markings on the PCBs are hidden inside the "sandwich" IYKWIM. Anyway, it appears to replace the onboard '286(?) with a '486SLC (no real clues as to clock speed, but could be 25MHz) and has a socket next to the processor which I'm assuming is for a math co-processor? Would I be correct in assuming that the system will not start up if the 72-pin SIMM sockets on the upgrade board are empty....I've never gotten very far with this machine as I don't have any 72-pin SIMMs to try in it? TTFN - Pete. -- Hardware & Software Engineer. Sound Engineer. Collector of Arcade Machines, Games Consoles & Obsolete Computers (esp DEC) peter.pachla(a)wintermute.org.uk | www.wintermute.org.uk --