I've come into possession of a NEC Powermate SX (not the Plus version) which is described as a "8/16Mhz" system. It has a 16Mhz 386SX on a little expansion card that plugs into the motherboard, along with a socket for a 387.
However I cannot get the chip to rate past 8Mhz. All the documentation I've been able to find does not suggest that the CPU's speed is physically set via switches or jumpers. Stason labels one jumper as "ATCLK clock mode select", but neither jumper position makes any difference on the CPU's speed. A technical document on ps-2.kev009 relabels that jumper as "sync/async mode", which isn't a much better explanation.
I do have the setup/diagnostic disk for the system, but it's limited to date/time, drive settings, and setting memory amounts. Nothing to do with the CPU at all.
I posted a similar question about the original NEC Powermate APC regarding a 286 at 8Mhz that seemed to be able to go to 10Mhz, but never got a reply on that one. It appears the NEC systems were not very popular I suppose, though I'm still hoping someone has some insight into this baffling problem.
However I cannot get the chip to rate past 8Mhz. All the documentation I've been able to find does not suggest that the CPU's speed is physically set via switches or jumpers. Stason labels one jumper as "ATCLK clock mode select", but neither jumper position makes any difference on the CPU's speed. A technical document on ps-2.kev009 relabels that jumper as "sync/async mode", which isn't a much better explanation.
I do have the setup/diagnostic disk for the system, but it's limited to date/time, drive settings, and setting memory amounts. Nothing to do with the CPU at all.
I posted a similar question about the original NEC Powermate APC regarding a 286 at 8Mhz that seemed to be able to go to 10Mhz, but never got a reply on that one. It appears the NEC systems were not very popular I suppose, though I'm still hoping someone has some insight into this baffling problem.