286 -> 386sx Upgrades

[Ray Shwake]

rcd at ico.isc.com (Dick Dunn) writes:

>I tried several times to upgrade an old NEC APC-IV.  That's their basic AT
>clone from some years ago.  The first attempts at upgrading were add-in 386
>boards, either plugging directly into the CPU socket or plugging into the
>bus with a cable to the CPU socket.  Either they didn't fit (given space
>constraints on the board) or didn't work (somebody playing BIOS games, I
>suspect; that always gets UNIX).

	None of this surprises me based on my experiences with NEC's 386/20.
I'd considered upgrading mine given the absence of memory cache and limited
(and EXPENSIVE) memory expansion potential. Given my own suspicions
regarding form factor, screw bracings and connectors - and considering
that floppy, serial and parallel controllers run off the motherboard -
I decided that it was not worth it.

	Hey, it's not *that* bad a box, and it's certainly adequate to
support my DOS and Xenix work, not to mention occasional ISC UNIX work.
I can always buy a more powerful box for more serious work. Given the
radical surgery obviously called for with the APC-IV (and with some other
boxes) it may be appropriate just to keep it around for AT-class use.