jeff@drexel.UUCP (Jeff White) (07/11/88)
I have two questions about an NEC PowerMate 386 machine that a company I
work for has.
1. What is the proper way to install an 80387 math coprocessor chip? I don't
have a copy of the manual, but a contact I have who works with NEC's says
that the manual has no information on it. He said that NEC didn't want to
publish the information so people would have to get factory or serviceman
(read "pay for") installation of the chip. I have NEC's phone support
number, but about 40 minutes of trying last week produced nothing but
busy signals, so I wanted to see if the net might produce a quicker response. The motherboard is actually nice in that is has a ZIF (zero insertion
force) socket for the chip, making installation a snap. I originally
thought that the 387 should be inserted in the same direction as the 386,
which in this case would be writing upside down when looking from the front.
(Note - the socket does not have a bevel edge, notch, or anything usually
associated with "pin 1".) I was ready to put it in that way, when looking
on the motherboard, I noticed a small, white arrow that was sort of pointed
towards pin 1 on the 386. I found a similar mark near the 387 socket, but
it would be 180 degrees opposite of where the arrow is on the 386, so I'm
a little confused (okay, a lot) on which way to insert it. Not wanting to
fry a $500+ chip, I'll just wait until I find the correct way.
2. While looking over the 386 chip, trying to find some installation clue,
I noticed that it was labeled "80386-20", meaning it should be a 20 MHz
version. However, the machine is only supposed to be a 16 MHz machine, in
fact, of the 3 front panel lights, one is labled "16 MHz" (the other 2 are
"On" and "Disk"), I guess because the machine could be dropped down to 6 or
8 MHz. So the obvious questions:
Why put a 20 Mhz chip in a 16 MHz machine?
Is there any way to up the clock rate on the NEC to 20 MHz? What's the
best/easiest way to confirm that the clock speed is in fact 16 or 20 MHz?
If the machine can be driven at 20 MHz, will the '387 also run at that
speed? If so, should we see about getting a 20 MHz 387?
Thanks for any help.
Jeff White
Drexel University - ECE Dept.
rutgers!bpa!drexel!jeff