26 Mar
2005
26 Mar
'05
12:30 p.m.
Jim,
I've never done it, but remembered reading about it. I've looked up the
procedure in Upgrading and Repairing PC's by Mueller.
Find the 8284a (82284 in the AT) timer chip in the PC. When pin 11 is
shorted to ground momentarily it will start the reset process. Also
shorting the "power good" line from the power supply will do the same
thing. The power good pin is supposed to be P8-1.
Whether it's a warm reset or a cold reset depends on the memory contents
of a certain memory location. Doing a Cntrl-Alt-del sets it up for warm
resets from there on out.
If you work with early PC's, Muellers book should be on your list of
books to buy. I actually have 2, but different revisions, since the
contents are a bit different in each.
Chad Fernandez
Michigan, USA
Jim Leonard wrote:
Has anyone ever wired up a reset button/switch for
their IBM PCs? I
find myself powering down-then-up my 5150 three times a day when all it
needs is a hard reset to reboot a hung machine. I've searched the web
and usenet archives for such a design or specs but haven't found
anything. If I could soldier a few wires to a pushbutton, I feel like I
would less harsh to the machine...
Or, does it not really matter? Is it not a big deal to power down, then
power up (after 5 second delay) a 5150 or 5160? I know IBM PCs were
built well, but I am unwilling to find out *how* well :)