Put a 10 or 22 uf on the reset connector
Enviado do meu Tele-Movel
Em 28/05/2016 18:38, "Richard Cini" <rich.cini at verizon.net> escreveu:
All ?
I pulled my old PC/AT off the shelf to see if I could get Windows 1
running on it (since I just located the Windows 1.04 SDK which I have
running in Bochs). It worked when shelved years ago, but it unfortunately
suffered some case damage from a leaky battery. No damage to the mobo or
cards thankfully. I replaced the battery with a 4-AA pack.
Basically, the PC won?t come out of reset. I tested the power supply with
a load tester specifically for PC power supplies and it reports power_good
and all voltages look good on a meter. So far, so good. I dug out my ISA
POST diagnostics card which also has a PG tester in it. This reports no_PG
but I do see the reset pulse on the bus. Not sure why one would report OK
and one not.
I have a spare generic power supply (which also tests good using the same
tester) and produces the same result. I have no cards installed but I tried
it with floppy/hard drives both connected or not connected.
I traced the PG signal from the power supply through the 82284 clock
driver/ready interface chip and the PG is definitely there (transitioning
L->H on power-on) and RESET is transitioning H->L.
Any recommendations on where to go from here? Does anyone
have an extra PC/AT motherboard they would be willing to part with?
As an aside, would this have been a typical development machine? AT was
introduced in August 1984 and Windows 1.04 was released in 1987 so I?m
guessing probably.
Thanks!
Rich
--
Rich Cini
http://www.classiccmp.org/cini
http://www.classiccmp.org/altair32