[comp.sys.ibm.pc] V30 compatibility with 8086-2 ?

john@wa3wbu.UUCP (John Gayman) (10/19/88)

       I encountered a strange problem in trying to install a V30 chip
in a Panasonic Business Partner (FX-600).

       The machine currently has a 8086D-2 CPU. I ordered a V30 (8Mhz)
from Jameco. They advertise a Part no. UPD70116-8 which is said to replace
a 8086-2. Anyway, I get the chip and it says Sony on it, with a part
number of CXQ70116P-8 and says "Copywrite NEC". I put it in place of my
8086 and when I tried to boot the machine nothing came up on the monitor
but my "Printer" spit out "PIT count test failed"!

       What gives here ?  Did I simply receive a defective V30 (Why does
it say Sony?) or is there some incompatibility issue that I have fallen
prey to ? Any guidance is greatly appreciated.

					
					John



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jpd@usl-pc.usl.edu (DugalJP) (10/22/88)

In article <650@wa3wbu.UUCP> john@wa3wbu.UUCP (John Gayman) writes:
>
>       I encountered a strange problem in trying to install a V30 chip
>in a Panasonic Business Partner (FX-600).
...
>but my "Printer" spit out "PIT count test failed"!

John, I believe your machine is telling you it failed the Programmable
Interval Timer test (PIT, the 8253 chip).  This happens because the V30
executes instructions faster than the 8086, leading the self-test firmware
to conclude that the clock was running slow.  If your system continues
to boot, you should just ignore the diagnostic.  If it refuses to go
any further, you'll have to patch the firmware to use the V30.

-- James
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-- James Dugal,	N5KNX		USENET: ...!{dalsqnt,killer}!usl!jpd
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berger@clio.las.uiuc.edu (10/22/88)

That's the right part number.  I wouldn't be surprised to hear that
Sony is second-sourcing the chip.

Many microcomputers have software timing loops built into the ROM.
I've encountered problems with disk boot procedures for that reason.
Its possible that your power-on printer diagnostic check has similar
troubles.

			Mike Berger
			Department of Statistics 
			University of Illinois 

			berger@clio.las.uiuc.edu
			{convex | pur-ee}!uiucuxc!clio!berger