VP/ix problems

[uhclem at trsvax.UUCP]

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Make sure the serial adapters do not have a 8250_ or 8250B UART
part installed.  If so, replace with a 8250A, 82C50 or 16450.  If your bus
speed is above 4 MHZ, you really should have a 16450 or 82C50 since all
the others have too slow a recovery time, resulting in double reads of status
and dubious success in programming the chip.   The 8250_ / 8250B have numerous
race conditions that are unimportant if you aren't using interrupts (MS-DOS)
but fatal if you are (XENIX/UNIX).  All pre-AT IBM adapter cards and many
current clones used/use the 8250_ so the BIOS would be happy (in pre-AT, it
was coded to expect the bugs.)

Finally, make sure the modems are not set for LOCAL COPY or anything weird
like that.

						
					"Thank you, Uh Clem."
					Frank Durda IV @ <trsvax!uhclem>
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"If we took the bugs out, it wouldn't be MS-DOS, would it?"