Terminal driver for the COM port on an AT&T 6300+
hauerwas at hvrunix.UUCP
hauerwas at hvrunix.UUCP
Mon Mar 2 10:47:27 AEST 1987
The following is a message from the Vax System Manager here at
Haverford. I'm posting it to the groups I think might know how to deal
with it. Please respond through E-Mail to either "hauerwas!hvrunix" or
"A_HAUERWAS @ HVRFORD.BITNET" Thanks in advance.
* * *
I am trying to write a driver for the COM port on an AT&T 6300+ with
the OS Merge operating system. I am able to address the chip ports and can
send single characters out on the line (a line monitor has verified this).
However, I am unable to receive interrupts. The chip is posting the
interrupts but somehow they are getting masked out.
I am running on interrupt 4 (the default driver has been removed).
When I read the 8259 (PIC) enable register I get a value of 13 which means
that only interrupts 0, 2, and 3 are enabled. I enable interrupt 4 and read
the register which gives a value of 29 (as it should). However, on the very
next instruction I read the register again and the value has returned to 13.
Any ideas?
Bob Kostes
Systems Manager
Haverford College
Posted by:
--
Adam J. Hauerwas (Wonko the Sane)
Assistant Vax System Manager A_Hauerwas @ Hvrford.Bitnet
Haverford College hauerwas!hvrunix
Haverford, PA 19041-1392
More information about the Comp.sys.att
mailing list