🚀 go-pugleaf

In article <1992Dec17.211743.2068@zip.eecs.umich.edu>, dmuntz@quip.eecs.umich.edu (Dan Muntz) writes:
> I'm trying to get an RT 16-bit 4-port card to work in a 486 isa box running
> 386bsd.  The card works if polled, or if another com device generates
> interrupts (all ports are checked on any com interrupt), but the 4-port
> card doesn't seem to be generating interrupts (IRQ 10).  I've seen
> two things in the RT tech ref.: 1) it looks like the 4-port card was
> designed to work in a PC AT (I'm not certain of this) and 2) RT 16-bit
> cards are supposedly *not* compatible with AT 16-bit cards.
> 
> Some questions:
> 
>   1) Are the 16-bit slots in an RT wired differently from those in an AT?
>   2) If so, can this be corrected with a soldering iron: perhaps by cutting
>      the IRQ10 trace on the 4-port (which one is it?) and wiring it to
>      either the AT IRQ10 pin, or a lower IRQ line?
> 
> Any info, slot diagrams, or random thoughts on the subject would be
> appreciated.

IRQ's on the RT are allowed to share interrupts, and most likely are
tri-state driven.  As far as I know, only slot 8 of the RT was
unique, all others were standard AT slots, and slots 3 and 6 were
XT 8-bit slots.

Here is some info on the 4-port card that I posted to a request eariler
in the year, might help..

Under AIX, and I assume AOS as well, the IBM book SA23-2605-0
shows the adapter to have the following features:

Slot positions: 2,4,5,7,8
I/O addresses:  range 1 1230-124F
                range 2 2230-224F
                range 3 3230-324F
                range 4 4230-424F
Interrupt levels: 9, 10, 11 (see note below)
Bit rates: 50 - 19200  (set by program)
Bits per character: 5, 6, 7, 8 (set by program)
Maximum number: 4

Notes:
 1)  If the RT PC 4-port Asyncronous RS-232C adapter (buffered)
     is instaled in the IBM RT PC 6192 Expansion Unit, only 
     interrupt level 9 can be used.
 2)  Interrupt levels CANNOT be shared between the system unit and
     the RT PC 6192.
 3)  All interrupt levels are shared, but interrupt level 11 cannot
     be shared with the SCSI adapter.  Also, interrupt level 9 cannot
     be shared with any of the 8-port async adapters.

Hope this helps.
Later,
markw
-- 
M. Whetzel 
Home: markw@antimatr.hou.tx.us        | IBM RT/125 running AIX 2.2.1 
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