11 Jan
2019
11 Jan
'19
11:59 a.m.
On 1/11/19 2:32 PM, Noel Chiappa via cctalk wrote:
MicroPDP box has first three slots A-B-C-D to support PMI
memory and the rest are serpentine A-B.
Even giving a bus grant problem, I can't see that causing a CSR
error. I will probably have to dig out another box this weekend
just to be sure there isn't a problem with the backplane.
bill
From: Allison
Parent
Most Probable cause is interrupt grant is broken.
The only -11 that complains if the grant chain is broken that I know of is
the /34 (maybe the /04 too). I certainly have a QBUS chassis right next to my
workstation here that i) has a bunch of empty slots, and ii) works fine, as
long as there are no empty slots between the CPU and the devices.
Also, IIRC he said it works with 3 cards plugged in, but not 4; how can
plugging a card _in_ cause grant problems?
For most microspheres backplanes the first three
slots are different
than remaining.
That might be worth checking into. I'm not familiar with the second box
he's using, so can't help there.