Re: Regarding interrupt sharing architectures!
- From: Tauno Voipio <tauno.voipio@xxxxxxxxxxxxxxxxxxxxx>
- Date: Sat, 04 Jun 2005 07:02:36 GMT
Jim Stewart wrote:
Paul Keinanen wrote:
On PDP-11's the "bus grant" card was inserted into empty card slots to get interrupt continuity.
Unfortunately these "continuity" cards were very small, installing one into a slot previously occupied by an other card would either cause a few bleeding fingers :-) or you had to remove the neighbouring cards, insert the small bus grant card and then reinstall the original cards.
Just a minor detail, if the bus grant card had been of full size, there would not have been any problems installing or removing it when actual cards were removed or installed.
Field service calls were not unusual after a customer "reconfigured" their machine and didn't get the bus grant card right.
I spent my early 20's maintaining DEC and DG minis. I have a working pdp 8/l in the garage.
There was a similar daisy-chain of interrupt and DMA chains in the DG minis.
Tauno Voipio tauno voipio (at) iki fi