> On Nov 1, 2022, at 7:59 PM, Chris Zach via cctalk <[email protected]>
> wrote:
>
> On 11/1/2022 11:49 AM, Ethan Dicks via cctalk wrote:
>> I don't think the 11/750 could have handled that many users on DZ-11s.
>
> I think this is why COMM-IO-P systems were sold. They basically acted like
> front end processors for a stack of DZ11's to interface to a Unibus system.
>
> Problem was those communications processor boards only had enough microcode
> to handle either block lines or async lines but not both. When the fruitcakes
> at HKJC demanded that they support the betting systems (polled block oriented
> devices) and async terminals (for betting odds and displays and such) for the
> mighty Sha Tin Totalizer (multiple 11/74 type systems and a boat-ton of 11/04
> front ends connected by those weird IPC connections) all hell broke loose.
>
> Literally.
You'd think the obvious answer would be to use two KMC11s rather than just
one...
The big win from those coprocessors is that they could offload not just simple
DMA, but also protocol processing like DDCMP or even BISYNC.
HKJC, now there's a designation I haven't seen in many years.
paul
