> On Jul 1, 2017, at 10:59 AM, Noel Chiappa via cctalk <[email protected]> > wrote: > >> From: Jerry Weiss > >> So it would appear the upgrade board makes provisions for both >> situations. > > I'm not sure that the two situations that the upgrade board supports are in > fact different, from its point of view. (Assuming that the two situations you > refer to are the two different consoles.) Yes, the _system_ supports two > situations: i) the KY11-LA connecting directly to the backplane, and ii) the > KY11-LB going via the M7859; but the DEC CPUs don't seem to draw any > distinction between the two. > > Looking at the KY11-LA prints, the connector to the backplane cable (the one > which is unused with the KY11-LB) carries signals like "Halt Request" and > "Halt Grant", which are generated in the M7859 (which has its own direct > backplane connection) when using the KY11-LB. > > So as far as the consoles are concerned, those signals come to the backplane > via different paths, but as far as the CPU is concerned, it sees the same > things through its backplane connection, no matter which is in use - so how > would the upgrade board be any different? > > The _only_ cable(s) that ever connect(s) to the CPU board (in the KD11-D or > KD11-E) are from the KY11-LB: those cables are the ones that carry the signals > to support the microcode single-stepping. How would the upgrade board use > these? >
Yes, the upgrade board console wiring support exists only to ensure minimal plumbing changes to the chassis and backplanes of the system being upgraded, and of course to signal the KDJ11. There’s no need or benefit to connect the consoles to the UNIBUS backplane. Its just peripheral bus after the upgrade (i.e. neither a CPU or Memory Bus) similar to an 11/84. My assumption is that the Upgrade Board only requires/provides signals to either type of console to support basic human controls. Just HALT, Boot, INIT(?). The consoles are reduced to being toggle switches and a few indicator lights. ODT replaces the limited 11/34 conversational console emulator (?) and/or the programmers console. NO SS, DIS AD, LAD, LSR, etc functionality. I haven’t looked at the details of the LA/LB prints to see if the actual signals involved are really differ much between the two, other than the connector wiring. I’d be curious as to how/whether the M9301 bootstraps are used. The original bootstraps may not visible from the KDJ11 until some unibus mapping is enabled. Perhaps this is hidden by the upgrade board. The upgrade board seems like a smooth upgrade path. Sorry I didn’t hear about back in the day. Would have extended the life of more than a few of our systems. > > One thing that might help untangle the function of those two headers on the > upgrade board is to look and see what chip(s) they connect to. If they aren't > EIA transmitters/receivers, yes, they aren't serial lines. (I only suggesgted > that because I couldn't figure out what _else_ they could be.) Can that be > done? > Agreed. Jerry
