On 1/11/19 3:34 PM, Jerry Weiss wrote: > On 1/11/19 11:28 AM, Bill Gunshannon via cctalk wrote: >> Well, it has been so long since I had to put together an >> entire system I forgot what fun it can be. >> >> With almost documentation I was able to configure 4 1meg >> memory modules and I tested them all in my 11/23+ box. >> >> >> KDJ11-B with 4 different (but similar) memory cards. >> "MAP" option of the KDJ11 shows 4 meg (minus the I/O >> Page) and all the right CSR's for the first four blocks. >> >> Really wanted to make this a deskside so I moved the >> cards to a MicroPDP box (Yes, I have a coule of the >> deskside pedestals). Power on, Memory CSR error. >> Move then back to the 11/23+ works fine. If I only >> put the first three in the MicroPDP box it works. >> But as soon as I try to put in a fourth module I >> get the memory CSR error. Tried different cards >> (although working in the 11/23+ box would make me >> think it is not a problem with the card) no help. >> >> Anybody care to take a stab at what might be causing >> this problem? > 1) You might want to check your power supply loading. You have a lot > of memory of chips to feed. The H7864 output at +5V is 36 amps. > Between the KDJ11-B and 4 memory boards you may be using between 20-25 > amps. Add a disk controller, disk drive and any other Q-bus devices > might bring you close to the limits for either +5V or +12V from an aging > supply.
Nothing but CPU and memory at this point. And there will never be drives as I will be using SCSI and 6 of them sit in a box of their own just waiting for the PDP-11 to wake up and smell the coffee. > > 2) Are the CSR addresses between 17772100-06? Have you tried to move > them above this range just to see if the behavior changes? CSR's are right. As I said, the combo worked until I moved it to a different backplane. I think Allison has the idea. I am going to go back and look into bus grants. But I would have thought they would be alright as the likelihood of these being in a serpentine A-B box seems much to likely for them to not be capable of it. bill
