Here is what has been going on on the CDC 6500: More Memory!
I’m sure the computer purity police will come and take me away, but this is what I have been doing. We are now up to 22 new storage module replacements, 17 of which you can see here. There are 3 more in chassis’s 9 and 10, and PP0 and PP1 each have one in chassis 1. I have 3 more to finish assembly of, when the parts come in later today.
Of the twenty units I have used in Central Memory, they are all involved in getting the First Location of banks 20 to 37 working, and that is all that works so far. If I try to test the second location, the first location fails. I don’t think the other three boards will get me through the second location, so I will probably be going out for more modules later today, or maybe next week.
My poor little milling machine has been working its bearings to the bone making Storage Modules sides and fronts. Since it doesn’t have “rigid tapping” (read automatic tapping), I started doing that by hand, but eventually I figured out a way to have the milling machine supply the energy to turn the tap, while I manually told it which direction to turn it.
So far, all the modules built have had the surface mount assembly done outside the Museum, and we have installed the pins and transformers. I may see about trying to convince other folks to do the through hole assembly and the machining.
Things are improving, we have moved from 65536 locations of memory to 65552 locations that work. Unfortunately it doesn’t work well enough to let the machine run with it out there, I still have to completely disable the upper 64K in order to have the machine boot.
Bruce Sherry 20170630