about the future (missing ICs)

[g4ugm]

Bitsavers has a good collection of 1620 documents, including the Leeson and Dimitry 1962 book. The Caffey book is another good one, but I can't locate an online copy for you.

One obstacle is getting past the brutal simplicity of the machine, particularly the Model I--you had to load the addition and multiplication tables into low memory in order to do arithmetic, for example.

In many ways its simpler than the Ferranti Pegasus that is my current Work In Project so I can better demonstrate the emulator at www.mosi.org.uk. That had a drum , which it really treated like main store, but that also held some basic support routines for number output....

 

[Chuck(G)]

Ah, sort of like the Royal-McBee/Librascope LGP-30. Another "minicomputer" that time's forgotten.

 

[woodchips]

I am not sure that simulators will ever get anything more than a yawn. You have to see, and use, the real thing. I have just got working a 64K IBM 5150 PC, and I had to smile as it slowly loaded DOS and started working. Similarly it is a poor year if I don't get to see the only flying Lancaster come over at least 5 times a year, I watch, and listen, it out of sight, how to you emulate that?

How many people are repairing mechanical calculators? Look at the Marchant teardown on John Wollfe's web site and be amazed. But remanufacturing parts for the Marchant is a serious problem.

Up unto the middish 80s custom chips were not too complex, their logic could be recreated by simply using a logic analyser. Early logic chips were so simple that recreating them using discrete transistors is possible. I am trying to get a core store running, but even after a real trawl of the web I am amazed at just how little information there is on them. I have yet to find the circuit diagram of a core store to see how it was done, for real.

Got to keep the real things running, somehow.

 

[giobbi]

I am not sure that simulators will ever get anything more than a yawn. You have to see, and use, the real thing. I have just got working a 64K IBM 5150 PC, and I had to smile as it slowly loaded DOS and started working. Similarly it is a poor year if I don't get to see the only flying Lancaster come over at least 5 times a year, I watch, and listen, it out of sight, how to you emulate that?

How many people are repairing mechanical calculators? Look at the Marchant teardown on John Wollfe's web site and be amazed. But remanufacturing parts for the Marchant is a serious problem.

Up unto the middish 80s custom chips were not too complex, their logic could be recreated by simply using a logic analyser. Early logic chips were so simple that recreating them using discrete transistors is possible. I am trying to get a core store running, but even after a real trawl of the web I am amazed at just how little information there is on them. I have yet to find the circuit diagram of a core store to see how it was done, for real.

Got to keep the real things running, somehow.

I agree, 100% :thumbsup:

Now what we need is just somebody that reverse engineering all the custom chips and make replacements available...