It's almost a real computer now :-)

I've seen your soldering :-)

Me ! I do ! Me !

Please don't do this ! It does nothing except put your posts twice in every ones feeds, which is quite annoying.

Look between the backplane and the front panel, there's a 3C-PO. Spencer calls it a "Port-Output" shim, but I call it a "Peter-Onion" as I pointed out it was needed and what it had to do. I even had a working version before Spencer produced the shim. Also there's a 3C Rom programmer on the desk !

You may have damaged the chip by running it without the -12V applied. It depends on what the -12V was used for. In some early LSI devices it was used as the back bias for the substrate which kept all the gates isolated from each other, without it they all connect to each other via the substrate.

Oh yeah, we've all been there :-)

Tut tut, not reading the fine data sheet completely !

Thanks to you and Tim. A fun afternoon. I was surprised by the attention drawn by the green screen CRT on my CP/M machine :-)

CMake is my weapon of choice these days for C projects, but this seemed ripe for just a simple make file :-)

Machine code a.k.a T2 code (as the library programme that reads it is called "T2"). See www.billp.org/ccs/gtp803/g...

Starting at 1000 and running for an hour my version factorised 5586 numbers, that's 1.27 times the original version. Starting at 1048576 (2^20) mine factorised 1965 numbers in a hour, that's 2.6 times the original version.

However, it doesn't actually calculate the prime numbers and just tries 2 then all the odd factors from 3 upwards. This makes it very inefficient for large numbers. So I have written a version that calculates the primes as they are needed and keeps them in a table.

It calculates and prints prime factors starting at the number set on the keyboard. There are some devious instruction sequences in it, so the programmer must have been very experienced. But I've made it go a bit faster using a trick of my own.