peteronion.bsky.social
@peteronion.bsky.social
Retired (early) Software Eng. G0DZB occasionally /P on HF. Discoverer of the PI 2 Xenon Death Flash. Looks after the Elliott 803 at TNMOC
"They cut the hard line, you need to find another exit" (Morpheus, The Matrix So Mike, if you want to get home tonight you'll have to find the pay phone at the corner of Wells and Lake :-)
November 11, 2025 at 10:16 AM
It's almost a real computer now :-)
November 9, 2025 at 3:40 PM
I've seen your soldering :-)
November 8, 2025 at 8:54 PM
Me ! I do ! Me !
November 7, 2025 at 8:45 PM
Please don't do this ! It does nothing except put your posts twice in every ones feeds, which is quite annoying.
November 7, 2025 at 9:40 AM
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 !
November 4, 2025 at 1:19 PM
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.
November 2, 2025 at 2:32 PM
Oh yeah, we've all been there :-)
November 2, 2025 at 2:17 PM
Tut tut, not reading the fine data sheet completely !
November 2, 2025 at 1:41 PM
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 :-)
November 2, 2025 at 11:16 AM
CMake is my weapon of choice these days for C projects, but this seemed ripe for just a simple make file :-)
October 30, 2025 at 9:36 PM
Machine code a.k.a T2 code (as the library programme that reads it is called "T2"). See www.billp.org/ccs/gtp803/g...
A Guide to Programming the 803
www.billp.org
October 30, 2025 at 1:49 PM
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.
October 30, 2025 at 12:01 PM
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.
October 30, 2025 at 11:09 AM
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.
October 30, 2025 at 11:05 AM