|
Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment. |
|
Thread Tools |
20th Apr 2022, 9:37 pm | #1 |
Tetrode
Join Date: May 2021
Location: Titz, Germany.
Posts: 72
|
Source code for NIBL recovered
Hello,
finally I finished recovering the source code for NIBL. There are three versions: The one published in Dr. Dobbs, the one distributed as ROM and NIBL-E. You get get them from: http://www.moria.de/tech/scmp/software/ The way NIBL-E was changed and the mention of 300 patches makes me think the binary ROM was patched, so this is the first chance to look at source diffs. Michael |
21st Apr 2022, 11:43 am | #2 |
Octode
Join Date: Mar 2011
Location: North Yorkshire, UK.
Posts: 1,087
|
Re: Source code for NIBL recovered
Thanks for that Michael, I will study that later. I've recently re-read the Dr Dobbs article so your work is very timely! In the "Mystery Book" there is a section on relocating NIBL, but it lists only 27 changes. Perhaps NIBL-E was substantially modified beyond just relocation?
Cheers Phil |
21st Apr 2022, 3:25 pm | #3 |
Octode
Join Date: Mar 2011
Location: North Yorkshire, UK.
Posts: 1,087
|
Re: Source code for NIBL recovered
Spotted a typo in "readme.txt" in the nibl.tar.gz file Michael,
"NIBL-19761217.asm: Source for published NIBL ROM with minimal changes for assembling with asl. Communication runs at 50 baud with a SC/MP II @ 4 MHz. Characters are echoed with the MSB set" That sounded odd so I checked the NIBL-19761217.asm source, & its 110 baud (at 4mhz), not 50 In the Elektor NIBLE source, PUTC and GECO are 110 at 2mhz Cheers Phil Last edited by Phil__G; 21st Apr 2022 at 3:37 pm. |
21st Apr 2022, 7:01 pm | #4 |
Tetrode
Join Date: May 2021
Location: Titz, Germany.
Posts: 72
|
Re: Source code for NIBL recovered
Thanks for the fix, I changed that. I also include that PDF, which I never saw before. What is the "Mystery book"?
The Elektor article on NIBL-E describes a different startup behaviour and there is a tiny function at the end which returns to NIBL the way a machine language function does to allow returning from Elbug to NIBL, but other than that I did not see much besides the relocation itself. Now you have the source and can compare it yourself. I did not yet adapt the NIBL-E source comments to the code changes, feel free to send any changes. Michael |
21st Apr 2022, 7:51 pm | #5 | |
Octode
Join Date: Mar 2011
Location: North Yorkshire, UK.
Posts: 1,087
|
Re: Source code for NIBL recovered
Quote:
which it transpired was "How to design, build & program your own advanced working computer system" |
|