For the ZX Spectrum lovers, there was enough documentation around to also simulate the whole Spectrum PCB with very precise ULA emulation (cross checked with the actual gates implementing it).

Oct 20, 2026 · 9:29 AM UTC

19
24
272
14,365
Replying to @antirez
On my GitHub as usually.
1
0
13
3,877
RepliesRelevant
Replying to @antirez
@antirez yaay - also the book that actually unlocked ULA for everyone!
0
0
6
213
Replying to @antirez
@antirez don't forget to read
0
0
0
53
Replying to @antirez
@antirez Awsome. Here it started with Z80 assembly making my first game when I was 13 yo back in 1983 😀
I miss those days, when you had just 16 KB of memory to work with. Every byte counted!
0
0
2
201
Replying to @antirez
@antireze-level detail exists because one fan cut the chip open. Chris Smith had the Spectrum's custom Ferranti chip stripped down to bare silicon, breaking several machines along the way, then spent about two years tracing it by hand on paper schematics that together ran about two meters wide. His 2010 book even filled a gap in Ferranti's own archive at Manchester's science museum.
0
0
0
76
Replying to @antirez
@antirez we need to reopen the zx spectrume scene, and the embeddoscene needs to get going aster than ever. good thing some inspiring engineers figured it out on their own.
0
0
0
122
Replying to @antirez
@antirez Have you ever tried MiSTer FPGA? These ideas would be amazing on that platform.
0
0
0
34
Replying to @antirez
@antirez cool - was aware of these back in day but was on the Sorcerer then Commodore line
0
0
0
78
Replying to @antirez
@antirez Will you be making simulators for any of the Atari 8-bit systems? Seems a natural target for your developing skillz.
0
0
0
41
Plaid helps AI in finance understand the language of money.
0
2
61
5,850,099
Replying to @antirez
@antirez These should be pretty cool to extend as interactive repair guides for old hardware.
0
0
1
142
Replying to @antirez
@antirez What’s with all this hardware emulation works? Do you want to replace QEMU?
0
0
0
81
Replying to @antirez
@antirez checking it against the real gates is the cool part. did that find any spot where the usual emulators got the ula timing wrong?
0
0
0
126
Replying to @antirez
@antirez love that simulator. what's that? can i put arbitrary layouts?
0
0
0
143
Replying to @antirez
@antirez Love that it's checked against the real gates.
0
0
0
30
Replying to @antirez
@antirez su queste cose non ci capisco una mazza, e' un emulatore?
0
0
0
106
Replying to @antirez
@antirez sei avanti
0
0
0
13