Early bringup of a new old 16 bit second processor for the Beeb... in the form of a C model for the PiTubeDirect. Here's a Pi, a level shifter, a BBC Master, and a green-screen monitor.
A bit more here, in the thread 'retrocomputing during lockdown'
Not a lot, in part because of the strong brands already present, many of them local. And in part because the first shipped MSX machine, from #SpectraVideo, wasn't actually MSX compatible.
See this advert, captioned "When it comes to personal computer SpectraVideo is beyond any compare!"
Perhaps that's what "beyond any compare" means?
All about floppy formats, from the lowest levels. Do you know your FM and MFM? Can compare Apple's #GCR with #Commodore's? Understand the difference between flux density and data bit density? Remain calm while discussing zoned recording and sector gaps? Can you write a track at a time? Can you flip a floppy? These are all important life skills these days, so click through and read André Fachat's treatise, especially the diagrams.
via cbm-hackers list
16-bit #retrocomputing with the 4MHz #Z8000 in the 1983 #Olivetti #M20, a sturdy all-in-one with 160k RAM and noisy 10M hard drive. The B key didn't work, nor did the video. Some refurb later, it ran the SPHERE benchmark, in Olivetti Basic (37697 bytes free), at about 3x the speed of a Beeb. (Mono graphics, 256x512.)
More photos, inside and out:
You can add a colour board, or an x86 card for DOS.
Italy, 1982, #mos6502 SHINE computer, with 16k RAM (expandable to 32k,) 256x192 graphics, 8k Basic, 1771 floppy controller with 4k DOS as an option. (700 thousand Lira, about the same for a floppy expansion, and again for a printer.)
Via Stardot where the machine is run in emulation:
See also a 1981 press release: to launch in January at 600 thousand lira. See p14 of issue 3 of MCmicrocomputer:
Cray-1B, serial number 1, rebuilt for the recent SC18 conference.
The machine was on loan from the Chippewa Computer Museum. Originally installed at Los Alamos but returned to Cray: "When Serial 1 showed up in Los Alamos in 1976 it wouldn’t run for more than a few minutes yet it would run for hours in Minnesota. Turns out there was no memory protection and cosmic events at Los Alamos altitude were different enough from Minnesota."
With a bit of Basic code from hoglet we could catalogue the available CPUs, then got a REPL running and could run a Pi-calculating demo on our RISCy #OPC7 CPU. (Other CPUs: 6502, Z80, x86, 6809, PDP-11, ARM)
What an evening!
Pong chip in the browser! Cole Johnson reverse-engineered General Instruments' AY-3-8500 and put up a visual6502-style simulation. See blog posts near here:
"A simulation of the AY-3-8500 would greatly aid reverse-engineering, bug-fixing, and educational value. It's an excellent specimen of a 1970s-era ASIC. I set out converting Sean Riddle's die photos into a working simulation."
Just over 3000 transistors.
Hat tip @sohkamyung
"So I thought, I'll save a month writing my BASIC, and I'll have a chance to be known as the first one to write a BASIC for the 6502 processor. I said: I'll become famous like Bill Gates if I write it the fastest I could. So I stripped out the floating point."
#woz, on writing Basic for the #mos6502, in this #retrocomputing interview:
(Photo is of course an anachronism!)
This is my retro room, as of a year ago. Things are rather less tidy now. We have here two BBC Micros and a BBC Master, a Sony 5" black and white TV and a monochrome green-phospher monitor, a Z80 second processor cheesewedge (Acorn being wizards back in the day). Also a Sinclair Scientific, a Psion 3 and a sliderule. And some modern gear.
And a few pixels of a Pi-based or FPGA-based second processor too.
Chris' mesmerising remake of the Antikythera Mechanism reaches Episode 9 - and the epicycles are in play! Great explanation of what's going on here: the motion of the moon, and the 2000-year-old mechanical design which models it. And as ever, craftsmanship on display, using (mostly) era-appropriate tooling, much of it made himself. More on the web:
Looking for *Apple II Logo* by the good people at MIT, found this *Apple II in ʟᴇɢᴏ* as a bonus. (Ken Gagne's blog is great:
But recently Lars Brinkhoff found the original source for Apple II Logo:
and on github here:
To assemble it you'll need a PDP-10 running ITS, the venerable Incompatible Timesharing System. Or maybe in emulation.
More discussion and detail:
Dennis Kuschel built a minicomputer with a homebrew TTL CPU - it's an 8 bit CPU with 16 bit address space, but it runs a virtual 16 bit CPU which can run Contiki, a multitasking OS with TCP/IP stack and C compiler. The machine even serves its own website:
Via radicalbrad on the 6502 forums. #retrocomputing
Here I am, in case you're looking for me, as previously seen on Gplus, especially in Retro Computing, and Computer History, and Computer Security & Lockpicking, and Computer Science, Seriously, and Computer History Book Club, and HP Calculators, and others.
#retrocomputing #gplus #pluspora #pdp11 #6502 #bbcmicro
Excellent #SF short story - funny, and full of relevance:
The #Curta mechanical #calculator -
ingenious, famous, and highly desirable. From the gallery of beautiful things at and near
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko