The Apollo Guidance Computer [video + slides]
I re-did an updated version of my part of the Ultimate Apollo Guidance Computer Talk at VCF West 2019.
Visualizing Commodore 1541 Disk Contents – Part 2: Errors
We have previously visualized the physical layout of C64/1541 disks. In order to understand the encoding and potential read errors, it is more useful to visualize the disks sector-by-sector.
Commodore "Video Supergame 64" Bundle
The “Video Supergame 64” is a Commodore 64 bundled with a joystick and three games on a cartridge, sold mainly in Germany in 1988/1989. Here are some pictures.
Dumping Commodore 64/1541 Disks with Errors
Many old Commodore 64/1541 disks have read errors, but this doesn’t mean the data isn’t recoverable – with the right nibtools settings and some cleaning.
Commodore “Magic Voice” Cartridge for C64
“Magic Voice” is an expansion cartridge for the Commodore 64 that can speak 235 predefined words. Here are some pictures.
TopDesk 1.3 GEOS64/128 Original Source
Thanks to Falk Rehwagen and Jürgen Heinisch, the original source of the TopDesk file manager for the GEOS operating system of C64/C128 is available.
Tynemouth Minstrel ZX80 Clone Kit
I have previously shown an unassembled Sinclair ZX81 Kit that could be bought in the early 80s. Today, it is possible to buy a clone of the ZX80 from Tynemouth Software. Here are some pictures.
Converting a Commodore 1541 or 1570 Drive into a 1551
The 1551 is the weird outlier in the family of Commodore disk drives: It is the only drive using the “TCBM” bus instead of Serial or IEEE-488. And what’s even weirder? 1541 and 1570 drives converted into 1551s!
More Original Commodore Source Code
There have been a few new interesting additions to the Commodore Source Code repository, including:
Commodore Peripheral Bus: Part 5: TCBM
In the series about the variants of the Commodore Peripheral Bus family, this article covers the lowest two layers (electrical and byte transfer) of the “TCBM” bus as found on the TED series computers: the C16, C116 and the Plus/4.
Run CP/M on your C64 – using Emulation!
In this episode of computer archeology, we deconstruct a very interesting case of borrowing code from multiple places – but first try this D64 disk image with any Commodore 64 emulator or a real C64:
C64 CP/M Cartridge
The cartridge that makes a C64 a “dual processor” computer: Commodore’s CP/M cartridge for C64 contains a Z80 CPU and comes with version 2.2 of the CP/M operating system. Here are some pictures.
Commodore Bildschirmtext II Decoder Cartridge
Here are some pictures of the outside and the inside of a Commodore Bildschirmtext II Decoder Cartridge for the C64 – a 6800-based computer connected to the expansion port!
Sinclair ZX81 Kit
Here are hi-res photos of an unassembled Sinclair ZX81 kit, with German assembly instructions.
Blue Chip BCD/5.25 Disk Drive
After previously dissecting the firmware of alternate C64 disk drives, let’s now look at the hardware of one: This is the Blue Chip BCD/5.25.
Recovering Files from Broken Amiga OFS Disks
extract-adf is a tool for recovering files from broken Amiga OFS filesystem images. It can reconstruct directory hierarchies even for files that don’t have directory entries.
The Commodore IEEE-488 Cartridge for C64
Commodore 64 disk drives were usually connected through the slow serial bus. This article shows some hi-res photos of the Commodore “IEEE-488 cartridge”, which made the faster PET drives available for the C64.
Final Cartridge III with GEOS
The Final Cartridge III is great: It comes with a disk speeder, BASIC extensions, an excellent monitor – and an impressive, but ultimately useless GUI, because there are practically no applications for it. Let’s replace the FC3 GUI with GEOS!
Boxed MOS 6502 CPU
Back in 1975, you could order a boxed 6502 CPU directly from MOS in Norristown, PA. Here are some high-res photos of such a box and its contents.