Black Rock

Texas Instruments SR60A Repair(s) Quite a while ago I finally saw one of these machines on ebay.

Recreating OPL The Psion Organiser II came with an on-board programming language called OPL.

Making and Populating a Raspberry Pi CM4IO PCB RP CM4 The RP CM4 (https://datasheets.raspberrypi.com/cm4/cm4-datasheet.pdf) is a small processing unit capable of running Linux.

Stainless Steel Sewing Kit Quite a while ago I bought a stainless steel cigar tube with no real idea what I'd use it for.

What do you do if you want to dump the ROM in some equipment that is owned by someone else, who is happy to have their ROMs dumped, but who live in another country?

This One Got Away From Me a Bit...

Pens, Scutoids and a Box A combination of biology and mathematics was the theme for a recent pen box.

Coding With Rules of Thumb I create code quite a bit and have fallen into a process of using 'Rules of Thumb' or 'Meta Patterns ' when doing this.

Chinese Questions It's always a good idea to have descriptive labels when coding, it is extra information that is useful for code comprehension.

Code Comprehension Surely it's better to write this: romdata[addr-0x8000] = v1; romdata[(addr-0x8000)+1] = v2; like this: romdata[(addr-0x8000)+0] = v1; romdata[(addr-0x8000)+1] = v2; Ok, it's a bit more typing but it's easier to understand, surely?

Code the Specification: 6303 Assembler in 2000 Lines of Tcl Using Regular Expressions I have been interfacing to the Psion Organiser 2 recently, firstly using a Raspberry Pi RP2040 to replace a datapack and provide SD card storage of pack images: and also…

How fast is a Modern Microcontroller?

Transputer: Stack Based With OS in Hardware Picoputer: RP Pico Hardware Transputer The transputer was and still is an odd beast.

Reverse Engineering an LCD Display I have a DAB radio which started to irritate me in various ways.

Re-using a Broken Television as a Monitor or What To Do With a Broken Television when You Can't Fix It I was given a broken television.

Miele Induction Hob Problems 2.0 The Miele hob has gone wrong again.

Novena Laptop Fix I got a Novena laptop from Crowd Supply several years ago.

Battery Leakage Again A recent purchase: It's a Casio FX502P in pretty much perfect cosmetic condition.

Using a Thermal Printer Mechanism The Casio CP-10 is a neat calculator that has a thermal printer attached.

Finite State Machines and the Software Hammer The firmware that runs the Casio FX502P gadget that I recently created has a structure and uses a technique that I though was worth documenting.

Casio FX-502P SD Card Gadget Prototype A while back I made a gadget that attached to a Casio FX-502P via an FA-1 and stored programs and data on an SD card instead of a cassette . https://trochilidae.blogspot.com/2017/06/fx502p-cassette-interface.html It…

Casio CQ-1 Recreation Information Until I tidy up the github repository, here's some snippets relating to the Casio CQ-1 recreation.

Reverse Engineering at -17V and 200kHz Warning: Rabbit Holes ahead I have a Rockwell 920/3 calculator.

All This to Get Back Where It Started Storing scrap PCBs is all well and good but what do you do with them?

Is This the Past, or the Future?