Cropped iPhone screenshot showing a hex-view of “48.rom”. Two consecutive bytes among many are highlighted. (Other fondleslabs may be available, YMMV).
Holy hexadecimal Batman! Evidently they make hex editors for Trouserphones now, so you can scrutinise the ZX Spectrum ROM code on-the-go! (Or indeed, on-the-couch).
LT6502: a 6502-based laptop design
#gamedevelopment #indiedev #gamedev
Paula Maddox's LT6502 is a modern laptop design based on the retro 6502 microprocessor: github.com/TechPaula/LT...
#csharp enums in conjunction with the Flags attribute can be a powerful tool when working with #bitfields.
Discover two examples of how I used them to make my 6502 microprocessor #emulator code easier to reason about:
markjames.dev/blog/bit-mas...
#dotnet
Keyboards laying in a snowbank.
Spotted an IBM #ModelM laying in a snowbank while running errands earlier this afternoon.
#retrocomputing #vintagecomputing #mechanicalkeyboard #vintagetech
OpenSky.NET is a #dotnet library that I’ve been developing for interacting with the #OpenSky Network REST API.
#ads-b #airplanes #atc #adsb #flarm #aviation #mode-s #vhf
github.com/markjamesm/O...
New blog post: Remote diagnosing a PET 2001 video fault from one photograph.
blog.tynemouthsoftware.co.uk/2026/02/diag...
Includes a look at how the PET video system works with redrawn schematics.
It also turns out to be a surprisingly early PET 2001.
A die photo of the 8087 chip, with the main functional blocks labeled. The chip is a tan rectangle with complex patterns in dark brown. Many of the patterned regions are textured rectangles. One of the largest rectangles is the microcode ROM in the middle. The bottom half of the chip is the datapath, performing operations on floating-point numbers. The instruction decoding happens in the upper left. Around the edges of the chip, bond wires connect the chip to the 40 external pins, but the pins are not visible, just short segments of the bond wires.
In 1980, Intel released the 8087 floating-point chip, making math much faster. I'm reverse-engineering this chip, 46 years later. Most of its instructions are implemented in microcode, but some are implemented in hardware. Let's look at the circuitry that decodes instructions and decides what to do.
Screenshot of the MusicSharp interface.
MusicSharp is an #opensource, cross-platform #TUI music player that I developed using C#. A fully standalone application (no #dotnet runtime required), it supports MP3, FLAC, WAV, & internet radio streams!
There’s still more work to be done, so feel free to contribute!
github.com/markjamesm/M...
New Ancient DOS Games episode uploaded and ready to watch! youtu.be/ADZKPcsbOX0
Do you like SimCity 2000? So do we! I'm pleased to announce that the tenth major release of sc2kfix is available with a whole host of new features and bugfixes, including FluidSynth MIDI output, SCURK functionality on Windows 11, preliminary modding support, and much more: github.com/sc2kfix/sc2k...
Comparing the output of my emulator to test data for the jump indirect instruction JMP ($70FF)
I’ve been developing an #emulator for the MOS 6502 and ran into a hardware bug that occurs when a page boundary is crossed during the jump indirect instruction.
Check out my article on the bug & how you can handle it when emulating!
markjames.dev/blog/6502-ju...
#retrocomputing #emulation
Screenshot of Chippy, a CHIP-8 emulator running the Timendus CHIP-8 Test Suite.
Several months ago, I became interested in emulation, and it led to me developing Chippy, a CHIP-8 emulator written in C#.
Check out the source code on GitHub:
github.com/markjamesm/C...
#emulation #softwaredevelopment #programming #chip-8 #chip8
