Archive for the 'Release' Category


If you’ve accessed BDOS-format disks in Windows, you’re probably aware of the need to run with Administrator rights. For security reasons, raw disk devices cannot be opened by normal unprivileged users. Starting with Windows Vista, processes are launched with basic rights, even if the current user is a member of the Administrators group. To run […]

TrinLoad v1.0

Developing Trinity-specific code has typically meant assembling directly on real SAM hardware, or assembling on the PC and transferring the program over to SAM. In my case the latter involved writing the disk image out from pyz80 to an SD card using SAMdisk, moving the card over to Trinity, rebooting SAM to have the new […]

Spectrum Snapshot Tracing

Given a Spectrum snapshot, is it possible to determine which areas are code? A typical approach would be to modify an emulator to record the location of every instruction executed, and let the snapshot run normally for a while. This gives a guarantee about marked locations, but it’s limited to code that is actually run […]

Space Invaders emulator

I thought it was about time I added the Space Invaders “emulator” (binary port?) to my website, as I’d not touched it in over 3 years. Most of the work to get it running was done, with just sound and display rotation left to add. While mulling over the tricky display code I moved on […]

Apple 1 emulator

This will probably be my last emulator for a while so I can return to normal projects. I’d wanted to emulate the Apple 1 for quite a while, and didn’t think it should take more than a couple of hours to make a usable emulator. The Apple 1 is a surprisingly simple device, with 1MHz […]

Orao emulator

This emulator started as a quick test of my 6502 core, to see if it could run the Orao ROMs. I half expected it to fail due to lack of decimal mode or interrupt support, neither of which were implemented in the SID player core. It took just 20 minutes of hacking the SID player […]

Galaksija emulator

I’ve spent most of the last week porting Tomaz Kac’s Galaksija emulator from Spectrum to SAM, with version 1.0 now available on my site. Basic SAM support was trivial, requiring just an OUT to LMPR to page in the ROMs, and another OUT to VMPR to set video mode 1. The Spectrum key matrix is […]

FdInstall revamped

I’ve spent the last few days updating FdInstall, which is used to install/uninstall/upgrade fdrawcmd.sys. It needed a few improvements for Vista support, which gave the perfect excuse for a complete revamp. The original installer was designed to have minimal dependencies, be simple to use, and avoid reboots where possible. I went for a single dialog […]