Today's BBC Micro demo effect.... it was going to be a rotozoom, but I can't get the rotation looking right or at a reasonable speed at the moment, so here's a panning, zooming checkerboard with music. 🔊

Experimenting with trying to recreate some classic demo effects on the BBC Micro, starting with plasma. The version I have in Mode 5 looks better, but was slide show speed so moved to Mode 7. Needs more optimization, and the plasma effect can be improved. Added some music too. 🔊

Ok, this is about as complete as it will get 😊 Here's a preview... I'll tidy up a few things (maybe change the music) and post on Stardot. 🔊

Stage 2... need to optimize the snow fall some more, and then add the interrupt-driven music. 🎅

Not sure where I'm going with this yet, but I'm determined to make a little festive demo for the Acorn Electron. I have some music ready. Watch this space. :-)

I've released a beta of the first BBC Micro David Whittaker Music Disk here: www.stardot.org.uk/forums/viewt... Looking to get some feedback on compatibility with real hardware before I publish the final version to my website. Still may be one or two small bugs to fix.

I now have the ability to use 16kb of main memory if no SWRAM is present on the device, so those without at least get to hear songs that fit into that space and partial songs from those that don't. This also works for songs where you don't have enough SWRAM banks to fit the whole track.

Getting closer to releasing a whole batch of music disks I've put together for the BBC Micro. Spending some time on cycle-optimising the music driver as even two or three cycles make a difference when called in the main play loop. At the moment it requires SWRAM - about to fix that...

Here's a hint where I'm going with this sample sequencer. I've moved the playback loop to zero page and leave the WE (write enable) active which allows output of 16kHz samples (although memory becomes an issue). Need to combine this with my SN76489 conversion of the SID.

Just a little something I'm working on. This is RLE encoded for fast playback, but I'm sure I can compress the samples better to fit more in memory / SWRAM.

Some further progress! The ROM version of Speech! is now working on the Acorn Electron. The speed difference, and hence the quality of the sound, is quite dramatic. Hopefully that's the whole disk and demo programs converted now. I'll package this up properly and post a link on Stardot.

Acorn Electron Speech! Here’s a work in progress build for you all to try on @0xc0de.bsky.social ’s excellent emulator. Not sure the SWRAM version works yet, so load option 1, then CHAIN “DEMO” or reboot the disk. 0xc0de6502.github.io/electroniq/?...

Getting better... here's the official Speech! demo converted to Mode 6 on the Acorn Electron. This is still just using main memory. No speed up from SWRAM yet.

Well... it sort of works 😊 A lot of optimization needed, but I have a full disassembly that compiles to a byte identical binary and is relocatable. Speech! on the BBC Micro uses 4-bit values for attenuation, which I have to reduce to 1-bit on the Acorn Electron so quite a bit of fidelity is lost.

A release soon 😊. Still finding uninitialized memory bugs causing random crashes... but getting there...

So, three double sided disks of tracked music conversions to the BBC Micro's SN76489 are ready. Just testing that I've fixed the random crash in the player when switching tracks, and then I'll put them up on my website. Works on both Model B and Master, but requires several banks of SWRAM.

I've always wanted to put together a simple demo effect with some background music. I've never got around to this until now. Probably the most basic Sinus Scroller you'll see, with character based positioning. Hopefully I'll improve this over time and use bitmaps. Might even add a starfield :-)

Back in 1987, Your Sinclair published a type-in listing by Tim Follin titled Star Tip 2. It was a 1-bit beeper tune. Recently David Given ported this to 6502 assembler for the Commodore PET. Hence porting this to the BBC Micro was straightforward. It's not perfect, but I'll continue to tune it.

I'm back looking at 1-bit music engines again as I want to port a few others over from the Z80. First I thought I'd revisit the SquatM engine and see if I could optimise it. The first improvement was to get the sound playing on all three tone channels of the BBC Micro's SN76489.

An SN76489 conversion of a new @h0ffman.bsky.social track from @gordon.plus's Oric demo, No Sleep 'Til Budleigh - 2nd in Old School Demo at Nova 2025. As this was converted via the Euphoria emulator in DOSBox, it won't sound 100% accurate (easier to convert .pt3 files). demozoo.org/productions/...

Another bug squashed, and now the player is working consistently on the BBC Micro and BBC Master without screen corruption or crashing. Need to soak test it for a few hours, but close now to releasing two double sided music disks of demo scene conversions.

A few more fixes so the player navigation is stable. Hopefully I can get to a point where I can release some music disks of demoscene conversions soon. Here's another SN76489 conversion you may be familiar with...

Back to working on my BBC Micro SN76489 music player. Squashed a few bugs... introduced a few new ones 😊 Made some useful optimisations on the LZSS decoder which saves a number of cycles every frame. Here's a track that may sound vaguely familiar...

A work in progress. Can't leave the enhanced version of Elite on the Electron without music ;-) Using the original MIDI tracks by Aiden Bell as the source: www.dream-ware.co.uk/elite/music/ Difficult to compress into a single channel with no volume control! 0xc0de6502.github.io/electroniq/?...

I’ve been working on more sound chip file format tools and this one’s just about ready for its first release. It converts ZX Spectrum .AY files (AY-3-8912 only… not beeper) to separate Atari YM6 .ym files. I have another converter I’ll release soon from YM to VGM. github.com/NegativeChar...

Here's a very early preview of the output from my Amiga MOD to SN76489 converter. The basics are there (most of the effects), but a lot is still incorrect... playback is too slow, FFT detection of tone versus percussion isn't 100% accurate, and there's no attempt to emulate drums. But, it lives...

An early preview of a new Amiga MOD to SN76489 PSG converter I'm working on. No sound on this video, but the output so far is better than I expected despite not using the sample data at all. Next step is to do some basic FFT to determine percussion from tones.

Home Arcade is a brilliant new album from LukHash, and the pre-order came with two bonus C64 SIDs and an Amiga MOD. Now listening to SN76489 conversions of those SIDs on the BBC Micro 😎

The basis of another converter created.... this time MIDI to SN76489. It handles type 0 and 1, and has pretty much managed everything I've thrown at it. Even has rudimentary ADSR simulation. Opens up a huge range of tracks I can now playback on the BBC Micro... well 4 of the channels anyway.

Taking a break from developing the YM2151 converter to have a go at another sound chip I've wanted to try for a while... the PC Engine's HuC6280. Here's the first attempt at a converter to the SN76489. Not bad so far! This track's from Daimakaimura (Ghouls 'n Ghosts)... The Haunted Graveyard.

Making progress on the YM2151 to SN76489 converter. Still no drums, but all channels decoding now. Volumes aren't right yet, and note on/off isn't perfect, but more YM2151 tracks are converting now. The one problem... I'll need at least 3 SN76489 chips to play this one.

I must admit I'm sceptical of the ability of AI, but am impressed at the YM2151 to SN76489 it created for me. No drums yet (converting Sega PCM to SN76489 noise is its next challenge). It needed a lot of prompting and feeding of specs and formulas, but eventually I had the following conversion.

I think I’ll be trying this out tonight: github.com/tildearrow/f...

Just fixed a major bug in my Atari ST SNDH to SN76489 converter. This fixes stretching of tracks when sampling the YM2149F registers at high rates. Watch the square waves dance at around 0:38s in... Now to get real hardware to do this 😎 Track is Grand Theft Auto IV by !Cube

Here's a BBC Micro SN76489 conversion of @warlord-phobos.bsky.social 's excellent C64 SID track 'Battle Against Fatigue'. Hear the original on Soundcloud: m.soundcloud.com/armagon/warl...

Great to see we can now upload 3 minute videos! Here's another track from the double BBC Micro music disk I'm putting together - a 4 channel SN76489 conversion of Starshine by Purple Motion.

31 tracks converted for my next set of BBC Micro music disks of tracked music, including this one.... a classic from Romeo Knight on the Amiga:

I'm putting together another tracked music conversions album for the BBC Micro... an mix of old and new. Here's Enigma-Gun by Romeo Knight from 1990 converted to the SN76489.

New BBC Micro music by Enfys... joint 2nd in the MountainBytes 2025 Combined Music competition at the weekend. Great tune!

SSD updated with 7 additional tracks for you to try. Still a few bugs in the converter when the original track runs off an arbitrary interrupt, but not bad from the Electron with its lack of volume and single channel beeper. 0xc0de6502.github.io/electroniq/?...

Trying to out the excellent Electron emulator by @0xc0de.bsky.social Putting its sound capabilities to the test: 0xc0de6502.github.io/electroniq/?...

Another IBM PC PIT to Acorn Electron ULA conversion. This one needed the lower tones to be transposed an octave.

A small fix to my IBM PC PIT to Acorn Electron ULA converter, and now this one works...

Thought I'd go back and revisit the Acorn Electron music driver and player. It shares some of the setup code from the BBC driver so there's a few improvements I can make. Still limited to 50hz and 100hz playback without resorting to cycle counting.

Working on something special related to YM2149/AY-3-8912 playback on the SN76489 using interrupts. In the meantime here's a Jochen Hippel track I haven't converted before, enhanced with software bass.

Haven't had a lot of free time recently to post, but here's a preview of a track from a couple of disks I've put together of BBC Micro conversions of 4mat tracks from various 8-bit and 16-bit platforms. Even includes a few from my experimental Amiga MOD to SN76489 converter using FFT.

Here’s a music disk for the BBC Micro full of 30 Ben Daglish conversions from various 8/16-bit platforms. If you take a copy of the .dsd to run on your own hardware, it needs at least 3 banks of 16kb SWRAM. The link below to plays in Virtual Beeb: negativecharge.github.io/virtualbeeb/... Enjoy!

Putting together a few more music disks for the BBC Micro, while exercising the driver's software bass. This Ben Daglish track sounds nothing like the usual sound you'd hear from the SN76489. Still tracking down a visual bug in the player - issue is only with a Model B...Master is fine.

Still a few bugs in BBC Micro music player I’m working on (mainly graphical glitches), but it’s now in a usable state. Check it out via Virtual Beeb here: negativecharge.github.io/virtualbeeb/... If you try the .dsd on your own hardware, please let me know if the SWRAM detection works for you.