Aurelie sound cartridge demo YouTube video by DrRamtop

This is awesome @ramtopretro.bsky.social !

youtu.be/JeNx-OwGDXg

Thought you might be interested in hearing an SN76489 conversion from my NSF converter. Still a work in progress...

My universal converter for the BBC Micro SN76489 now contains support for over 15 PSGs and 20+ different input file formats. Most of the converters have been rewritten from scratch. Here's the latest addition... the .sndh converter that shares code with the .ym and .ay converters now. 🔊

It’s a variation of Nick Jameson‘s 3D graphics library. Still a few extra cycles to be squeezed out of it.

Solid polygons next 😎

I've been working on a universal music converter, and revisiting some older tools to include. Here's a much improved SAA1099 to SN76489 converter that I'm integrating (Any glitches are my rudimentary player). All my converters use an intermediate format before I compress to 3 tone/1 noise channel.

As converting NES .nsf files is very similar to converting .hes files, it didn't take much to add this to the converter. As a bonus I added VRC6 support too so I could convert some of the tracks from Castlevania 3 - Dracula's Curse JP. Need to find a good source of new modern .nsf files now. 🔊

Continuing my PC Engine HuC6280 to BBC Micro SN76489 converter. I've added support for .HES / .m3u files as input which expands the available content for conversion. It also tries to intelligently compress the channels down to three tone and one noise. Not too bad so far. 🔊

I've been working on a new HuC6280 (PC Engine/TurboGrafx-16) to BBC Micro SN76489 converter. Quite a challenge to fit 6 channels into 3, but trying a new technique with arpeggiation. 🔊

Trying out some visualisation effects in the player, making better use of the space and moving the track metadata into the scroll text. Broken a few things along the way, but so far working okay even with the software bass active. Now to reduce the number of cycles it takes to display. 🔊

Acorn Electron版 AWASS #acornelectron
inufuto.web.fc2.com/8bit/awass/#...

I thought I'd give the Acorn Electron port of the Squeeker Plus 1-bit engine a go, not expecting much considering the demands on the faster BBC Micro. However, venturing into the murky realms of illegal NMOS 6502 op codes, it's playing!.... badly, but it's at least recognisable with its issues.

A bit of an improvement... pitch is now right, and track length matches the ZX Spectrum version. Drums, however, are still way off...

Very much a work in progress, but quite a while ago @h0ffman.bsky.social shared his .1tm file for 1-Bit High and Rising. The intention was to port the Z80 Squeeker Plus engine to the 6502, but it proved to be difficult... until now.

Pitch is wrong.... but it's finally playing . More work to do! 😊

I think it’s most likely a combination of poor choice on my part using Mode 5 with double width pixels, rounding errors and orthogonal projection. I have a version that implements perspective but broke the backface culling.

Today's demo effect on the BBC Micro... the iconic spinning cube. Here's a very basic version with backface culling. I wasted 10kb on double buffering, so there's only room for a short sound loop on this one. There are much better spinning cube examples already on the Beeb. 🔊

Today we have a classic scroller on the BBC Micro with a slight twist... custom font scaled dynamically to 16x16 pixels and continuous gradient applied to give the impression of more colours than supported by Mode 5. All software scrolling (no CRTC abuse) so works on the Acorn Electron too. 🔊

Another attempt at a BBC Micro Mode 7 demo effect today - the Moiré pattern. Could do with some colour and further optimization, but just wanted to get the basic effect working. This demo is accompanied by some classic Mad Max {Jochen Hippel) music. 🔊

#bbcmicro #demoscene

Thanks. I‘m going to have to get my head around vertical rupture at some point, but putting that off for now. I’ve a few other effects I want to try first and then I may return to the CRTC. So far the effects haven’t been too timing critical so music with software bass works with them.

More 6845 CRTC experimentation on the BBC Micro. This time it's Mode 1 and an infinite vertical scroller. I'm probably not doing this right as it's not as smooth as I would expect. Need to do some more reading on this one. No music with this demo.

#bbcmicro #demoscene

Experimenting with the BBC Micro's 6845 CRTC to do some smooth full screen hardware scrolling. Not something I've attempted before and I can see a number of possibilities. This is a simple Mode 5 dynamically generated gradient that I'd have a lot of difficulty moving at this speed in software. 🔊

Today's demo effect on the BBC Micro... water ripples. This would be much better in higher resolution so I may try a Mode 1 or 5 version. It doesn't quite follow the original algorithm due to the resolution constraints. 🔊

#bbcmicro #demoscene

Another demo effect on the BBC Micro with music... it was going to be a dot tunnel demo but I haven't yet got the tunnel effect working, so here's a variant. 🔊

#bbcmicro #demoscene

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. 🔊

No, it’s Mode 4. Placeholder background at the moment.

XOR’d direct to screen memory

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. :-)