Another release so soon? MD201706 is merely a plotter with some cosmetic niceness, but the code is a little unusual; it needs a SuperCPU (which can be emulated in recent versions of VICE and, unless it’s lying, it should run on either PAL or NTSC) or the Turbo Chameleon set to 6MHz or faster in order to run. Its single buffered and can clear, update and draw four hundred points a frame courtesy of the expansion hardware. It isn’t fully using the capacity of either device, the current firmware of Chameleon with its speed set to “no limit” is slightly faster than the SuperCPU but I restricted myself to 6MHz in case that top speed changes downwards with future updates.
A few people are probably going to ask “why” and the simple answer is “because”, but I’d actually been prodding around my unrolled plotter which was used in MD201704 on the C128, using 2MHz mode in the borders and found myself wondering just what my Turbo Chameleon could do with it. Then Wolf 3D for the SuperCPU arrived and I decided to make my code run with both. As always, GitHub is the source for… erm, the source and questions can be passed on in the usual manner.
This is probably going to be the end of season two for the Monthly Demo series because I want to take a little break to work on games… and yes, I’m already braced for the influx of responses that’ll probably get, so will be running away before this post goes out!
Two releases for the price of one this time, although they’re built on the same block of scroller code. WannaCrypt for the C64 and Atari 8-bit is a teensy demo with a loose copy of the WannaCrypt decryption tool and a scrolling message which is, due to a discussion about simple encryption at the Atari Age forums, reversibly mangled using a couple of simple techniques. Here’s the C64 version which features an old but still golden tune composed by Marc “Skywave” Francois…
…and this is what it looks like on the Atari 8-bit with graphical help from José Pereira and accompanied by Miker on the POKEY. There are even vertical colour splits being used on this one!
The source code for both the C64 and Atari 8-bit versions are available at GitHub, although they don’t come with the painfully hacky BlitzMax tool which takes some text and creates a mashed up binary file.
There hasn’t been a lot of coding time for one reason or another recently, but one thing I’ve been tinkering with a little is the SuperCPU or more accurately an emulated version courtesy of VICE; I’ve reworked my unrolled plotter – the one used in MD201704 – to handle about four hundred points. There’s also a “user interface” so that the cosine curves can be fiddled with as well because that seemed like a fun thing to do.
Halfway through playing with it I realised that, since it’s 6502 code rather than 65816, there’s no reason it won’t work on my Turbo Chameleon-equipped machine as well… where the 6MHz mode takes longer to get all of those points cleared, updated and drawn whilst the “unlimited” mode actually gets job done faster than the SuperCPU! Since I can at least release it as tested on one real accelerator and possibly get someone to run it on a SuperCPU as well, this may well become MD201706 and there should be enough raster time to finally use Sean’s double speed cover of Brian The Lion without breaking a virtual sweat.
There’s also a C64CD demo being prodded at right now, quite literally in fact since it’s testing on my C64C as I write. Unlike previous releases on said label it isn’t inspired by classic 1980s or 1990s releases and instead has a loose theme based on current events and a discussion at the Atari Age forums which got onto the subject of encryption. It needs a little more work, but should be ready to go either tomorrow or possibly Thursday.