Posts Tagged ‘code’

Workprint – July 2017

Wednesday, July 12th, 2017

Yes I’m running late with the workprint post again (or perhaps I should say “as usual”) but, now that I’ve settled back into playing with game code, there’s been some time over the last couple of weeks spent dabbling with Z80 and quite a bit of head scratching about how to do software sprites; I’ve got a sort of working routine on the Spectrum which lacks proper X movement right now, but a lot more thought is required because it can only deal with three or at a push four objects per frame that are ten by ten pixels. That’s crappy and I know the problem is down to my Z80 “skills” being tragically weak, although another project that shall remain nameless for the moment has recently taught me a few things that might help.

On the 6502 front, I’ve been doing a few tweaks to Hammer Down that have been pending for ages so that’s slowly creeping forwards. There’s also the option of doing a small, reasonably well documented C64 game perhaps under the Backward Engineering label (since it hasn’t seen action for a while) to release via C64CD but I haven’t decided what exactly. My “default setting” is a scrolling shooter of course and part of me is tempted to write something with a simplified attack wave engine similar to the one in Ash & Dave’s Pirates In Hyperspace where the enemies have speed values for X and Y which all get changed when a timer expires. C64CD releases are meant to be simple so should I boil the design down to the bare minimum like that or do something a little more involved I wonder? Again, further mental gymnastics are needed…

Workprint – June 2017

Tuesday, June 13th, 2017

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.

Workprint – May 2017

Saturday, May 13th, 2017

I’m completely messed up this month due to the web server spluttering and screwing its boot drive’s file system (did I lose a workprint from last month or just forget…?) and going through the final preparations for getting married in a week’s time so the workprint is rather late! And yes, I’m lightly terrified about getting hitched, the lack of throughput on this ‘ere blog should indicate that I’m not particularly comfortable with being in the limelight!

The post about the April instalment in the release was lost so I might as well bundle it in here so there’s a pretty screenshot to look at! MD201704 was for the Commodore 128 and used 2MHz mode in the upper and lower borders to get sixteen pixel wide colour splits. The inspiration came from seeing Rabenauge’s Elvis Copper on the Revision 2017 Twitch stream and wondering why the colour splits on their demo were so wide with only two distinct colours per scanline. Since I’d been playing with a four cycle wide splitter with three colour values and 2MHz enabled on the C128 anyway, that code was brought forward and overhauled to install the plotter and scroller.

Speaking of Revision, have a look at Ninja Dev’s What Are You Syncing About? because it’s a lovely piece of work – there’s no chance of any machine at Chez Roundabout running it without the result being more a slideshow than a demo, but that link goes to the YouTube video I’ve been trying to wear out.

Finally, the workprint itself and, as noted, spare time is a little more scarce this month but I’ve managed to get MD201705 on the C64 mostly written with just a couple of cosmetic features and the scroll text left on my “to do” list. Basically it’s a reworking of something I’ve done previously with a few extra tweaks and a little more colour, but I’m quite pleased with the results and it should turn up at some point either next week or possibly the week after depending on what I’ll amuse myself by calling “my schedule”.