Wednesday 29 June 2011

Sometimes rebuilding can take a while...

so I started playing with the previous code and knocked out a chunky scroller whilst I'm at it.



The WIP version I have also has a chessboard zoomer in the background, but it's a bit dodgy (I think my interrupts are overrunning a bit), so I've disabled it for this video. If I can't fix up the interrupts I'll seperate them out into seperate parts, fix the scroll position or find some other workaround.

Oddly enough the chessboard is less dependent on lookup tables than the one I did on the ST (It's generated from scratch) and uses a hell of a lot less rastertime to run. I think for a lot of what I want to do the SMS is more powerful than the ST :)

or it could just be my shoddy 68K assembler abilities...

Wednesday 22 June 2011

I've been playing with some Sega mastersystem coding. So far I've got a toolchain up and running that takes a level-sized bitmap, chunks it up, RLE compresses the columns of of tiledata and lets it run on the mastersystem.



The levelmap and graphics are from 'Edge Grinder' - an 8-bit collaborative project hosted at Format war led by Jason 'TMR' Kelk, and were designed for the C64, which is why all of the coloured pixels are double-width. They could be improved for the mastersystem and it's more liberal palette and 1x1 16 colour graphics mode, but at the moment I'm more concerned with getting the code up and running.

Looking at the Sega Megadrive/genesis it looks like it's pretty much the same technique to get things going there, albeit with nicer graphics and a faster 68000 CPU so when I have enough to be going on with I'm going to port it all across.

The sprites look like hassle though - I'm working with 8 sprites per line of 8 pixels width, as opposed to the 24 pixel wide ones on the C64 so it looks like things might get a little difficult.

Maybe a bit of flicker or creative use of background characters might be in order...

So... what happened?

I started with good intentions, but then the whole financial crisis kicked in and it ended up being impossible for me to find a job in Spain, so I ended up on a flight back to the UK for an interview.

I got the job, returned to Spain to collect my stuff and then started working on graphics drivers which has kept me pretty damn busy until now. So I've ended up doing low-level coding but nothing I can talk about in public.

I've just started finding time to do code in my free time again, so watch this space.