Workprint – September 2018

I spent the previous weekend visiting family dahn sarf and, after a particularly harrowing coach trip home, had to spend a few days “recovering” so this post is a bit later than expected… on the plus side, I picked up a copy of Compute’s First Book Of Atari Graphics from the lovely folks at Level Up in Canterbury…

…which I hope is not too advanced for me! It even came with a hand-written page – poking out of the book in the picture above – of display lists as decimal from a previous owner which seems to have been used as a bookmark since it’s a few pages into the chapter titled Introduction To Player/Missile Graphics, one of the few places where the display list isn’t particularly relevant.

Sorry, drifted off a little there… so I’ve been working on the project I’m still not really talking about, although it’s probably safe to say I’ve been a little lazy recently; the intro is done and there’s two complete parts still waiting to be linked, but I haven’t found the time for a prolonged coding session to get any of that done and it’s one of those jobs I don’t want to stop halfway through for fear of losing my place. I also have a list of potential ideas which is coming along nicely and a couple of existing prototypes which can be improved and re-purposed so stuff is still happening.

I did find a couple of hours to doodle some code whilst away though; an interesting thread at the Plus/4 World forums mentioned using the registers $FF1A and $FF1B to scroll a bitmapped screen around in a form similar to AGSP on the C64 except without the “dead air” at the top of the screen, so I spent some time experimenting to get my head around it. The code I wrote works but this method only affects the bitmap itself so colour data would need to be moved by brute force, a bit of an ask considering the Plus/4 uses 2K for bitmapped graphics regardless of mode. It’s something to experiment with later, although I’m seeing an odd, almost FLI-like glitch in the version I wrote which added splits for a character-based scrolling message and can’t think for the life of me why it’d be there!

Workprint – August 2018

As noted a few times recently, I’ve cycled over into “demo mode” and have been working on… well, something that I’ll be keeping quiet about for a little while yet until it properly gets past that stage where it could be changed or indeed completely reinvented on a whim. Generally speaking though, my intention is to have something ready for X’2018 in early November – assuming we have a representative to take it along – and have a cluster of prototype routines along with some other ideas I’ve been meaning to try and a folder of logos because everybody loves logos… right?

Things have been going slowly but surely so far – today alone I somehow managed to metaphorically paint myself into a corner on two different occasions with what should’ve been relatively simple code, either choosing a less than sensible place to store things or simply running out of memory altogether – and, because it’s been a painfully long time since I worked on anything that wasn’t a onefiler, last week saw me sitting down and trying to get my head around cruncher and loader integration with some of the more recent iterations of popular tools with very little joy… at least until I discovered lft’s Spindle that is.

Spindle is, in essence, a back engine for demos which deals with loading and decompressing of data to the point where the user doesn’t need to be involved; no fighting assemblers to build loader or decruncher code, no messing around with building disk images of data, just document the files being used and the order they’re needed via a script file which is then run through Spindle to automagically get a working disk image out the far end. There are caveats of course – a couple of places in memory have to be avoided, something else I bumped into today – but having to do things just a teensy bit differently is worth it for the results.

Main project aside, there’s also been a little time spent generally doodling both with graphics and ideas for effects and a couple of forays onto other platforms; something might come of the latter if they survive testing on real hardware – in both cases the code was for a platform I don’t actually own right now, so that’s something of an issue – but at the very least it was all good practice.

Workprint – July 2018

Things have been a little rough of late with everything being topped off with our thirteen-year-old dog King passing away on the 7th of June – he arrived here at the start of 2005 as a small, six week old bundle of fluff. I haven’t really been in a fit state for much of anything since then – I pretty much kept up with Retro Gamer and tried “powering through” and sticking to my blog schedules but only managed about half of the “planned” posts – and I was even quieter than usual on social media which is something of an achievement I suppose? I’ve just realised whilst writing this that it happened almost a month ago, but I’m still getting the occasional wobble when it would have been his dinner time…

I haven’t done much code since then, but the bulk of what I’ve written during that period has been “busy work” to keep my mind occupied more than anything else. Vallation hasn’t seen any attention because I didn’t dare sit down with anything that complicated where I could easily lose concentration halfway through modifying something important and leave myself with a steaming mess to knock the bugs out of later… I’m perfectly capable of doing things like that often enough as it is without any external encouragement!

One of the distractions was writing a game for the Spectrum for release under the C64CD brand. It’s pretty much done apart from needing quite a bit more level data, but now it’s that close to complete I’m sort of committed to finishing it as an entry for the venerable CSS Crap Game Competition. It’s crap in the sense that it’s incredibly simple as a game and my Z80 is shockingly bad to the point where I’m considering a disclaimer when the source goes up to Github warning people that it’s not there as a “learning tool” unless being used as an example of how things really shouldn’t be done. That doesn’t stop me being almost perversely proud of it for some reason?