Playing Chronos (Spectrum)

Before I start there’s a little wallowing in nostalgia to get out of the way; during my “formative years” I was primarily a 6502 bunny so never actually owned a Spectrum, but I did get a chance to play on one occasionally when visiting school friends. The first time I played Chronos would have been either 1987 when it was released or perhaps 1988 at my friend Simon Probert’s house and we spent quite a while taking turns at the keyboard to work through and eventually loop it.

To use its full title for a moment, Chronos: A Tapestry Of Time is a horizontally scrolling shoot ’em up from cheap software purveyors Mastertronic, was developed by John and Steven Tatlock – who were also behind the Agent X games – and features a stunning piece of beeper-powered title music from Tim Follin. The cassette inlay also has that “edgy” cover art style that Mastertronic were going for at the time with lots of “exciting” arrows and “torn” edges which was, presumably, considered to be “down with the kids” in the mid to late 1980s.

Turning to the game, things start of relatively sedately with just two randomly spawned nasties in play that travel across the playfield horizontally at different speeds but each new stage introduces another enemy type. Some of these can be little scumbags to, especially during the parts of the map where there isn’t much room to manoeuvre; the squares and Yin-Yangs in particular can suddenly change direction and twonk the player without much warning so really need to be managed before they get the chance.

There’s also a few places where the ground defences are positioned so the player can’t destroy them, forcing some dodging between laser beams as they toggle states or randomly timed streams of bullets. Whilst that can be sometimes frustrating the game makes up for it by being generous with the extra lives and, with some practice and a few moments of blind panic, the first loop can actually be completed with relative ease as I accidentally did whilst recording the video.

I’ve got a fair bit of love for Chronos, in part because of the aforementioned nostalgia but also because it’s a fun game which is solidly written and well presented, especially with that measly £1.99 price tag. There’s an Amstrad CPC version as well which is reasonable but suffers from “Spectrum port syndrome”, having a slower refresh speed overall and omitting the Tim Follin goodness – the only sound is in-game effects which are basic AY zapping and exploding noises – so the Spectrum version as the one to play of the two.

Workprint – March 2018

So let’s get some workprint business out of the way first; since there are now two people showing an interest in converting Vallation to other platforms I might just have to properly shuffle it to the front burner and get on with building the new levels so they actually have a full game to convert. This process will doubtless involve lots of expletives – all aimed at myself for taking shortcuts or bodging – and possibly some rewriting or at least refactoring of the code because it seems to take far more processing time than I remember.

The RLE-based background compression I was mumbling about in the last update is also implemented and works surprisingly well, in fact there’s a simple but functionally complete game wrapped around it now. It has over 56K of background data in there which has been compressed into a mere 23.1K and takes around six minutes to scroll through at one pixel a frame. My intention is to get the entire game done rather than doing a “development diary” so I know it’s finished when writing the C64CD blog posts.

I’ve done a few more tests as regards grabbing video footage, again using VICE and OBS to this time accidentally record a full ten level playthrough of Warhawk. The results look quite solid, but there’s a bit more fiddling with settings I want to do and I have Vegas Pro courtesy of the Humble Bundle to install and get my head around… so who knows, perhaps I’ll become a rich and famous YouTuber? Well okay, probably just a YouTuber but I’m only doing it for the groupies anyway.

In other news, whilst I was away in Kent I met up with fellow Cosine inmates Darren Nevell , Frank Gasking and Sean Connolly for the twice-yearly internal meeting; that makes things sound all official and stuff, but we basically take up a corner of Starbucks and natter for the best part of a day. After nursing a coffee each for a couple of hours we then piled into Level Up and spent a happy hour or so trying to persuade ourselves not to buy everything in sight! Amongst other things I ended up with a PSU for one of my spare Atari 800XLs, a collection of books which are destined for the racking going into my office once it’s decorated including one about BASIC for the Dragon 32, an unboxed freebie of A64 – a C64 emulator for the Amiga which has a dongle for connecting peripherals – and… well, this thing:

Despite looking like an adolescent Enigma machine it’s actually a joystick interface for the Spectrum where each direction and the fire buttons can be connected to keys so pushing left on the stick is, as far as the computer is concerned, someone holding down the O key. I absolutely adore the bizarre but functional nature of this thing; it’s such a perverse work-around for the problem but at the same time will literally work on anything that doesn’t require actual typing to play. Come to think of it, you could also “type” rude words with the joystick…

Workprint – July 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…