11-05-08: All components have been soldered onto the PCB and after re-making the sound and blitter subsystems (due to timing issues) and adding the mouse interface logic it all appears to be working - huzzah!

What I will do now I think is tidy up the port / bit assignments - it'll make the V5Z80P temporarilly incompatible with my V4 laptop (and all the programs I've written for it) but I can update it and reassemble everything later.

06-04-08: Well I bit the bullet and got some PCBs for the V5 Z80 Project professionally made.. I sent the Gerber output files of Freepcb to a company called www.pcbcart.com and they did the business - the boards are lovely :)

I've made a start soldering on the components and converting the V4Z80P logic to the new design but other things have being hogging my time recently so I havent made as much progress as I would have liked. ATM, only the basics have tested, and the 16MHz Z80 is happily counting in binary on some LEDs whilst the TV displays a simple test card. Woo!

13-02-08: Still plodding along with my Bounder remake.. the title-screen and all the little routines that glue it all together are now in place. No real playable levels yet, though - just some test maps.

I took a slight detour to tinker with the sprite architecture in my video board - three improvements have been made: Firstly the sprite control registers can now be double buffered meaning it doesn't matter where you update the sprites during a frame - there wont be any glitches. Secondly, the sprite system now skips sprite image read/write cycles when a sprite is not present on a particular line, this way there is time for up to 127 sprite registers to be scanned per line. Although there's only time for 56 sprites to be drawn, most of the time there wont be 56 sprites on any given line so image data from the higher registers will be used - basically its "free" hardware sprite multiplexing. The final improvement was to make sprite definition RAM writable at any time, not just when sprites are disabled - like the background video, it now just holds the CPU wait line active if there is any access contention.

Also, prompted by interest in the site, I've been looking into the possibility of making a standalone Z80 V4 Project PCB. The board will have to professionally produced as it is way too time consuming to make it as I did originally (single-sided, wire-links etc.) It needs to be drawn up from scratch too as the original had extensive manual [ahem] "tuning" :) [Update] Have finished a draft board layout and it seems I would have to charge.. well see this page.

'Bounder 2008' - Coming soon to a Z80 Project near you.

08-01-08: I wanted the opportunity to give my V4 graphics system a good test, so I've been writing a game: a remake of the C64 classic 'Bounder'. Considering how few people are likely to play this I probably could've/should've chosen something more straightforward like the first wave arcade games or Ulitmate's 16K Spectrum titles but I figured Bounder had been kinda neglected on the remake front so I did that. It isn't a carbon copy - I'll be doing my own maps etc - but I've included most of the elements from the original game (and little from its not-so-good sequel:)

I haven't been going at it full tilt by any means but its coming along quite well. The core of the game engine is in place and I'm now adding the different enemy types - there's springs, teleports, fans etc as well as the more standard enemies to do. Stay tuned!