Fruitcake wrote: ↑Sat Jun 11, 2022 11:16 pmIt was quite well known for several years that there were two editions of the ZX81 ROM (referred to somewhat strangely as the 'unimproved' and 'improved' ROMs in various books and magazines), so why did Software Farm not check for compatibility with both ROMs before releasing the game?
I never really got to the bottom of that, it may be the mysterious (and unpublicised) THIRD ROM release that caused the issues,
viewtopic.php?f=7&t=4016
I just remember a routine accessed a rom address which had changed in this newer rom, it was a simple fix of course, but not much good once all the tapes were already produced and sent out.
So issues with a single game could take down an entire distribution company due to a title for the ZX81, a machine in the twilight of its commercial life, compared to all the Spectrum and C64 titles that dominated the computer games market at that time? Z-Xtricator must have been very, very popular...
The problem was their distribution network was ruined, Tiger Distribution had even got tapes into local newsagents, and according to The Software Farm they weren't able to sell tapes hardly anywhere after the 100s of returns - I'm remembering from ~40 years ago though, I didn't keep the letters, but they were pretty annoyed I can tell you that (even expressing their regret at publishing the game which "wasn't up to the standard of their previous games" (or something very similar)), but I didn't really question anything at age 15, I was glad for the ~£600 quid to be honest
How about something a bit sooner? It would be fascinating to see "bugs" and what might have been...
I lost all almost my old retro computers stuff (including tapes and painstaking pages of code design) over the years after moving away from my parents home, having a career (in IT) and raising a family. When the house was sold the only thing I could find was a ZX Spectrum which my brother had experimented on and pretty much ruined (lol)
But I didn't realise at the time that my pseudo hi-res routine had a huge benefit over the others on the market in that it didn't require a separate 6k 192 line display file. The Software Farm confused me at first when they said my routine used far less memory, and it was only recently that I have looked at the documentation on pseudo hi-res and saw that my method (driven by INT mode 2) was much more pseudo UDG (characters) than pseudo hi-res. The disadvantage was that I couldn't move characters smoothly by 1 pixel up and down, but it enabled pretty good pseudo-UDGs with the full standard font also available (see screenshot of Z-XTRICATOR for example
https://www.mobygames.com/game/zx81/z-x ... Id,681834/ ) and perfect diagonal lines at certain angles.
The routine is listed at the bottom of the article here
https://8bit-museum.de/heimcomputer-2/s ... ay-system/ (I remember wondering if the small number of dummy instructions used for delays to get the timing perfect could be used to do something more useful)
In fact games like Z-Xtricator could load in just a couple of minutes but The Software Farm insisted I added their usual "huge" 6k loading screen which I was pretty puzzled by at the time, it seemed unnecessary to add several minutes to the loading time for this (in fact that loading screen is displayed using their old hi-res routine, and then Z-Xtricator switches to the pseudo-UDG method once the game starts)
I wish I still had the code for "BUGS" it looked even more impressive with perfect looking UDGs and much better gameplay.
EDIT: I found an online video of Z-Xtricator being played in its full glory
https://www.youtube.com/watch?v=0m0aMA2CpUE (although the user seems to have given up on trying to save humanity after a few cowardly attempts, shocking really)
fun fact: when the ship goes down towards the surface of the planet to rescue the human, "DANGER" appears and the ship starts "shaking", this was due to the fact I couldn't work out how to stabilise the ship and scroll the landscape simultaneously (the whole area of memory in the display file is shifted including the THREE characters for the spaceship), so I invented this bullshit about the strong gravity near the surface causing the ship to shake. It actually wasn't such a bad effect really, even if unintentional...
