Somebody on itch.io reported that SkillGrid hangs on his/her A4000 (with 68060), but provided no details. Luckily, one of my friends/testers has an A4000 equipped with a 68060 and managed to reproduce the problem (if not exactly the same, I hope a strictly related one).
What he found out is that if he had Roadshow running, the game would hang in the title screen shortly after starting up. Given that SkillGrid takes over the system entirely, the first thing that came to mind was that his network board (an X-Surf-100), after being activated/used by RoadShow before the startup of the game, was triggering an INT2 interrupt and keeping on doing so continuously as it was not getting an ack due to the fact that my level 2 interrupt handler, which only cares about the keyboard, simply cleared the INTREQ.PORTS bit and returned. I searched for information about the X-Surf-100 on the net and I got confirmation that it uses the INT2 line (and seemingly also the INT6 one, but that is not relevant to SkillGrid as it has the level 6 interrupt disabled). I provided him with a version of the game with the level 2 interrupt disabled and it turned out to work just fine, even with RoadShow running at startup.
Therefore,
I have now prepared a new version (1.3) which handles the keyboard through the level 3 interrupt and which is thus immune to any expansion hardware (except for hardware that continuously triggers NMIs, that is).
Doing this work got me started once again, and so
I also made some other improvements - you can find the details in the changelog at the bottom of this post, but here's the most important one:
For who is not familiar with the game: the addition is the BEAM/ULTRA cell, which makes the spaceship weapon exceptionally powerful (getting rid of the bosses with it is extra easy).
I seized the occasion to also add this little paragraph to the manual which clarifies how beams work (it has been so since day 1, but it had never been explained):
The new version is practically ready, but before releasing it
I'd really really really like to get the Amiga CD32 NVRAM issue fixed! In fact, hiscore loading/saving is still disabled for the version that boots on Amiga CD32 directly from CD. Unfortunately, having no such machine, I can't test my code, so I need help. More precisely, I need someone with an Amiga CD32 equipped with an HD/CF/SD to run
this test suite and report the result (it's all very simple - basically: download the archive, unpack it on the drive, run the script from shell, follow the on-screen instructions and report the result).
Thanks in advance to the good souls who will help!
Changelogv1.3 (unreleased)
1. Added the BEAM/ULTRA cell (shoots a big beam that is equivalent to 5 beams).
2. Moved lateral beams of the triple beam one pixel down (to match the shape of the ultra beam).
3. Reduced by 16.7% the occurrences of the DAMAGE cell.
4. Worked on the music playback: optimized the decoding; optimized the handling of the state; removed the pairing of channels on the same side (which caused the title and game over screens music to play louder than the in-game music - an originally intended effect which I have changed my mind about - and did not really work for channel 3 as that channel cannot sustain 28836.5 Hz).
5. Changed the keyboard handling so that it executes from a level 3 interrupt handler instead of a level 2 interrupt handler, in order to work around issues/lockups caused by expansion hardware sending INT2 interrupt requests.
6. Replaced [SPACE] with [LEFT ALT] and [RIGHT ALT] keys as [FIRE] button.
7. Made the startup procedure more robust (especially against audio playback performed with direct hardware access by other programs concurrently).
8. Made various little optimizations.
9. Worked on cells graphics: fixed colors of beams on BEAM/DOUBLE and BEAM/TRIPLE cells; fixed a pixel on the border of the ASTEROIDS, BEAM/DOUBLE and BEAM/TRIPLE cells.
10. Worked on manual and stragegy guide: renamed DOUBLE BEAM and TRIPLE BEAM as BEAMS/DOUBLE and BEAMS/TRIPLE, respectively; added the information for the BEAMS/ULTRA cell; adapted the information for the other BEAMS/* cells; added the BEAMS paragraph; updated the ASTEROIDS, BEAM/DOUBLE and BEAM/TRIPLE cells images; updated the controls table; fixed the outer antialiasing of the BEAM/TRIPLE, BOOST and BRAKE cells images; fixed the kerning of the last character of the italic strings.
11. Set default tool of manual and strategy guide icons to "Apdf".
12. Updated artwork to reflect the new beams graphics.