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Dear Zephyr,
Added references here:
http://www3.ns.sympatico.ca/jimgerrie/jsoft.html
http://www3.ns.sympatico.ca/jimgerrie/jgames.html

jgerrie wrote:Dear Zephyr,
Added references here:
http://www3.ns.sympatico.ca/jimgerrie/jsoft.html
http://www3.ns.sympatico.ca/jimgerrie/jgames.html

Thanks, Jim. I'm happy with that.

zephyr wrote:I just remembered that reading the keyboard by peeking the keyboard rollover table won't work properly on CoCo 2's without adding extra lines to constantly call the INKEY$ function in the same loop.

I have discovered that using EXEC to call the keyboard routine directly is much faster than using A$=INKEY$. Another good thing about using this method is that (unlike A$=INKEY$) it doesn't stop PEEK(135) being used. The first step is to set up the EXEC vector outside of the loop with EXEC41419 ($A1CB is the real start address of the keyboard routine). Then simply use EXEC in the main loop to keep the rollover table updated as quickly as possible.

Example Jim, I now remember that you were the person who informed me that using A$=INKEY$ prevents the use of PEEK(135). Now we have a much better alternative for future use in all BASIC game code.

Regards,
Steve

I have updated my customised version of the game with the new code. Its noticeably quicker now when the game is running on a CoCo 2.

I have improved my inverse text routine. The routine is now faster at printing characters to the screen, and has a much faster screen scroll. It also has a new CHR$(12) feature (Inverse CLS) added for use in future games. Here are some test results using the previously mentioned QWERTY speed test under Dragon 64 (T3) emulation.

Dragon 64 = 11.32 Seconds
Dragon 64 + old routine = 10.38 Seconds
Dragon 64 + new routine = 8.36 Seconds

I have added the new routine both to my customised version, and to Jim's last release. I had to change the way that the keyboard is read in Jim's latest release to the more conventional method so that I could add CoCo 2 compatiblity.

Jim, I think you will be quite happy with the result. The improved performance of the new inverse text routine allows you to enjoy the game speed that you and your son like, along with added CoCo 2 keyboard support. After testing them both side-by-side it looks to me that it now compares favourably with the speed of your original MC-10 version without using the double speed poke.

Those changes are great. I noticed though that now my laser scores points when it hits meteors instead of just when you shoot the enemy ships. Is that a mod or something that slipped in during the mods? In any case amazing stuff, and I was able to test it out easily in coco2 and dragon mod under xroar having found your helpful setup/roms package elsewhere in the uploads. Thanks very much.

jgerrie wrote:Is that a mod or something that slipped in during the mods?

Its something that slipped in during the mods.