Christopher Tumber Posted June 4, 2023 Share Posted June 4, 2023 (I know 20 years - WTF?!?) ;Updates since original release: ; Slow down UFO ; Use UFO score table from arcade version ; Make UFO start position based on shot count ; Aliens drop one row lower ; Title screen with settings menu ; Implement Sound setting in game ; Implement NTSC/PAL colour settings in game ; 20th anniversary logo ;To Do ; Improve Shot Display (less flicker) (may not be possible) ; Optional Multicolour Instigators (Non-trivial - need to free ROM space or expand to another bank) ; Ensure smooth transition between Title Screen and Game Screen (no roll caused by too few or too many scanlines) ; Verify UFO scoring is correct (shot counting) ; Verify stable scanlines during game Note: Demo version, requires hard reset after each game. 10 1 Quote Link to comment Share on other sites More sharing options...
+sramirez2008 Posted June 4, 2023 Share Posted June 4, 2023 Looking good and looking forward to this update. @Christopher Tumberwill you be adding the demo bin to this thread? I don’t see it. Quote Link to comment Share on other sites More sharing options...
Christopher Tumber Posted June 4, 2023 Author Share Posted June 4, 2023 I did attach the .bin to the original post. Let's try again... Sp20th.bin 3 2 Quote Link to comment Share on other sites More sharing options...
+sramirez2008 Posted June 4, 2023 Share Posted June 4, 2023 I see it now. Thanks. Quote Link to comment Share on other sites More sharing options...
+sramirez2008 Posted June 4, 2023 Share Posted June 4, 2023 Had time for one game. Score is actually 12,860 (turned over at 10k). I did not encounter any screen rolls. I let the game play (2nd pic) and the UFO came out before I fired any shots. Quote Link to comment Share on other sites More sharing options...
TrekMD Posted June 4, 2023 Share Posted June 4, 2023 Very cool! Quote Link to comment Share on other sites More sharing options...
+cjherr Posted June 5, 2023 Share Posted June 5, 2023 Thank you! Quote Link to comment Share on other sites More sharing options...
Christopher Tumber Posted June 5, 2023 Author Share Posted June 5, 2023 23 hours ago, sramirez2008 said: I let the game play (2nd pic) and the UFO came out before I fired any shots. Hmm... Is it not supposed to? I just tried the arcade version on emulator and I got UFOs without ever firing a shot... I'm not sure where I copied this from anymore, but these are the notes I have as far as UFO behaviour from when I was fixing the UFO. Th one thing I now notice I haven't done is preventing the UFO from appearing before the first row descends. Which would be a really simple flag if I had either RAM or ROM space available Put it on the todo list since I need to find ROM space anyway and I probably have an available bitflag somewhere. (I don't remember how I determine when the UFO shows up may or may not be every 20 seconds) ;To the UFO show in arcade, the invaders need to be below the first row in the first wave. I mean, in the first wave, the program will wait for the invaders go down a ;row before starting computing the UFO. For the next waves, they already start below this row. ;After that, the UFO will show every 600 frames, supposing you have a 30 frames per second frame rate (it leads to 20 seconds)… ; ;About the correct UFO velocity, enough to say the arcade moves just a game object per frame, beside the invaders themselves. So you have your base, base shot, 3 invaders ;shots and the UFO… The UFO increment is 2 pixels every move and the side it will show (right or left) will be randomly decided. ; ;Here is the ordered UFO score table. It is a circular list, and the pointer moves every shot you fire. ; ;100,050,050,100,150,100,100,050,300,100,100,100,050,150,100,050 ; ; ;The flying saucer’s direction is linked to the player’s shot count. The lowest bit of the count determines which side of the screen the saucer comes from. ;If the saucer appears after an even number of player shots then it comes from the right. After an odd number it comes from the left. ;The saucer object structure is re-initialized every time the player’s shot blows up. Here is the code in Object 1 (player fire): 1 Quote Link to comment Share on other sites More sharing options...
Bomberman94 Posted June 6, 2023 Share Posted June 6, 2023 Thank you for this game - played it on a PAL Atari 2600 and CRT. Everything’s fine except a short screen jump after game over/end of the game. Quote Link to comment Share on other sites More sharing options...
dancero Posted June 7, 2023 Share Posted June 7, 2023 is it possible to add a sound when the ufo is destroyed? Quote Link to comment Share on other sites More sharing options...
+ZeroPage Homebrew Posted June 15, 2023 Share Posted June 15, 2023 ZeroPage Homebrew is playing Space Instigators 20th Anniversary Edition on tomorrow's ZPH stream LIVE on Twitch, hope you can join us! Fri Jun 16, 2023 | LIVE @ 12PM PT | 3PM ET | 7PM GMT WATCH LIVE: https://www.twitch.tv/zeropagehomebrew/WATCH LATER: https://youtube.com/zeropagehomebrew/ Games: Meooow (2023 Exclusive World Premiere | 2600) by Mirsad Sarajlic @kikipdph Space Instigators 20th Anniversary Edition (2023 WIP | 2600) by Christopher Tumber @Christopher Tumber Roll Play (2023 WIP | 2600) by Glenn Main @Glenn Main WATCH AT 1080P60 FOR BEST QUALITY 2 Quote Link to comment Share on other sites More sharing options...
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