Search found 550 matches

by groepaz
Mon Dec 11, 2017 6:29 am
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

yeah right at startup (it doesnt quite start that is :))
by groepaz
Sun Dec 10, 2017 5:58 pm
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

Are you sure? I've got my emulator working now. At the start of the game, it appears to set the following: oh! interesting :) i must have somehow missed that in the process... i had to add some of my own init stuff to make it not show crap at least :) your emu crashes on me though :( $ java -jar at...
by groepaz
Sun Dec 10, 2017 6:38 am
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

I don't think the control registers themselves have intended default values on startup of the chip.

at least some of them must have defined default values - else this game would show random garbage :)
by groepaz
Sat Dec 09, 2017 6:53 pm
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

the game does very few actual accesses to the VIC, so its almost useless to tell the differences by looking at the game code... one thing that is obvious though is that the defaults differ :) meanwhile, i have it kinda working without a patched kernal.... the monkey patched screen copying stuff make...
by groepaz
Sat Dec 09, 2017 8:03 am
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

making a custom emulator will be fairly straightforward if you already have a a vic20 emulator... the differences are small, besides the memory mapping (already discussed here) you'll have to mask the whole memory access by $3fff (so the hardware vectors are at $3ffx, not $fffx) and perhaps tweak th...
by groepaz
Fri Dec 08, 2017 5:57 pm
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

I'm not sure what you mean by this. Can you elaborate? yes: brainfart :) the game must be using 1c00-23ff for characters. with the actual letters and symbols in the 2000-23ff area, 1c00-1fff is used for the invader "sprites" etc i got slightly further with running it without a patched ker...
by groepaz
Thu Dec 07, 2017 1:40 pm
Forum: Hardware and Tech
Topic: HASL for cartridges? (split/OT from: Cheese & Onion)
Replies: 123
Views: 1426

Re: HASL for cartridges? (split/OT from: Cheese & Onion)

i hate you. i ran out of popcorn :(
by groepaz
Wed Dec 06, 2017 4:51 pm
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

yep, and 1c00-1fff is used for dynamic characters, 2000-23ff contains static characters. the hardware also seems to be wired up in a way that upper and lower half of the character set are swapped (compared to what we know from vic20)
by groepaz
Wed Dec 06, 2017 2:33 pm
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

so far what i have done is hooking into a routine that gets called once per frame, and then i just copy the screen (and color ram) to some location that is suitable for vic20 :) changing the addresses in the program is certainly possible too... but as said, a lot of work, since its not really obviou...
by groepaz
Wed Dec 06, 2017 7:29 am
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

rotating everything would basically mean rewriting the game, i am certainly not attempting this :) actually, even making it work on actual vic20 without the terrible hacks i have been using (eg i modified kernal) seems difficult without putting a lot of effort into it but yes, controls work, it can ...
by groepaz
Tue Dec 05, 2017 4:19 pm
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

i was interpreting some things wrong :) this game uses some really unusual programming techniques (which unfortunately will make it quite some work to patch :/) i have it "running" now ... in the sense that i can start the code, it runs and doesnt crash, and i can see the rendered screen i...
by groepaz
Tue Dec 05, 2017 12:41 pm
Forum: Other Systems
Topic: Attack UFO - Arcade game that uses the 6560
Replies: 43
Views: 591

Re: Attack UFO - Arcade game that uses the 6560

found it :)

is it for certain that it uses a 6502 and not 65C02 or other derivate? if its really 6502, then there is quite a bit of "illegal" opcode usage =P
by groepaz
Tue Dec 05, 2017 9:52 am
Forum: Hardware and Tech
Topic: HASL for cartridges? (split/OT from: Cheese & Onion)
Replies: 123
Views: 1426

Re: HASL for cartridges? (split/OT from: Cheese & Onion)

just let it go...

and share some of that popcorn will ya? 8)
by groepaz
Tue Dec 05, 2017 6:14 am
Forum: General Topics
Topic: GeoRAM on the Vic20
Replies: 5
Views: 180

Re: GeoRAM on the Vic20

I'm a bit dubious about the VICE implementation, since seems to be mapping three GeoRAM across both I/O slots. three? how three? *shrug* it maps the registers into the IO2 area (dffe/ff - with mirrors across the whole page due to incomplete decoding) and the actual RAM page into IO1 (dexx). nothing...

Go to advanced search