Search found 16 matches

by andym00
Sun Feb 03, 2013 6:36 am
Forum: Buy, Sell, and Trade
Topic: *SOLD OUT* 32k RAM expansions for the VIC-20 - 25$ each
Replies: 60
Views: 12181

Fingers crossed :) I've always been a bit of a purist in my love of the VIC in it's unexpanded state, but lately I've been playing with and massively enjoying the expanded VIC and its potential there.. Problem is I've no 24K or 32K RAM expansion to test with on the real thing :)
by andym00
Wed Jan 30, 2013 12:08 pm
Forum: Buy, Sell, and Trade
Topic: *SOLD OUT* 32k RAM expansions for the VIC-20 - 25$ each
Replies: 60
Views: 12181

I'd so love one of these if there's any still available ?
Probably not a snowballs chance in hell I guess, but what have a I got to lose by asking ? :)
by andym00
Wed Jan 30, 2013 12:04 pm
Forum: Programming
Topic: Smooth vertical scrolling problem...
Replies: 4
Views: 3704

I stumbled across it just by playing with a program to test screen sizes, allowing me to control width, height, x position, y position.. I simply noticed that when HPOS was 0 the screen moved by one single raster line from the set VPOS value of 2 line resolution, and a spark ignited :) I haven't fou...
by andym00
Sun Jan 27, 2013 4:32 am
Forum: Programming
Topic: Smooth vertical scrolling problem...
Replies: 4
Views: 3704

Smooth vertical scrolling problem...

I'm trying to setup a vertical scrolling screen, but smoothly using HPOS==0 to delay the screen by the extra line to get single line position.. This works fine, and very well.. On top of that, I also want to blank the top of the display to hide the offscreen region so it scroll on smoothly without h...
by andym00
Sat Aug 25, 2012 1:58 pm
Forum: General Topics
Topic: USB download options ?
Replies: 5
Views: 1045

It looks shit IMHO :)
Nothing like the real thing, but let's not distract from what I'm asking ;)
by andym00
Sat Aug 25, 2012 12:08 pm
Forum: General Topics
Topic: USB download options ?
Replies: 5
Views: 1045

I know, but my monitor is still stuck at a fixed 60hz.. And emulating a 50hz machine.. I find the effect massively disconcerting..
It's the only time I wish I developed for NTSC land;)
by andym00
Sat Aug 25, 2012 10:43 am
Forum: General Topics
Topic: USB download options ?
Replies: 5
Views: 1045

USB download options ?

Whilst busy canning my retro bug I discovered I couldn't come to be parted from my VIC's, which inspired going back to basics and re-discovering why the VIC made me fall in love with it, from a programming point of view and game-play point of view also.. That aside.. Are there any options on the mar...
by andym00
Thu Mar 15, 2012 2:33 am
Forum: Programming
Topic: Pulse Sounds..
Replies: 8
Views: 2316

Erm, it's not clear is it, but I didn't have the memory for a fancy CPU load like the 64 version.. The multicoloured bit is just a fixed loop (of ~10000 cycles) run from a per frame interrupt.. It's there to show how much variance there is from the interrupts running in the background, hence why it ...
by andym00
Wed Mar 14, 2012 11:07 am
Forum: Programming
Topic: Pulse Sounds..
Replies: 8
Views: 2316

Well the whole thing was initially just an idea of a way to synthesis some additional voices without the normal massive cpu-overhead required.. To test it out, rather than writing a full blown music driver in parallel, I simply grabbed so NES NSF music files, and then wrote a later to convert the 3 ...
by andym00
Tue Mar 13, 2012 4:27 am
Forum: Programming
Topic: Pulse Sounds..
Replies: 8
Views: 2316

Pulse Sounds..

Well, actually more about synthesising lots of software voices, but with little CPU overhead, well much less than traditional means, and the bonus is the voices are playing back at 15.6K.. Really :) It's an idea from a long time ago, and after a few silly ideas ideas ended up with something useful.....
by andym00
Tue Jan 17, 2012 7:32 am
Forum: Programming
Topic: Sid Vicious - VIC 20 SID emulation
Replies: 65
Views: 35778

This may be of interest: vice-emu/testprogs/general/ane-lax/ IIRC lax #$00 is indeed stable on the machines we tested. Oh, now that is a lovely analysis of the whole ANE & LAX situation.. I had no idea that that page existed before.. Thanks for all the hard work you must have put into that anal...
by andym00
Mon Jan 16, 2012 7:55 am
Forum: Programming
Topic: Sid Vicious - VIC 20 SID emulation
Replies: 65
Views: 35778

just noticed you're talking about the specific LAX #immediate addressing mode - this IS flakey on most 6502s and generally not included in lists of LAX addressing mode documentation. So the question flips around - what's the board and CPU of the 128 where it DOES work? ;) I've no idea :) It's merel...
by andym00
Sun Jan 15, 2012 5:36 am
Forum: Programming
Topic: Sid Vicious - VIC 20 SID emulation
Replies: 65
Views: 35778

Um, look at that: ;----- table of selfmod locations selfmodloc: .byte o1add_,o1addh_,o1wav_,o1pw_,o1ple_,o1phe_,o1lev_ .byte o2add_,o2addh_,o2wav_,o2pw_,o2ple_,o2phe_,o2lev_ .byte o3add_,o3addh_,o3wav_,o3pw_,o3ple_,o3phe_,o3lev_ So unless you are prepared to change the way ALL of these switches wor...
by andym00
Sun Jan 15, 2012 4:32 am
Forum: Programming
Topic: Sid Vicious - VIC 20 SID emulation
Replies: 65
Views: 35778

It's rather massively self modifying really, but I think there's enough cycles to be saved that you could pull it out of the ZP without losing any speed with enough thinking.. Just looking quickly, looks like you can save 3 bytes on the ;- oscillator switch o1wav_: jmp o1off since this is always pre...
by andym00
Fri Jan 13, 2012 8:58 am
Forum: Programming
Topic: Sid Vicious - VIC 20 SID emulation
Replies: 65
Views: 35778

Unfortunately, the original source code apparently disappeared from the net. I will release a version with "Vicious SID Converter" quite soon. I got that impression when I went looking for it about a year ago or so.. Couldn't find it anywhere on the internet at all.. Was half tempted to m...