Search found 550 matches

by nippur72
Fri Dec 15, 2023 5:09 am
Forum: Programming
Topic: Increasing the number of sound voices?
Replies: 4
Views: 2730

Increasing the number of sound voices?

When playing tracked music there's this effect called "arpeggio" where a chord is simulated by playing the notes of the chord in very small time slices over a single sound channel. Now I was wondering if this technique could also be used to play not just chords but independent notes, so to...
by nippur72
Fri Sep 01, 2023 5:52 am
Forum: Games
Topic: The Hardhat Climber, 2023 turbo edition
Replies: 1
Views: 1988

The Hardhat Climber, 2023 turbo edition

Hi, I've taken the liberty of creating a slightly enhanced version of "The Hardhat Climber", the iconic type-in BASIC game by Chris Lesher. After reverse engineering it, I turned it into machine language using the Mospeed compiler, making it a little faster than the original and also imple...
by nippur72
Sun Aug 20, 2023 11:56 am
Forum: Emulation and Cross Development
Topic: VICE Noise
Replies: 2
Views: 2078

Re: VICE Noise

I'm a bit late to this post, but yes it's the enabled equal to zero that causes the first bit shifted in the LFSR. Note that once the LFSR<>0 it never gets 0 again but loops over the 65535 values (65536 less one). Check out the following threads from where the current implementation in VICE comes fr...
by nippur72
Fri May 19, 2023 12:44 am
Forum: Emulation and Cross Development
Topic: Another C cross compiler with C99 support
Replies: 3
Views: 2063

Re: Another C cross compiler with C99 support

look cool, must give it a try!

My compiler of choice for 6502 currently is KickC, but I'm curious to compare the two.
by nippur72
Sun May 15, 2022 1:45 am
Forum: General Topics
Topic: Albert Charpentier talks about VIC20 and VIC-I on Dave's Garage
Replies: 2
Views: 466

Albert Charpentier talks about VIC20 and VIC-I on Dave's Garage

Albert Charpentier talks about the VIC-I chip and the VIC-20 on Dave's Garage !

https://www.youtube.com/watch?v=rs6J_PP7O7k
by nippur72
Sat Feb 19, 2022 4:06 am
Forum: Programming
Topic: A good book or written piece about large resolutions on VIC?
Replies: 8
Views: 1162

Re: A good book or written piece about large resolutions on VIC?

this thread has a picture of the max screen size tested on my old CRT TV
by nippur72
Sat Apr 24, 2021 4:28 am
Forum: General Topics
Topic: Problems with Dawson's web emulator
Replies: 8
Views: 688

Re: Problems with Dawson's web emulator

yes you can load an external .prg file with something like this:

https://nippur72.github.io/vic20-emu/?j ... myprog.prg

(joy=1 is used to turn joystick emulation with cursor keys, you can omit it)
by nippur72
Tue Apr 20, 2021 4:04 am
Forum: Emulation and Cross Development
Topic: vic20-emu (another emulator)
Replies: 43
Views: 2995

Re: vic20-emu (another emulator)

The emulator now supports USB gamepads :D
by nippur72
Mon Apr 19, 2021 3:53 pm
Forum: General Topics
Topic: Problems with Dawson's web emulator
Replies: 8
Views: 688

Re: Problems with Dawson's web emulator

alex.kirk wrote: Tue Apr 06, 2021 4:34 pm Then I would need to run the Javascript on another website, is that possible? How to do? Is there another similar emulator?
Have you already tried https://nippur72.github.io/vic20-emu ? It has zero user interface but the emulation is quite accurate (tough not comparable to VICE).
by nippur72
Sun Apr 18, 2021 1:51 pm
Forum: Hardware and Tech
Topic: Commodore cartdriges anti-screen flutter key?
Replies: 7
Views: 550

Re: Commodore cartdriges anti-screen flutter key?

tokra wrote: Sun Apr 18, 2021 1:03 pm No, sorry, none of the 4 files in the ZIP can control the image vertically, just horizontally as the Zimmers-one.
no this is the only one I have. BTW is there a theory why Commodore cartridges did worry to allow screen alignment? Why not just use the register values in the ROM kernal?
by nippur72
Sun Apr 18, 2021 10:37 am
Forum: Hardware and Tech
Topic: Commodore cartdriges anti-screen flutter key?
Replies: 7
Views: 550

Re: Commodore cartdriges anti-screen flutter key?

I have this file for the cartdr... cardtr... cartridge :D which has the cursors keys thing: Jupiter Lander.zip I apprehended only recently about the interlaced vs non-interlaced mode, I realized it's the actual reason why we are able to see the scanlines, it's because we are only seeing odd frames, ...
by nippur72
Sun Apr 18, 2021 3:33 am
Forum: Hardware and Tech
Topic: Commodore cartdriges anti-screen flutter key?
Replies: 7
Views: 550

Commodore cartdriges anti-screen flutter key?

In Jupiter Lander cartdrige manual, there is a small note: Eliminating Screen Flutter On some TV sets with automatic fine tuning your screen may "flutter" up and down when using a computer or video game. To correct this, hold down the [SHIFT] key and hit the [F7] key. (NOTE: Doing this wit...
by nippur72
Fri Feb 12, 2021 1:07 pm
Forum: Emulation and Cross Development
Topic: Tape format document
Replies: 6
Views: 850

Re: Tape format document

Great document, thanks! I've always wondered why the CBM format was so redundant compared to other formats or even turbo tape. Now I have all the answers! Also very interesting the .TAP section, I recently wrote a tap<=>wav utility that I now need to match with this new information.
by nippur72
Sun Jan 17, 2021 12:26 pm
Forum: Programming
Topic: vertical scrolling
Replies: 3
Views: 456

Re: vertical scrolling

I think you can get a faster scroll-copy routine if you work in blocks rather than lines, e.g. 2 blocks of 253 bytes ldx #253 loop: lda 7680-1+22*1,x sta 7680-1+22*0,x lda 7680-1+253+22*1,x sta 7680-1+253+22*0,x dex bne loop (I haven't checked it, the actual numbers need to be verified)
by nippur72
Wed Jan 13, 2021 2:54 pm
Forum: Programming
Topic: Tapadjust: Vic-20 head alignment
Replies: 10
Views: 1021

Re: Tapadjust: Vic-20 head alignment

very nice tool. I have a related issue, that is finding the right level when you playback WAV files from the PC to the real VIC (I do that via a car-cassette adapter). I find the volume level is rather critical. I was about to write a tool of my own for that purpose. My idea was to create an audio s...