Search found 1315 matches

by srowe
Thu Mar 14, 2024 8:40 am
Forum: General Topics
Topic: modded VIC 20 kernals?
Replies: 12
Views: 396

Re: modded VIC 20 kernals?

Overdoc wrote: Thu Mar 14, 2024 7:18 am Another idea that just came to my mind would be a modified kernal, which makes the VIC20 compatible with a 1541 drive?
There's no compatibility problem between the VIC-20 and a 1541. The UI+/- allows you to recover the transfer speed loss that had to be added for compatibility with the C64.
by srowe
Thu Mar 14, 2024 3:42 am
Forum: General Topics
Topic: modded VIC 20 kernals?
Replies: 12
Views: 396

Re: modded VIC 20 kernals?

Without adding some form of bank-switching you would have to remove some functionality (as JiffyDOS does). That then prevents you from switching it while the computer is running. There's too much code that presumes it can use any part of the KERNAL, not just the public entrypoints, having any altern...
by srowe
Sun Mar 03, 2024 10:20 am
Forum: Emulation and Cross Development
Topic: VIC listing program
Replies: 5
Views: 222

Re: VIC listing program

Hello all, Though I've quite literally just joined Denial -- I only found it today -- I've been a VIC user on and off for all of my life. (Quick intro: my parents bought me one, brand new, back in 1981 or thereabouts, when I was... ahem... younger than I am now.) Well, here I am. And I wanted to be...
by srowe
Sun Mar 03, 2024 6:57 am
Forum: Programming
Topic: Screen Management
Replies: 3
Views: 284

Re: Screen Management

Starting from the decimal address 7680 (initial part of the screen), and having 22 columns x 23 rows, I would have a total of 506 bytes to write. Now if for example I used: LDX [screenData] STA $1E00,X and I made a cycle, the value of X could not be higher than the fateful 255, so how can I write t...
by srowe
Thu Feb 22, 2024 2:30 am
Forum: Games
Topic: German Magazine - Type-Ins - Compute Mit
Replies: 133
Views: 33358

Re: German Magazine - Type-Ins - Compute Mit

Richard has this magazine series in his Listings Archive

http://www.vic20listings.freeolamail.co ... mpmit.html

But there are a couple of programs not there (GRAPHOLOGIE and SUPER-RALLYE?). Perhaps you could send them to him to include?
by srowe
Wed Feb 21, 2024 12:50 pm
Forum: Emulation and Cross Development
Topic: Emulation of RS232 VIC20 for running multiplayer games
Replies: 34
Views: 10830

Re: Emulation of RS232 VIC20 for running multiplayer games

Why are pins B and C jumpered? Is it so that an interrupt is raised when data is received along PB0? I haven't looked at mimmosic's code yet, but I'm guessing that CB2 will be set to HANDSHAKE OUTPUT MODE for this to work? Correct, the receive line must be connected to both CB1 and PB0 so that a in...
by srowe
Sun Feb 18, 2024 3:34 am
Forum: Programming
Topic: "Free ZP" which ones?
Replies: 6
Views: 241

Re: "Free ZP" which ones?

coming from Atari 800 and C64 I am used to switch off OS completly and having the ZP "free". on the VIC20 I can not do this but using the IRQs mainly so just to be sure. what are the ZPs which are really free? :) There are very few locations that are completely unused $2A $52 $FB - $FE Th...
by srowe
Mon Feb 12, 2024 12:52 pm
Forum: Collecting and History
Topic: How to convert Tap files to D64?
Replies: 11
Views: 294

Re: How to convert Tap files to D64?

Standard (i.e. without a fastloader) .tap files can be converted to d64 using my command line tool

https://cbmshell.readthedocs.io/en/latest/index.html

As Mike points out, if the code tries to chain load another program, read data files etc that needs to be fixed up manually.
by srowe
Mon Feb 12, 2024 1:49 am
Forum: Collecting and History
Topic: 5 Ultra-Rare Games by "Aim Software"
Replies: 7
Views: 307

Re: 5 Ultra-Rare Games by "Aim Software"

A couple years ago I posted several ALA Software games and a member was able to generate the entire list in a D64 file. That would be awesome if somebody again could lump them all in one D64 file. I think this is the thread you mean https://www.sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php...
by srowe
Sun Feb 11, 2024 8:27 am
Forum: Emulation and Cross Development
Topic: Corrupt end of basic program
Replies: 7
Views: 259

Re: Corrupt end of basic program

Have you got a short BASIC loader program that then chains a longer BASIC program? This combination causes the end of the second program to be overwritten by variables, in this case the start of variables (VARTAB) is not updated.
by srowe
Fri Feb 09, 2024 12:23 pm
Forum: Programming
Topic: "Ultimate Expansion" - new firmware for FE3
Replies: 58
Views: 9563

Re: "Ultimate Expansion" - new firmware for FE3

The IRQ clock, i mean could be placed under the normal screen. And of course with an alarm set and alarm tone. Taking over the IRQ once you've left the FE3 menus would be tricky. If you enter BASIC it would work ok until you wanted to run a program. It certainly wouldn't behave well if you launch a...
by srowe
Sat Feb 03, 2024 8:43 am
Forum: Emulation and Cross Development
Topic: Keyboard Buffer and Ctrl/Shift/CBM etc
Replies: 20
Views: 869

Re: Keyboard Buffer and Ctrl/Shift/CBM etc

SparkyNZ wrote: Sat Feb 03, 2024 8:12 am Right, so this is the result of the CRNCH routine?

Code: Select all

89 20 31 30 00
Correct.
Probably pay me to step through that routine and dump that piece of memory as it goes
Using the monitor in VICE is a good way of understanding how this all works.
by srowe
Sat Feb 03, 2024 1:58 am
Forum: Emulation and Cross Development
Topic: Keyboard Buffer and Ctrl/Shift/CBM etc
Replies: 20
Views: 869

Re: Keyboard Buffer and Ctrl/Shift/CBM etc

Is the BASIC Input Buffer already tokenised? It is tokenized by the BASIC main routine that processes program input MAIN JMP (IMAIN) ; do BASIC warm start ;***********************************************************************************; ; ; BASIC warm start, the warm start vector is initialised...
by srowe
Thu Feb 01, 2024 1:46 am
Forum: Programming
Topic: "Ultimate Expansion" - new firmware for FE3
Replies: 58
Views: 9563

Re: "Ultimate Expansion" - new firmware for FE3

I miss two thinks on the FE3. - a clock like Mikes IRQ clock - some old fashion screen saver Do you mean these to be available while in the FE3 menus (rather than the BASIC wedge)? For the clock I'll have a think if that would fit on a subset of menus but screen space is tight so that wouldn't real...
by srowe
Sun Jan 28, 2024 2:31 pm
Forum: Programming
Topic: Recommendations for VIC-20 assembly tutorial, tools
Replies: 10
Views: 647

Re: Recommendations for VIC-20 assembly tutorial, tools

I'm new to assembly language, and I would like to learn it for the VIC-20. There's a range of books that could be of help, which one(s) that will work for you depends on your background, how much knowledge you already have of the hardware, etc. https://commodore.bombjack.org/generic/generic-books-p...