Denial

Are the "and" and "or" operators short-circuited in basic v2? No, they aren't. Expressions are always evaluated in full. Furthermore, AND, OR and NOT operate on signed 16-bit quantities. The result of a relational operator ('=', '<', '>' or any combination thereof) is -1 if the ...

So any input on this front is most welcome. If you want to keep it somewhat restrained, you should consider a +16K RAM expansion as 'soft' limit. At the time, this was the biggest single RAM expansion cart sold by Commodore (the VIC-1111). Anything bigger than that would have required either a cart...

The screen editor of the VIC-20 accepts up to four physical lines as a single logical line, i.e. 88 characters. With abbreviations (for example, ? for PRINT, F SHIFT-O for FOR, N SHIFT-E for NEXT, etc., see the VIC User's manual), you can enter some more code into these four lines. When this line is...

[...] a little (perl?) script that creates basic lines from the coordinates. My problem is how to write the petscii chars and rvson/rvsoff, so that they paste correctly into vice or basedit. As I wrote elsewhere , the copy&paste facility of VICE is just unusable beyond simple text I/O. Again, w...

Why this intermediate step with a list of pixel co-ordinates?

You can convert the B/W image directly to a BASIC program which consists solely of PRINT statements (and two POKEs into screen and colour RAM for the bottom-right character), which is much more efficient speed- and memory-wise.

Hmm? I was under the impression, that NTSC had a different pixel aspect ratio more like 1.5:1 (which would correspond to 0.750 in VICE). :? I got my value a long time ago by measuring the width and height of the text window of the VIC-20 on a TV set, which had been confirmed before to draw perfect c...

This 2:1 ratio (i.e. simple pixel doubling) was what VICE always used for display until around version 2.1 when fractional pixel aspect ratios were introduced. Of course that value of 2:1 had been totally off. It still leaves its marks because one still specifies the pixel aspect ratio within VICE i...

I suppose you're referring to the menu option 'Snapshot > Save/stop media file ...' in VICE. In that case, this has nothing to do with your graphics adapter card. VICE always saves the screen buffer contents before any filters (such as rescaling and TV system emulation) are applied. And this screen ...

The low-byte of the jiffy clock is counted up by 1 every 1/60 second, and wraps from 255 to 0. That means, on entry to this sub-routine the byte is either in the range of 0 to 59, and then the routine waits the remaining time until the byte becomes 60 (which already is not constant), or the byte has...

The subroutine mentioned in the posting below should do the trick. :mrgreen: http://sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?t=676&start=17 If you want to implement something like a clock, this would however always add the processing time between the delays into the calculation, so...

I just tried the SPLASH file from your Spidey vs. Doc Ock game. It loads fine without issues. Most of the white colour 'background' is actually drawn from foreground colour, with multi-colour enabled. These cells change to display vertical stripes in hires mode. So far, expected behaviour. If this i...

It is most probably an attribute cell with multi-colour data that changed into hires when you overtyped it with a character. As I wrote in the OP, the attribute cells are tiles of 8x16 (hires) pixels, i.e. the area of 2x2 (small) characters is always affected when the colour RAM needs to be changed....

Nice! 8) Yes, awesome splash screen! Awesome... I love splash screens! I love them too ... :mrgreen:: https://dateipfa.de/.Public/denial/images/minigrafik/spider-man.png ( download ) After you have started a program with a boot loader created from ' makeboot.prg ' in the MG batch suite, MINIGRAFIK ...

Ghislain got the Comet64 to work on the VIC-20 in general with a suite of programs detailed in the thread ' Internet Connectivity with Comet64+VIC-20? (IT WORKS!!!) '. Three years ago, there had been a demonstration of a VIC-20 posting on Twitter that even got broadcast coverage. See the thread ' VI...

eslapion wrote:- Video port

Pin #1 supplies an unstabilized voltage of +6 VDC from the rectified 9 VAC, which may be loaded with a maximum current of 10 mA.