Denial

I want something longer than a second. Let's say three or five seconds. [...] I would use it to set pace/rhythm in a game. If you can guarantee, that all actions up to the next delay take less than around 4 seconds, bit 0 (value 1) in the mid-byte of the jiffy clock might do the job: it changes fro...

I still prefer not messing around with the jiffy clock. For another example, here's the intro sequence of VICtoria Gold Edition: 590 @RETURN:DN=PEEK(186):@LOAD"TITLE 1",DN:T1=TI 600 OPEN2,DN,2,"FILL DATA,S,R" 610 FORR=1TO23:INPUT#2,R$(R,1),R$(R,0):NEXT 620 CLOSE2 630 IFABS(TI-T1)...

Don't bother. I just checked the speed difference between a screen built up from single line PRINTs (without any control characters) and triple-line PRINTs (also without control characters, the last PRINT doing two lines), each done in a loop 100 times: 1 line PRINTs: 1158 jiffies, 3 line PRINTs: 10...

a simple optimization [...] would be to put two drawing lines on a single line of code The converter optimizes already a lot by leaving out {RVS ON} and {RVS OFF} control characters, when they're not necessary. But in the worst case, a single line could still contain 22 control characters, 22 print...

I've been searching memory locations for some value that naturally progresses in such a way that I could use WAIT. I still haven't found anything. This is how WAIT works: it takes up to three parameters, an address, an AND-mask, and an optional EOR-value. The address is read, then bits are toggled ...

After a short exchange with darkatx over PM, I was finally able to find the source of the problem: the @LOAD command continues even when an error occured during load, it then activates the graphics screen automatically, with whatever is present in memory to display. Now, when one makes a typo and en...

Unfortunately, I lose line 0 when I type it as in the screenshot, in Vice. That has nothing to do with VICE, this also happens on a real VIC-20: the cursor must be within one of the physical lines of a logical line to enter that logical line into memory when RETURN is pressed. I suppose you pressed...

Not quite two dozen lines, but nonetheless... here's pgm2chunky.prg ( download ). It expects a 44x46 pixels *.pgm file as input, and emits a *.prg file. A first some initialisations for all possible 2x2 groupings of chunky pixels in string form (G$) and screen code (G%()): 10 DIMG%(15),S%(1,1),C%(1)...

I would never of thought the VIC could display images of such quality. You must have missed the entire development over the last three years, where Torsten and I went all the way up to MAXIGRAFIK , MFLI , MIFLI and - with a small hardware modification - VFLI . Finally, I could feed back some algori...

what I meant was all the four chars that make up the tile are the same colour, each tile can be a different colour. I missed that somehow. You can fetch the tile colour from another table and then put it into another ZP address, changing: STA tile_ptr LDA #0 to STA tile_ptr STA tile_colour LDA #0 i...

Not much faster, and untested, but you might try out this one instead: ; ***************************** ; * Draw 2x2 Tile on screen * ; * A = Tile Number * ; * X = Column 0-20 * ; * Y = Row 0-21 * ; ***************************** STA tile_ptr LDA #0 ASL tile_ptr:ROL A ASL tile_ptr:ROL A STA tile_ptr+1...

Works but a bit memory heavy. This method takes away 2K just for a constant definition of the character set, and then you still have to add in the screen data. IMO, using a bitmap (like MINIGRAFIK/MINIPAINT) or doing 'sparse' hires displays (like Ghislain does in his splash screens) makes better us...

OMG, ML code tucked away in a REM statement...LOL... Take a look here for a similar feat for a joystick decoding routine. ;) You just have to take care, that the ML code does not contain any null bytes, as these would be interpreted as end-of-line (and the two following bytes would be changed by th...

Well there's always cc65, but that's a cross-compiler and different language of course. Most of the speed enhancements of Austro-Comp stem from: - pre-evaluating constants (so it's not 'necessary' anymore to put often used values into variables), - calling the arithmetic routines in the BASIC interp...

This is for unexpanded VIC-20: 0 REMZZZZZZZZZZZZZZZZZZZ 1 FORT=0TO18:READA:POKE4102+T,A:NEXT 2 DATA32,241,215,134,252,165,162,133,251,56,165,162,229,251,197,252,144,247,96 Line 0 contains 19 Z's. Run this once. After this, you can delete lines 1 and 2. Never modify line 0. SYS4102,X with X between 1...