Denial

How common are machines with non-standard ROMs? The Japanese VIC-1001 sports a NTSC KERNAL with extra support for the Hiragana characters in the keyboard driver. Furthermore there is a Swedish (PAL) version, which - again - changes the keyboard layout. There are also the JiffyDOS KERNALs (PAL and N...

Now how cool is this? I had no idea you had registered here on Denial! :D End of last year, I posted a link to your site in the thread ' What is happening here? '. My mothballed VIC has 76.5K inside. If you add in another 16Kx4 SRAM in place of the colour RAM, your VIC-20 would also be able to displ...

Mike: Is it really possible to set the timers for such a tiny interval? Yes, that's entirely possible. The SID Vicious Emulation, for example, uses an NMI at a rate of ~6 kHz. You'd use Timer 1 of VIA #2, controlling the IRQ. The low- and high byte are located in $9124 and $9125, respectively, and ...

Do any of you programming gurus have any ideas on how to improve the timing of the player? As you already should have noticed, the variant execution time of CHRIN introduces a lot of jitter, the delay loop just makes it less apparent (sort of like the current limiting resistor in series to a LED). ...

Good question. What use is it to have a PAL KERNAL in a NTSC VIC-20, and vice versa? http://sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?t=5430&start=17 The table at $EDE4 provides the init values for the VIC registers, and it can easily be used to provide TV system independence: inste...

What tokra said.

Which kind of program are you going to write that actually requires you to differentiate between PAL and NTSC VIC-20s? Just curious.

This seems like a more difficult solution that is necessary. Why did you decide to do it this way? I didn't write the game, but I'll answer your question nonetheless: because it allows to have a multi-coloured player 'sprite' in high-resolution that doesn't colour clash in any way with the backgrou...

Hmm... SourceForge and GitHub spring into my mind here.

I noticed that the stairs are thinner in the original version of the game... is there a reason why in this VIC version they are wider? (not saying that you should modify them of course!) It's a quite simple reason. Many screen elements you are looking at in this implementation of Pitfall do not exi...

[...] speaking of which, I've noticed a lot of recent Vic releases have a nice hi-res loader screen. Does anyone want to code one? Well, even a raw convert of the Intellivision game box into 104x256 FLI already would look like this: https://dateipfa.de/.Public/denial/images/games/pitfall.png IMO, t...

I tried to load it about 5 times with no success [...] That happens because of a wrong load address in the *.prg file. Saved BASIC programs (also ML programs with a BASIC stub) are supposed to start at $120 1 with a +8K (or bigger) RAM expansion. The byte containing 0 at $1200 is not saved along wi...

Here's my remark to the cross-posted copy of the type-in listing in another thread: (link)

Now how about this one?



The marked top-left colour is transparent.

freshlamb wrote:Mike has also uploaded a NTSC version of the VFLI disk and tools.

The archive can be downloaded here: vfli_ntsc_prototype.zip.

As I wrote earlier, the resolution of 184x208 pixels is intended as stop-gap measure until I find time to implement the 168x384i display routine.

Hmm..., this one employs an EOR mask, but it's longer and needs two temporaries: STA temp LSR A EOR temp AND #$55 STA temp2 ASL A ORA temp2 EOR temp If you don't mind undocumented opcodes, you can replace the instruction pair ASL A/ORA temp2 with SLO temp2 . The instruction pair LSR A/EOR temp also ...