g – a multitasking OS for Ultimem/VICMIDI (WIP)

[pixel]

the regular KERNAL has to stay in unless somebody is crazy enough to write a replacement, I guess.

At least g should be aware of JiffyDOS in place of a standard KERNAL.

True. SJLOAD as a g library.

[Mike]

True. SJLOAD as a g library.

Well, SJLOAD != JiffyDOS.

When there's a JiffyDOS KERNAL installed, SJLOAD isn't anyhow needed. SJLOAD consists of routines which were extracted from the JD KERNAL so the JD protocol could be used with JD aware drives (including SD2IEC variants) without the necessity to actually install the JD KERNAL. Legal implications on the use of SJLOAD set aside, this soft-loadable version of the JD routines also has the advantage that it (of course) retains the tape routines ...!

[pixel]

Damn! Copyright! But there's a simple solution to wanting things: ask.

[beamrider]

Not wanting to poor cold water on your endeavours, but I think you'll be able to count the number of users on your fingers for a GUI on a 30+ year old computer with limited screen real estate and that requires custom hardware.

[pixel]

Not wanting to poor cold water on your endeavours, but I think you'll be able to count the number of users on your fingers for a GUI on a 30+ year old computer with limited screen real estate and that requires custom hardware.

The bets are on! But I can live with that as long as it gives me a convincing illusion of mental health.

[Mike]

With a hobby as obscure as ours one anyhow needs a lot of instrinsic motivation to follow through with any non-trivial project.

Otherwise I wouldn't have even started out on something in the order of my VFLI mod, had I known in advance up to today there would only be TWO confirmed instances of a modded VIC-20!

[beamrider]

had I known in advance up to today there would only be TWO confirmed instances of a modded VIC-20!

and does that include yours?

[Mike]

and does that include yours?

Yes. No " ".

A meta-discussion about this mod can be found here.

[pixel]

If it makes another single person's worry wrinkles go away – priceless.

[Mike]

In any case, the price for being the first one to reproduce the mod is already given out.

Everyone else may kick himself in the butt, when he follows up - and realizes what he missed out on all those years.

[pixel]

The early bird catches the worm. Which is great if you like worms. (Beer is far too cheap in Germany.)

Here's the new program/library layout:

* Size of symbol/address index. (libs only)
* Symbol/address index. (libs only)
* Destination address.
* Size of code.
* Code.

g is millimeters away from loading and linking but I prefer to freeze my ass off on the bike to get more cheap German beer. :p

[eslapion]

Shower worked wonders – 160x192 it is! Thanks, Mike!

Wouldn't that pose problems on NTSC VIC-20s ?

[pixel]

Ouh! Näh! Coffee will remain my favourite.

Banking really puts a strain on the stack. In the first version libraries won't be reused even if already loaded. Who'd ever need more than 1Mb RAM anyway.

[pixel]

Shower worked wonders – 160x192 it is! Thanks, Mike!

Wouldn't that pose problems on NTSC VIC-20s ?

How did they do 200 line NTSC C64s then? Not so much a difficulty. Despite: windowed apps are nicer when resizeable.

[eslapion]

How did they do 200 line NTSC C64s then? Not so much a difficulty. Despite: windowed apps are nicer when resizeable.

The VIC-20 and C64 don't really respect broadcast norms. The NTSC VIC-20 has a slightly lower vertical resolution than the NTSC C64.

The PAL VIC-20 can display much more pixels vertically than the NTSC VIC-20 and I do remember this posed problems with a couple of games in the past including Frogger '07.

The VIC-20, unlike the C64 has a variable number of rows and columns on display. Add to that the fact that the PAL system allows more scanlines than NTSC and you've got an intersting special case. I suspect, since the PAL C64 has the same resolution as the NTSC C64 that the PAL VIC-20 can display a higher vertical resolution than both versions of the C64 and the NTSC VIC-20.

I think Mike and other programmers took advantage of that along with the interlace capability which is also specific to the VIC-20 for VFLI displays.

The default display of the VIC-20 is 22 cols x 23 rows. On the NTSC VIC, you might be able to add 2 lines of text if you allow for vertical overscan, on the PAL VIC, you can easily add 10 lines of text with the right settings.