WTB: VIC 1010 Expansion Module

brighty · Post by **brighty** » Sun Jul 20, 2008 11:11 am

I'm looking to buy a VIC 1010 Expansion Module, which is probably as likely as getting hens teeth, but worth a try. I need to run a 3K and a 16K ram expansion together, so this looks like a good option.

Failing that, a 32K+3K switchable ram expansion would be good, but I suspect they are even harder to come by than the 1010!

Anybody with any leads or willing to sell?

Cheers

6502dude · Post by **6502dude** » Sun Jul 20, 2008 11:52 am

Have you considered a MegaCart as an option?

http://www.6502dude.com/cbm/vic20/megacart/ (old & outdated but provides general idea)

http://www.youtube.com/watch?v=fmYe3qql1VQ

http://sleepingelephant.com/ipw-web/bul ... php?t=2073

brighty · Post by **brighty** » Sun Jul 20, 2008 12:10 pm

6502dude wrote:Have you considered a MegaCart as an option?

That looks ideal! Are they available yet and how much does one cost?

Mike · Post by **Mike** » Mon Jul 21, 2008 5:14 am

brighty wrote:I need to run a 3K and a 16K ram expansion together, so this looks like a good option.

Just curious: which program needs these two expansions be present at once?

Michael

brighty · Post by **brighty** » Mon Jul 21, 2008 5:45 am

Hi Mike,

Mike wrote:
brighty wrote:I need to run a 3K and a 16K ram expansion together, so this looks like a good option.
Just curious: which program needs these two expansions be present at once?

Michael

One that I'm attempting at the moment.

I have the screen in 16x8 mode for 22 columns by 11 (ie 22 x 22), and use a raster stable interrupt to switch to 8x8 mode at row 23, displaying a further 4 rows, giving a a total screen real-estate of 22 x 26.

The arrangement is that the 22 x 11 (playfield) is bitmapped with screen ram at $400-$4f1 and character ram at $1000-$1F19 and the 22x4 (panel) has screen ram unchanged at $400, but the raster stable interrupt flips character ram to $1C00, allowing me to use the remaining 13 characters within $1000-$1FFF as custom indicators and to use the "overlapped" character ROM for scores, times etc.

So far, it's the only combination I've managed to squeeze out of the limited range the VIC chip can address. I did experiment with using space in $200-$400, but there's too much sensitive stuff in there to work around.

I realise that if I finish my game based on these requirements that it will seriously limit the accessibility to most (other than emulator users), but to me the purpose is a personal challenge on whether or not I can implement this particular game on the Vic or not. There's no way I could do it with just a 3K expansion, unless I consider a multi-loader style games, but it really doesn't lend itself to long pauses. If I consider an 8K or 16K expansion only, I lose the VIC addressable space at $400-$1000 and the whole screen setup is unachievable.

So, I have this screen setup running stable in VICE, but I would like to test it out on my Vic. I have 3K, 8K & 16K ram expansions already, but I don't have a 1010 to plug two in at once

Mike · Post by **Mike** » Mon Jul 21, 2008 6:11 am

brighty wrote:[...]22x4 (panel) has screen ram unchanged at $400, [...]I lose the VIC addressable space at $400-$1000 and the whole screen setup is unachievable.

The VIC chip can only address the built-in RAM. Sorry. I'd already guessed you'd try something like that.

The VICE emulation is flawed in this regard, as it supports the access of the VIC to $0400-$0FFF, which is not possible on real hardware.

Michael

eslapion · Post by **eslapion** » Mon Jul 21, 2008 6:34 am

brighty wrote:The arrangement is that the 22 x 11 (playfield) is bitmapped with screen ram at $400-$4f1 ...

As Mike said, this works in VICE but certainly not on a real VIC with any expansion.

It is possible to get that to work on a real VIC if you add your 3K expansion internally to the VIC on the other side of the VIC/6502 barrier but it is VERY complicated.

brighty · Post by **brighty** » Mon Jul 21, 2008 6:55 am

Hi Mike,

Mike wrote:
brighty wrote:[...]22x4 (panel) has screen ram unchanged at $400, [...]I lose the VIC addressable space at $400-$1000 and the whole screen setup is unachievable.
The VIC chip can only address the built-in RAM. Sorry. I'd already guessed you'd try something like that.

The VICE emulation is flawed in this regard, as it supports the access of the VIC to $0400-$0FFF, which is not possible on real hardware.

Michael

Oh damn.

Well I draw the line at a VICE only game. I wanted this to run on a real Vic. Sigh. Back to the drawing board. That'll teach me not to test on the real thing first.

Well, I'll have to go away and rethink it all now. Perhaps a less ambitious first game.

Thanks all for the help and heads up! I could have wasted a hell of a lot of time going down this road.

Mike · Post by **Mike** » Mon Jul 21, 2008 7:09 am

If you don't want to touch the lower 1K, 160x192 is the maximum resolution possible. You might try MINIGRAFIK for this.

Greetings,

Michael

carlsson · Post by **carlsson** » Mon Jul 21, 2008 12:30 pm

If you reduce the bitmapped area to 22x10 double height (176x160), you save 352 bytes and will have plenty of RAM left for the single height text lines.

eslapion · Post by **eslapion** » Mon Jul 21, 2008 1:20 pm

carlsson wrote:If you reduce the bitmapped area to 22x10 double height (176x160), you save 352 bytes and will have plenty of RAM left for the single height text lines.

I must admit, that is a great idea.

Using this trick and a rapid swapping of the character set at a critical point in time, it would probably be possible to use interlace to display 176x320.

Does anybody know what trick is used in Bandits (or any other game) to change the char set at a specific scanline?

Added edit:
I recently considered the possibiity of adding a small adapter sandwiched between the 6560 and the VIC's main board to provide S-Video functionality. Maybe I could make a slightly larger adapter that has extra RAM on it to both provide a 3K RAM expansion and make it available to the VIC for extra graphics memory space.

carlsson · Post by **carlsson** » Tue Jul 22, 2008 1:47 am

Again, does really interlace mode on a real NTSC TV or monitor double the vertical resolution?!? I can't see how it can possibly do that. As far as I have understood, the interlace bit just toggles between sending out one half frame of all even lines followed by one half frame of all odd lines, with one full frame of all lines in a row. It can reduce flicker on some TV sets.

I do own an NTSC VIC-20 but only PAL monitor so while I get a steady B&W picture (my 14" TV didn't like the NTSC signal much), I doubt I will ever be able to experience what interlace is supposed to do.

Interlace mode on an Amiga is something different, I admit.

eslapion · Post by **eslapion** » Tue Jul 22, 2008 10:08 am

carlsson wrote:Again, does really interlace mode on a real NTSC TV or monitor double the vertical resolution?!? I can't see how it can possibly do that.

By changing the character set the VIC chip scans everytime the screen is redrawn.

The Amiga, when using interlace mode, scans different areas of memory for even/odd scanlines. You could do the same for the VIC.

Overdoc · Post by **Overdoc** » Mon Jul 28, 2008 10:25 am

These VIC-1010 are harder to get than anything else !
I have been looking for 10 years until I got mine a few days ago

Unfortunately it is missing 3 of the 6 port covers, but anyway, I am happy having one.
The VIC-1020 are easier to come by, but they go for high prices.

Vic20-Ian · Post by **Vic20-Ian** » Mon Aug 25, 2008 1:08 am

How about building a multicart adaptor?

The one I have seems to work fine thought it looks Heath Robinson. A bit of circuit board and three or 4 edge connectors.

PM me for a photo if needed.

Vic20-Ian

Denial

WTB: VIC 1010 Expansion Module

WTB: VIC 1010 Expansion Module

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Re: WTB: VIC 1010 Expansion Module

Re: WTB: VIC 1010 Expansion Module

Re: WTB: VIC 1010 Expansion Module

Re: WTB: VIC 1010 Expansion Module

build a multicart adaptor