Grafix glitches

[vicist]

I recently s-video modded 2 vic-20 cr's and they appeared to be working fine, both displaying great output on my 1901 monitor (pal).
However, the other day I tried a few cart games installed on my sd2iec device loaded to block 5 using k3ys excellent 32k ram expansion. I fancied having a go at Gorf - a cart I have stored away somewhere. This is what I should see followed by what I saw:-



Very disappointed, I dug out the original cart and tried it in the machine - same thing!
I tried another game from sd2iec - A World at War. If you look hard, you may spot a slight difference in the display.

Gamebase V3.0 >>>>>>>>>>>>> Sick Vic


Investigating further, I tried sd2iec loads of more of the carts I have:

Star Battle
Omega Race
Sargon II Chess
Spiders of Mars
Avenger

They all worked fine.

Then I tried some Denial members games.

Bertie the Ball - OK
Pitfall - OK
Popeye - Bad
Pooyan - Bad




Only sd2iec, monitor, 32k ram and joystick are connected.
Any help with this would be great.

[mrr19121970]

What about the 'test card' program?

http://personalpages.tds.net/~rcarlsen/ ... /vic20.txt

UB7 6560-101 VIC VIDEO/AUDIO
White or blank screen, garbled or no video, screen full of (or few
random) "garbage" characters. "Blind" disk commands may still work.
Partial failure: Dark or smeary image, loss of color, garbled or no
sound, game paddles or light pen doesn't work.

UB9 7402 (M53202P) OSC MASTER CLOCK OSC
White screen... no RF interference in AM radio (see text). Partial
failure can produce missing color or incorrect colors, slight or severe
tearing of picture or diagonal lines, sounds play at incorrect pitch.
Symptoms may only appear after warmup.

UC2 74LS04 LOGIC
Screen character colors incorrect (scrambled). If very bad, entire
screen becomes garbled with flashing characters, vertical bars and
random colors.

UD1 CD4066 QUAD SWITCH (LOGIC GATES)
(UC2 in very early version) Screen characters have incorrect colors.

UD2-UD6
UE1-UE6 2114 or TMM314A SRAM MEMORY
Blank screen. Partial failure: less than normal "3583 BYTES FREE" at
startup, sometimes will produce "garbage" screen or screen freeze after
warmup. Shorted chips may get very hot. NOTE: UE1 is used to generate
character color.

[eslapion]

@vicist
The multicolor display mode fails to activate.

This could be caused by problems with the color ram but more likely your 6560 chip is overheating or has been exposed to overheating for extended periods of time in the past. In the latter case, the damage may be permanent.

[vicist]

@eslapion
I wondered if it had something to do with multicolour mode as the problem programs seem to loose certain colours.
But then some of the games I mention, like Bertie the Ball, do none of these use multicolour mode?
Maybe I damaged the 6561 when removing fb7 and replacing with the capacitor as it sits right next to it.
Oh my, what to do? The chip is not socketed and I'm all fingers and thumbs when using a soldering iron.

[mrr19121970]

It costs 18 quid plus postage for a new vic-I chip from mutant catapillar. For this money you can simply buy a 2nd machine on ebay ?

I don't think using a soldering iron for a few seconds a few cm away really is what eslapion meant. Rather prolonged (normal) usage without a heatsink is what he means.

[vicist]

eslapion is right though - I tried

Code: Select all

poke 646,10

to invoke multicolor mode from a cold start and all I got were red characters.

I can still play most of my favourite games with this vic, just not all of them.
I'll have to make a list of what works and what doesn't and the ones that don't I'll play with my old vic on the tv.

Many thanks for your help and suggestions.

I also have a problem with the other vic that I modded, but that's another story.