Denial

Was there code already out there, or did you have to do that yourself?

That VIC++ sounds really interesting. How is that project coming?

Wow, that will give something to chew on for a while. Lots of projects and ideas. It looks like you've been a little busy, from the date of that last article. Thanks for the pointer/link.

I have been going through the code from C=Hacking #10 and trying to figure out why each time I start the raster interrupt, the boxes move. The boxes are stable when displayed, they just don't appear at the same raster line when started. ; 10 SYS4109 *=$1001 BYTE $0B, $10, $0A, $00, $9E, $34, $31, $3...

I have also found an error, I think, in the refresh rate calculation that Marko does, in claims that Commodore does not meet the video standard of the time. Marko gives 261 as the number of raster lines drawn by the NTSC 6560, which does give quite a bit of error on the refresh rate. I believe he is...

This VIC 20 has had a lot of work done on it, maybe there's something not making a good connection somewhere.

I see the bit instruction is of no use in this, because the value needs to be stored for the compare that comes later, and that makes the code take up more bytes. ldy #9 bit $24 1$ ldx $9004 txa bit $24 bit $24 ldx #21 dex bne *-1 cmp $9004 bcs *+2 dey bne 1$ I am still curious why the bit instructi...

Would it be more efficient to syncronise to the high bit of $9003? This could be done with a simple BIT$9003, instead of actually reading the register.

I am looking at some code on how to make a stable raster interrupt on the VIC 20, Commodore Hacker #10, and was wondering if anyone can tell me the purpose of the BIT $24 in the code. Is that just a way to burn some cycles?

If I might make a suggestion on removing bad chips, take a pair a small, pointy nose wire cutters and clip the pins off the chip. Then all you need to do is pull the pins out with a pair of needle nose pliars while you melt the solder with your solder pencil. Solder wick does a good job of cleaning ...

I would think the pins that read just under 4 volts are fine, but pin 33 that reads .01 is definitely a problem. Of course there may be more than one chip that's bad, but this is a good start, and hopefully fixes it. I am in the US and would get another 6502 from www.jameco.com. While you are at it,...

If you don't have a logic probe, then you can make a simple tester with a couple pieces of wire, a 470 ohm resister, and an LED. If you are not that technical, then you will have to use your meter. A jumper wire with clips on the ends will come in handy to connect your ground lead of the meter to th...

Pin 7 of that 74LS04 should be ground. If that 14 volts is what you are reading, then I would think you have a bad voltage regulator. From what I have read in some other posts, this may have been caused by that big capacitor going bad. See if you get that same voltage reading across that big capacit...

To start with, you need to make sure there are no blown fuses. My late model VIC has a fuse inside, near the on/off switch. Take a volt meter and check for 5 volts on pin 14 of the 74LS04.

First off, I have a VIC with the CR board in it, I think. Its the later model with two 2K memory chips in it. In preparation for putting a 65816 into my VIC, I have connected the phase 2 clock from the 6560, pin 36, to PHI2 input of the 6502, pin 37. I have also taken the phase 1 clock from the 6560...