Chameleon V2 not working with C64

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Don't Panic. Please wash hands.
  • I just got my Chameleon V2 today and have been playing around with it. I flashed it with the latest 0.9i firmware using Chaco. It seems to work fine in standalone mode, but when I plug it into my C64 and switch to Basic there is no blinking cursor and typing does nothing. Run/Stop-Restore does reset though. If I load a program from disk it will run just fine (usually). I have a "breadbin" style C64 with the 6567R8 VIC chip manufactured 21st week of 1984. Main board is ASSY 250407 ARTWORK 251137 REV C. Is there anything that can be done to make it work? Also, I found that Jamie Fuller's C64 Portal game won't run in standalone or as a cartridge.

  • portal runs fine for me... what kind of problems do you see with it?


    your description is a bit confusing to me... you can use the menus, use it start programs/games... and they will work? but when you select "reset to basic" it will not?


    what you could try is disabling "copy roms from c64", save config, and restart (powercycle)

  • portal runs fine for me... what kind of problems do you see with it?


    your description is a bit confusing to me... you can use the menus, use it start programs/games... and they will work? but when you select "reset to basic" it will not?


    what you could try is disabling "copy roms from c64", save config, and restart (powercycle)

    Portal does run okay for me in both modes, I had turbo mode turned on by mistake. I'm still having the problem where basic is frozen. I cleaned my cartridge port with a brush and IPA. I turned off copy ROMs too. Whenever I press F3 to "Reset to Basic" I get the normal C64 V2 header with memory free and the READY. prompt. There is no blinking cursor, and when pressing keys on the keyboard, nothing happens. Games will load and run just fine though, it's puzzling me.

  • I found this little bit of information with Google:


    U1 906108-02 (6526) CIA Startup screen normal, but no cursor. No keyboard or control port access. Partial failure: some keys or joystick positions don't work, one character appears ahead of startup cursor, screen fills at startup as if keys are being held down. Cartridge works.


    and this:


    U17 906114-01 (82S100PLA) PLA Blank screen, no border. It can produce colored screen or flashing color garbage instead of startup screen. It can cause intermittant loss of cursor, screen freeze and/or program crashes after warmup and it can put random characters on screen. This chip normally runs hot. It is the most common chip to fail in the C64 and it should run no hotter than the SID.


    So I desoldered my 6526 CIA (U1) today and added a socket, then replaced it with an 8520A that I had in my junk bin from an old Amiga 500. The problem still remains. I also ordered a CPLD replacement for the PLA on eBay today. I'll see if that has anything to do with the problem. If anyone has any ideas what might be going on, please let me know.

  • uuuuh. first of all, if your C64 works without the chameleon, it should work with the chameleon. if it does NOT work without chameleon - you shouldnt even try with the chameleon.


    then, the 8520 CIA used in amigas is NOT compatible with the 6526.

  • My C64 works fine without the Chameleon. The 8520 CIA worked in it as well, at least the keyboard worked fine, and it booted ok. I admit this is a very strange problem and I have no idea what might be causing it, unless maybe the PLA is starting to fail. The previous owner had cut out the original PLA and dead-bug soldered a new one to the old pins. I removed the chip and the old pins and installed a socket today. I'll see if a new PLA makes a difference.

  • Well, I got my new PLA today and installed it. The Chameleon still doesn't work when I reset to Basic. Basic programs will run when loaded from the SD card, but the keyboard doesn't register with the operating system. I was probing the address bus with my oscilloscope and notice that 3 or 4 of the address lines are not going fully low, only drop to about 2.5 volts on a low transition. I tried removing the SID and the VIC but it makes no difference, they still don't go fully low. With the cartridge removed, probing those address lines shows them going fully low. Running the C64 without the cartridge, they also go fully low. I'm stumped as to what might be causing this. I think I might need to socket the 6510 and try removing it to see what happens.

  • *shrug* the keyboard does work in the menus though? that really doesnt make sense to me (the menu is running on the very same system afterall). could you try enabling the turbo in basic? then its really totally the same (in menu the turbo is always on)


    edit: could you please also try the vic20 core?

  • I wrote a little Basic program last night to peek and poke the CIA, and it works. I can see the keys being pressed when I scan the key matrix, but pressing Run/Stop doesn't break execution. I can see the CIA being accessed with this program using my o'scope too. When I reset back to Basic, there is no chip select happening at the CIA. Address bus bits A12 and A14 never go below 2.5 volts with Chameleon installed. Without the Chameleon, they go fully low. I removed the CPU last night and put it in a socket. Those address lines still don't go low even without the CPU. I replaced U13 on the board as well, thinking maybe it was pulling the bus high. Still no luck. I connected a milliammeter to ground and measured the current required to pull A12 and A14 low and it measured 1.6mA. I'm just about out of ideas. Is it possible the bus transceiver on the Chameleon is damaged? I'm not looking forward to soldering/desoldering that one.

  • Okay, I now realize that I may have been chasing after a non-issue with address bus bits A12 and A14. I think what I was seeing was the bus floating during tri-state, not an actual logic low, since there is no reason for the Chameleon to access addresses below 0xD000 during normal operation. What's also strange about my problem is that the PS/2 keyboard won't work in Basic either. The OS is not even polling the CIAs. My Basic program can read and write to the CIAs just fine though. I don't know enough about how the kernal operates to figure out why it's not reading or writing to the CIAs.

  • Could it be the IRQ line that has issues? If there is no IRQ there also will not be any keyboard scanning.

    Hooray! You guessed it! The previous owner of my C64 (I bought it on eBay last year) had cut the original PLA out and soldered a new one on the cut pins. He must have damaged the IRQ trace underneath going over to the cartridge slot. I soldered a jumper wire across the bottom of the board and it's working great now! Thanks for helping me out guys!

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