Rhomaios Posted April 7, 2015 Share Posted April 7, 2015 I don't have any C64 joysticks, so I thought I'd pop in an Atari one. Only one direction seems to be working, but it works fine on an Atari. Any idea what the problem might be? Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted April 7, 2015 Share Posted April 7, 2015 Do you have other working sticks to test on your Commie? How well does your keyboard work? You could have a popped 6526. Quote Link to comment Share on other sites More sharing options...
Rhomaios Posted April 7, 2015 Author Share Posted April 7, 2015 Do you have other working sticks to test on your Commie? How well does your keyboard work? You could have a popped 6526. Keyboard works just fine. I can get all directions working in controller port 2, but then the fire button doesn't work there either. I tested it with a CX40 and it has the same response as the Wico. Quote Link to comment Share on other sites More sharing options...
landgraf Posted April 7, 2015 Share Posted April 7, 2015 Port#2 firebutton is wired in parallel to the keyboard matrix row containing 9, I, J, 0, M, K, O and N. If some (preferably all) of those keys work the problem is most likely somewhere between the joystick connector and the 6526 at U1. Could be corrosion of the connector pins, broken traces/solder joints or blown protection diodes (if those are present at all, not all boards have them). Quote Link to comment Share on other sites More sharing options...
Rhomaios Posted April 8, 2015 Author Share Posted April 8, 2015 Thanks. Bad news indeed. I would need to replace this by desoldering it and soldering a new one, right? Is there anything I should keep a look out for? Quote Link to comment Share on other sites More sharing options...
carlsson Posted April 8, 2015 Share Posted April 8, 2015 It depends on the phase of the moon. Sometimes the 6526 chips were socketed, sometimes they were soldered directly to the board. Which generation is your C64, i.e. is it an early breadbox, later breadbox, C64C, C64G etc? Actually you have to open it up and have a look to be certain, as the use of sockets was not consistent for one motherboard revision or even factory. If you have to desolder it, strongly consider adding a socket instead of soldering in a new chip. Also the two 6526 chips in the C64 are equal which means if they're socketed, you can swap them and see if you get other faults, like floppy drive and/or RS-232 (seldom used) malfunctions. If you like to read up a little on what is going on behind the doors, here is a brief memory map. Scroll down to the 6526 area starting at $DC00 to learn more about data ports, data direction registers and more. Basically you only need a brief idea which bit does what to match with your issues. http://zimmers.net/anonftp/pub/cbm/maps/C64.MemoryMap 2 Quote Link to comment Share on other sites More sharing options...
Rybags Posted April 8, 2015 Share Posted April 8, 2015 Before getting new chips or desoldering, it's probably worth testing a game or two with the keyboard removed. Some key combinations can cause problems but not register keypresses, sort of a long shot but worth a look. Definately put sockets in for chips you replace, extra 80 cents to save a bunch of time later. Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted April 8, 2015 Share Posted April 8, 2015 Good God, I remember stacking 6526s on each other for testing and sometimes "fixing" a chip which was soldered to the board. Of course, this would not work if the particular port pin was stuck closed (logic low,) which now I think of it I never actually ran across -- failures were either stuck open or tri-state (probably the latter, but I had no way of telling.) Sockets, yes. Quote Link to comment Share on other sites More sharing options...
+save2600 Posted April 8, 2015 Share Posted April 8, 2015 Have you tried touching up the solder joints on the joystick ports yet? Quote Link to comment Share on other sites More sharing options...
hwrd Posted April 22, 2015 Share Posted April 22, 2015 I recently bought some Sega Genesis controllers to use with my C128. There is an issue with Genesis controllers and the CBM computers, and the F7 key stopped working while the Genesis controller was attached. The reason I mention this is "is it possible that someone else used a Genesis controller on your machine and cooked a chip?" FYI, I found a diode fix for the Genesis/Commodore issues, and will be fixing my controllers... Quote Link to comment Share on other sites More sharing options...
Muzz73 Posted May 15, 2015 Share Posted May 15, 2015 I had a first generation 64C back in the 80's and the down direction went out on joystick port #2. It turns out that one of my 6526's was bad, so I bought one from my local C= dealer and popped open the 64C to find out that ONE of the chips was socketed and the other was not. Take a wild guess which one had gone bad... Quote Link to comment Share on other sites More sharing options...
Oge Posted June 16, 2015 Share Posted June 16, 2015 I recently bought some Sega Genesis controllers to use with my C128. There is an issue with Genesis controllers and the CBM computers, and the F7 key stopped working while the Genesis controller was attached. The reason I mention this is "is it possible that someone else used a Genesis controller on your machine and cooked a chip?" FYI, I found a diode fix for the Genesis/Commodore issues, and will be fixing my controllers... Diodes are not enough and you have to check for fast ones that have a high drop voltage. You need to modify the wiring in a manner that renders inoperative the internal TTL IC of the Sega Gamepad (elsewhere you will get +5V shorting to GND when you press buttons). Cheers, Oge Quote Link to comment Share on other sites More sharing options...
hwrd Posted June 21, 2015 Share Posted June 21, 2015 Diodes are not enough and you have to check for fast ones that have a high drop voltage. You need to modify the wiring in a manner that renders inoperative the internal TTL IC of the Sega Gamepad (elsewhere you will get +5V shorting to GND when you press buttons). Cheers, Oge Thanks, much apreciated. I find to find the article iwth the diode setup (I bought the diodes, but GOD BLESS MY PROCRASTINATION). When I locate the artcile, I will post it here. Quote Link to comment Share on other sites More sharing options...
Rhomaios Posted July 21, 2015 Author Share Posted July 21, 2015 So, anyone have a place I can nab two 6526es? Quote Link to comment Share on other sites More sharing options...
zylon Posted July 21, 2015 Share Posted July 21, 2015 http://www.ebay.com/itm/MPS6526-Original-Commordore-6526-CIA-40P-DIP-NMOS-IC-2-pcs-/291426542903?pt=LH_DefaultDomain_0&hash=item43da602537 That one's still fairly easy to find as long as the old DIP-40 is what you need. 1 Quote Link to comment Share on other sites More sharing options...
Muzz73 Posted July 21, 2015 Share Posted July 21, 2015 http://www.ebay.com/itm/1pcs-MOS-6526A-6526-DIP-40-/181412107643?pt=LH_DefaultDomain_0&hash=item2a3d01157b Unless you want go through a liquidator and buy them in bulk... 1 Quote Link to comment Share on other sites More sharing options...
motrucker Posted July 27, 2015 Share Posted July 27, 2015 I had a first generation 64C back in the 80's and the down direction went out on joystick port #2. It turns out that one of my 6526's was bad, so I bought one from my local C= dealer and popped open the 64C to find out that ONE of the chips was socketed and the other was not. Take a wild guess which one had gone bad... I use a couple of Sega Genesis gamepad on my C-64, but I have modified the gamepads so they can't hurt the computer. There is some info here: https://atariage.com/forums/topic/182983-so-can-i-safely-use-sega-gamepads-for-all-9pin-type-consolescomputers/ That may be helpful 1 Quote Link to comment Share on other sites More sharing options...
Muzz73 Posted August 6, 2015 Share Posted August 6, 2015 That's awesome! Thanks for sharing this! Quote Link to comment Share on other sites More sharing options...
motrucker Posted August 23, 2015 Share Posted August 23, 2015 Here is an interesting cartridge for checking your keyboard or joystick circuits. I have dealt with this seller quite a few times, and know him from Lemon 64: http://www.ebay.com/itm/COMMODORE-64-64C-Keyboard-Joystick-Tester-Cartridge-/161697378210?hash=item25a5ea2fa2 I haven't used this myself, but boulderdash stands behind all of his products. After I modified the Sega pads (six button models no less) I decided I didn't like using them. I prefer real joysticks. I usually use TAC 2 or slickstick joysticks. These are some very hearty joysticks, and can usually be found on ebay and other places. THis is, of course, only my opinion - for what it's worth. Quote Link to comment Share on other sites More sharing options...
Raticon Posted December 10, 2015 Share Posted December 10, 2015 I used a Sega Megadrive / Genesis controller on my C64 since i saw it had the same connector without reading up on it. Resulted in me sentencing my 6526 to death by the electric chair... Luckily one very helpful soul on a Swedish C64 forum sold me another chip for pennies, bless him. Oh and it was socketed as this is a C64c which made the swap a piece of cake. 1 Quote Link to comment Share on other sites More sharing options...
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