View Full Version : A500 keyboard problem ...
04-11-2012, 04:57 AM
Greetz from Croatia ...
There's a certain problem with my A500 keyboard and I was wandering if you guys could help me out ... set me on the right track or something.
Amiga works fine. Games load correctly, workbench loads correctly, my mouse, joysticks etc. all work just fine, except the keyboard. And by that I mean just my main set of keys (numeric part of the keyboard works just fine). When I press any of the keys (using CLI or Deluxe Paint for example), the key either presents nothing on the screen or it presents some weird (ascii i guess) character which most certainly is not the character printed od the keyboard key.
Now, the Amiga was a present and behaves like that from the moment I got it, which was a few months ago, and I believe there something wrong with the keyboard, the keyboard controller or something else.
But, is it possible that it's just me, not familiar enough with the platform and that this behaviour is normal because I failed to do something (set the correct keyboard layout, code page, or something else that's more related to software and/or configuration of the machine rather than a hardware failure.)
Any help greatly appreciated.
04-11-2012, 05:54 AM
Do games requiring text input - output the text to screen correctly? If so, it's most probably some whacky Workbench preferences that need setting back to default.
Are you booting directly from Deluxe Paint - or loading from Workbench when you get the garbled text? If you're booting directly from Deluxe Paint then it's most likely a hardware fault. I'm not sure, but a faulty Denise may cause this kind of problem.
Might also be worth inspecting the keyboard to see if there's a key stuck down that would cause the keyboard to output alternative characters.
Also check the keyboard connections on the motherboard - perhaps a dodgy connection could be the problem.
Does the capslock LED flash at all?
04-11-2012, 06:41 AM
Deluxe Paint is loaded from wb. The keys seem allright, no sticky/stuck keys as far as I can see. The connections from the keyboard to the motheboard seem allright as well, but then I'm no electronic engineer so I can't tell for sure. The capslock (red light) turns on/off without a problem. I should also mention the fact that WB disks are originals and came without a read / write protection "cap", so it's imposible to write on them.
I guess it must be a HW problem then. Bummer.
04-11-2012, 10:10 AM
If you load a text editor from WorkBench (say ED or EDIT), and try every key in turn, some return incorrect characters?
So far, it sounds like the keyboard controller chip (the large chip next to the LEDs) has taken a dive. This has happened to me before.
You can replace the keyboard for a modest price from eBay. If you get one that is undesirable in some other way, you can simply swap chips.
Note: you want an A500 keyboard. They are easy to find. The A600 and A1200 do not have this chip on their keyboards.
04-11-2012, 11:15 AM
I have a spare A500 keyboard controller PCB if it would be of any use to you? The keyboard itself died but I believe the controller to be good :)
04-11-2012, 11:54 AM
Here's what I've discovered:
When I load Xcopy from it's own disk, then format another disk, Xcopy asks for a disk name to be enterd in a designated name field. I tried all the keys on a keyboard and they all work just fine. I was able to output every keyboard character on the screen which menas the keyboard is not broken at all. The question, why is it behaving like described earlier inside workbench is a mistery to me. Could it be a virus, or some wb preferences/configuration I don't know how to setup perhaps ?
04-11-2012, 12:48 PM
It could be just that your workbench is loading a keymap on startup that is remapping things oddly. The fact that XCopy is getting proper key input should mean your keyboard is operational. Few things to try
- some other workbench disk
- while booting from workbench disk, tap a few keys as soon as the cli comes up on boot (if it does), and try to catch it before setmap happens. It will interrupt the boot process but you may be able to test out the keyboard.
04-11-2012, 01:02 PM
Will try. Thnx 4 the tip.
If it is a faulty keymap a Replacement Workbench Disk will correct it, If you can indicate your location it's possible some local Amiga user can give you a replacement disk.
04-12-2012, 02:51 AM
Hm. Amiga is German, WB is UK. But, is it possible that some portion of rom was flashed with some codepage settings which are making problems now. But then again, in xcopy everything works fine.
One other thing. I've set up the time and date settings to current (it was June 1st, 1978 when I loaded wb for the 1st time). Amiga was powered off for a few days and when I turned it on, loaded wb, it displayed the correct time and date. How ? It must have saved those settings somewhere in rom, I guess. If that's the case, then maybe some settings regarding keyboard layout/character set must reside inside rom as well. Right ? I'm so unfamiliar with the platform, so I have to ask.
04-12-2012, 05:51 AM
As far as I'm aware you can't save any settings to the kickstart ROM - unless of course your ROM isn't an original ROM - but an EPROM with a customised kickstart.
I'm pretty sure it's how the preferences have been set on your WB disk - the (or 'a') previous owner may have covered the write protect hole up with sticky tape to make it writeable and altered/saved the settings.
The time and date will have been saved by the onboard battery backed real time clock (RTC) on the motherboard or memory expansion card (depends with mobo revision you have) - the battery is usually a rechargeable which explains why it's now held the correct time and date.
04-12-2012, 06:00 AM
Also try booting directly from Deluxe Paint - if the text output is correct, then that will confirm that your WB preferences are at fault.
04-12-2012, 12:44 PM
I've set up the time and date settings to current (it was June 1st, 1978 when I loaded wb for the 1st time). Amiga was powered off for a few days and when I turned it on, loaded wb, it displayed the correct time and date. How ?.
You might want to have a look at that battery and check it for leakage.
If it's an A500Plus you'll have to take the computer apart.
If it's an A500 just open the trap door underneath to gain access to the RAM expansion card containing the battery.
04-12-2012, 02:53 PM
The ROMs of that era cannot be flashed or modified by any means. If you're unsure if you WB disks are any good at all, just format a disk, run 'install df0:' to make it bootable and boot your 500 from there. You'll get a simple shell window where you can check the keys at least.
Possibly the keyboard matrix (within the keyboard) or the controller is damaged but before you start messing with the hardware rule out any software problem.
The clock time is provided by a battery backed up clock (realtime clock RTC). Listen to paul1981 and check the battery - they do leak after a couple of years and tend to eat through(!) the mainboard.
04-12-2012, 05:28 PM
I have had a problem with A500 keyboard, maybe its related. there is a small piece of plastic insulator beneath the PCB; pins can punch through and make a short (to metal shielding). you should check that. I'd try the keyboard in another A500, to be sure its not CIA or something like that. perhaps replacing the capacitors on keyboard PCB would fix it.
04-13-2012, 02:46 AM
Pozdrav ! :)
I rouled out hardware malfunction of any kind, because as I stated earlier, in xcopy, when i have to enter a name for a newly formatted disk, my keyboard works perfectly. It's a WB thing, I think. Haven't tried to CTRL+D it during boot process yet, but I will as suggested earlier.
04-14-2012, 01:00 PM
Well, if this one isn't for ag. Mulder and Scully ... I've found out what's wrong with my keyboard. Ok, maybe I haven't FOUND OUT what's wrong with my keyboard, but what I realised was when I loose up a few screws on the back of the left side of the keyboard, the damn thing works normal. I tried 3 different WB disks, CTRL+D it into shell, nothing helped. A few months of mind phu%ing and three loose screws later, it finally works ! And if you ask me how come it worked in xcopy (every god damn time), I'll direct you to the paranormal investigators mentioned above. Thanks every1 for doing your best and trying to help.
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