Connecting an A500 Keyboard to an A1200 Motherboard

[scrappysphinx]

Hi all, i have acquired two untested 1200 motherboards from ebay for around £8 which both turned out to be fully functioning with 3.0 roms.
I have an old 500 which just goes through a power cycle and never actually boots so i was wanting to try and fit the 1200 motherboard into the 500 case and use the 500 keyboard with it.
I have looked at Jope's A1700 mod here but cannot see which wire goes to which pin.
Could anyone be kind enough to inform me with either a picture or a readme.
I found this one on aminet but its in spanish and allthough i did spanish at school i don't remember a lot of it.

[rkauer]

Originally Posted by scrappysphinx

Hi all, i have acquired two untested 1200 motherboards from ebay for around £8 which both turned out to be fully functioning with 3.0 roms.
I have an old 500 which just goes through a power cycle and never actually boots so i was wanting to try and fit the 1200 motherboard into the 500 case and use the 500 keyboard with it.
I have looked at Jope's A1700 mod here but cannot see which wire goes to which pin.
Could anyone be kind enough to inform me with either a picture or a readme.
I found this one on aminet but its in spanish and allthough i did spanish at school i don't remember a lot of it.

Hello Scrappy.

I notice there are several A500 keyboard to A1200 mobo hacks out of Aminet.

The best I saw is this http://koti.mbnet.fi/udioica/mod_a600lang/index.html . The guy hack an A600 inside an A1200 case using the A500's keyboard.

For you, the interesting part is how to connect the A500 k/b to the motherboard (the very same hack as the 1200).

[laser]

if your A1200 mobo is rev2.B you can do it on a easy way
but if you have an older mobo revision...forget it..you need a special adapter

[scrappysphinx]

Hey Guys, thanks for the replys.
Rkauer i also found this on amiga.org which looks promising so i may try it.
One board is rev 1D.1 and the other is 1D.4

[rkauer]

Originally Posted by scrappysphinx

Hey Guys, thanks for the replys.
Rkauer i also found this on amiga.org which looks promising so i may try it.
One board is rev 1D.1 and the other is 1D.4

1D4 is easier than any other A1200 revision, since the A500 keyboard "connector" is available directly on the motherboard! But it is the buggiest A1200 board.

BTW: that schematic on A.org is simply excellent for future reference!

[Jope]

Originally Posted by laser

if your A1200 mobo is rev2.B you can do it on a easy way
but if you have an older mobo revision...forget it..you need a special adapter

Forget it? No point in shooting everything down right that instant. I believe in sharing the info instead of saying forget it.. Also, look at your post. No real information, merely hints that it could be done. Come on, put some effort into it when "helping". :-(

It's very easy. You connect +5 to +5, gnd to gnd and then CLK and DAT to the CIA chip. The reset signal connects directly to the reset pin on the keyboard MCU on the A1200 motherboard. No special adapters needed, just a bit of wire, a pin strip and some patience.

The resulting "adapter" does not look very complicated at all:
http://jope.fi/a1700_solder.jpg (GND is not yet hooked up in that pic, I took that from the LED header on the motherboard, along with the power and floppy LED signals)

CLK kbd (pin 1) -> pin 44 CIA U7
DAT kbd (pin 2) -> pin 43 CIA U7
RST kbd (pin 3) -> pin 38 keyboard MCU U13 (ok I admit, this one is not visible, but it is not 100% necessary for operation)
+5 kbd (pin 4) -> anywhere where there's a Vcc pin on the motherboard. I took it from the keyboard MCU pin 4, but you could steal it from the floppy drive power connector or directly from the power supply connector or where-ever.
GND kbd (pin 6) -> same as pin 4, take it from the floppy connector or where-ever. I actually took the GND and LED pins out of the keyboard molex connector and plugged then directly into the motherboard LED header, wrapped some duct tape around them for insulation and rode into the sunset.

If you only get ''''s when you type, then you have CLK and DAT swapped around at U7. Desolder, resolder, try it again.

The following taken from A1200exkb.lha, but with CLK and DAT changed around to reflect real life: (if you only look at that lha and nothing else, it doesn't matter as the signals are swapped consistently in that document. if you cross reference, then it becomes a pain, so I will post them correctly here.)

A500:				Ribbon out (usually rainbow)
				    Black=1...Purple=8
					||||||||
			+---------------------------------------+
			|	 Pin 1->........<-Pin 8		|
			|		|||| |		     XX<--Shield Gnd.
			| A500          |||| \Gnd		|
			| Keyboard	|||\+5v		   [===]<--Power LED
			| Encoder	||\_KBReset		|
			|		|\KBDat		   [===]<--Drive LED
			| +-----------+	\KBClk			|
	Ribbon Socket---->|...........|				|
			+---------------------------------------+

  |||||||||||
-+-----------+-
-|           |-
-|           |-
-|   8520PL  |-
-|           |-
-|     U7    |-
-|           |-
-|           |-
-|           |-
-|     ^     |-
-+-----------+-
  |||||||||||
     ||
     | \KBClk (Solder wire here)
     |
      \KBDat (Solder wire here)

NOTE: I suggest you don't desolder the clk and dat legs of U13 unless necessary!
If you don't get anything when you type and you've double checked
everything else, then consider unsoldering and lifting up those two legs.

     |||||||||||
   -+-----------+-
   -|           |-
   -|           |-
   -| Keyboard  |---KBClk (you may need to desolder + bend up)
   -|  Micro.   |---KBDat (you may need to desolder + bend up)
   -|           |-
   -|    U13    |-
   -|           |-
   -|           |-
/---|     ^     |-
|  -+-----------+-
|    |||||||||||
|
\_KBReset (Solder wire here)

I'll go back to my corner and sulk now. I hate the world.

[laser]

yes Jope but that's really complicated...you can damage the mobo if you don't know what are you doing.....
also you must be really carefully ...you must solder on chips

The rev 2.B mobo have the connector ready for any unexperienced newbie

[laser]

Originally Posted by rkauer

1D4 is easier than any other A1200 revision, since the A500 keyboard "connector" is available directly on the motherboard! But it is the buggiest A1200 board.

BTW: that schematic on A.org is simply excellent for future reference!

I think that rev 1D4 haven't any keyboard connector on the motherboard
but maybe Im wrong.....please post a pic

[RedskullDC]

Hi Scrappysphinx,

Originally Posted by scrappysphinx

.....I found this one on aminet but its in spanish and allthough i did spanish at school i don't remember a lot of it.

I recommend you use the spanish mod, it is the least invasive method.

From photo.iff in the file:



This is looking at the underside of the A1200 MB.
The rear of the motherboard is at the right hand side of the pic.

Where you place the KB_DATA, KB_CLOCK,KB_RESET lines is clearly marked. You need to find a source of +5v, and GND yourself.

Cut the two traces where it says: "Cortar estas...cuidado".

With this method you don't need to go soldering legs on the PLCC chips, and it is very easy to reverse the mod if you want to go back to using the original 1200 keyboard.

Hope this helps.

Red

[scrappysphinx]

Hey Guys, thanks for all the replys.

Jope, i followed your guide above and i did have to lift the legs of the u13.
The keyboard is now soldered on and is functional however the caps lock, the shifts, alt, amiga key or the tab keys don't seem to work. The Caps Lock does flash on and off when power is turned on but i cannot get it to work when using workbench.
I also have an a500 with a different keyboard which has the same problem. Is this looking like a problem with the keyboards or the amigas?

Mike

[Jope]

Originally Posted by scrappysphinx

I also have an a500 with a different keyboard which has the same problem. Is this looking like a problem with the keyboards or the amigas?

Mike

I'm afraid the keyboards have some kind of problem..

As you can see, the kbd talks to the computer using only two wires, so if any keycodes come through, then that part is ok.

It may be that the traces on the contact membrane are corroded, or perhaps the keyboard controller in the A500 kbd is somehow knackered. Since you disconnected the A1200 controller, it can't be sending conflicting keycodes at the same time either.

Did you try booting to the initial cli with no startup-sequence? Still the same symptoms when you try to type stuff into cli?

[scrappysphinx]

Hi Jope,

Did you try booting to the initial cli with no startup-sequence? Still the same symptoms when you try to type stuff into cli?

Not sure how to do this bit, i am still a learner when it comes to the amiga but am having great fun along the way.

i have tried to boot a workbench floppy disk and use the shell feature to test the keyboard and i have also installed the green amiga alien version of classic workbench and again used the shell to test. In both environments all keys work fine apart from the ones mentioned earlier (amiga, alt, tab, caps lock). I just find it very strange since i owned 2 perfectly working 500's and one faulty one but all 3 keyboards worked fine and now 2 seem to have developed this same problem.

Thanks for your help so far

Mike

[Graham Humphrey]

To boot without a startup-sequence, simply hold both mouse buttons while the Amiga is booting, and from the menu that should appear click on "Boot with no startup-sequence" (or whatever it happens to be called, can't remember, I'm not totally sober right now).

[laser]

btw,

it's a great idea insert another keyboard on the A1200 because the original A1200'keyboard have several design bugs

lot of keys are blocked by other keys and lot of games can't be played using the keyboard because this stupid design...also if you type very quickly you will found that some keys are not typed....(key block)

it's a pitty that the A500 keyboard doesn't fit well on the A1200 ..the case can't be closed because the circuit and leds located there...
I think that the A4000 keyboard is ideal for the A1200 cause it will fit and it's free of bugs

[Graham Humphrey]

I don't know what they were thinking of with the A1200 keyboard. It's ridiculous some key combinations actually don't work.

[Jope]

The A1200 keyboard itself is 100% the same as the A500 keyboard (ok, the flexi comes out from a different position). You can even hang an A500 keyboard controller board off the A1200 keyboard's flexi cable and it'll work. :-)

I know you meant the keyboard controller, though and I agree. I guess someone got a good deal on those MCUs and they decided it's worth their while and money to do the firmware for the new chip. Too bad they didn't look at what they did with the old one!

[gklinger]

As everyone probably knows (and is sick of hearing) I've been attempting to connect a North American CDTV keyboard to a 1200 and I was forced to use a 500 keyboard membrane. I was going to bridge the flexi-cable to the 1200's flexi-cable input (somehow) but if I do so will I still experience multi-keypress lockouts because they're the fault of the 1200's on-board keyboard controller rather than the keyboard itself?

Perhaps I'm better off using the keyboard controller that came with the 500 keyboard and connecting it as described above. It certainly would be a heck of a lot easier than building a flexi-cable to flexi-cable bridge.

[Zetr0]

Originally Posted by gklinger

As everyone probably knows (and is sick of hearing) I've been attempting to connect a North American CDTV keyboard to a 1200 and I was forced to use a 500 keyboard membrane. I was going to bridge the flexi-cable to the 1200's flexi-cable input (somehow) but if I do so will I still experience multi-keypress lockouts because they're the fault of the 1200's on-board keyboard controller rather than the keyboard itself?

Perhaps I'm better off using the keyboard controller that came with the 500 keyboard and connecting it as described above. It certainly would be a heck of a lot easier than building a flexi-cable to flexi-cable bridge.

this was the post i was going to rustle up for you,

Honestly its the best way, infact not only will it reduce brain swelling it will also mean less work

[gklinger]

Originally Posted by Zetr0

this was the post i was going to rustle up for you

Thanks, Zetr0. I'm asking a lot of questions but I have been making attempts to find answers for myself by reading all previous discussions on the matter.

Honestly its the best way, infact not only will it reduce brain swelling it will also mean less work

I'm all about that. Will using the 500's keyboard controller fix the multi-keypress lockout problem? That's the one thing I'm not sure about.

[rkauer]

Neither I. Tell us when you did it.