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Darshevo
September 7th, 2009, 10:28 PM
I picked this old girl up at the recycler a few trips back and its been rolling around on the floor in my truck ever since. I finally drug it in the house today and popped the keyboard off of it to see what was going on under there. Found the original battery (no leakage thankfully), a 340mb HD and the body of the floppy drive. I picked this old girl up initially with plans to gut it out and build my Commodore 64 laptop in it. Never having really paid attention to the KB itself it occurred to me that its unlikely the existing keyboard could be easily modified to work with the PS2 connector built into the C= DTV unit. Am I off base in thinking that the existing KB will be more trouble then its worth and just get one of those inexpensive compact USB models and convert it to PS2?

-Lance

Chuck(G)
September 8th, 2009, 08:58 AM
Why not pick up a PS/2 keyboard and use it? My local recycler has piles of them.

Darshevo
September 8th, 2009, 12:41 PM
The long term goal is to turn the IBM case into a C64 laptop using one of the joystick 30 in 1 games, a motherboard and screen out of a 10" portable dvd player, and some form of pc keyboard. There is information available on google on how to connect a standard ps/2 keyboard to the C= joystick, I just need to get something small enough that I can whittle it down so it will fit in the small case of the 486 laptop.

-Lance

Chuck(G)
September 8th, 2009, 01:19 PM
That's better--I understand now.

There shouldn't be a lot of difference between a keyboard of that vintage and a modern one. But location of the relevant parts (e.g. the keyboard controller) matters a lot, so a photo or two of the keybaord innards and connections might help to make a solid determination.

channelmaniac
September 8th, 2009, 01:25 PM
Actually there's a HUGE difference... the key matrix will be laid out different. You'll need to build a circuit to interface the 2 different systems... The output of the keyboard and the keyboard circuit on the C64.

RJ

Chuck(G)
September 8th, 2009, 01:56 PM
Actually there's a HUGE difference... the key matrix will be laid out different. You'll need to build a circuit to interface the 2 different systems... The output of the keyboard and the keyboard circuit on the C64.

To my way of thinking, that's a minor item. If you need to translate, you can use an 8 pin PIC or AVR to translate serial datastreams. Other than the time for program development, the cost would be under $2. Heaven knows, someone's probably already done the programming, given the way these things go.

Darshevo
September 8th, 2009, 05:31 PM
Here is a link to the C= DTV wiki that I got my information from. I appreciate all the info and the fact that you guys continue to bear with me as I learn some basic electronics.

http://picobay.com/dtv_wiki/index.php?title=Keyboard_port

-Lance

Chuck(G)
September 8th, 2009, 05:58 PM
Looks as if there's plenty of good information out there and that a PS/2 keyboard will work with a C64 DTV as-is. So how about a photo or two of the innards of the 486 keyboard you want to use?

Darshevo
September 8th, 2009, 07:00 PM
Here is are a couple pics, one of the ribbon cable coming out of the keyboard, and one of the underside of it.

http://retrocomputing.myauctionplace.com/vc_pics/ltkb02.JPG


http://retrocomputing.myauctionplace.com/vc_pics/ltkb03.JPG


I am working my way into the mobo area, when I get it uncovered I will post a pic of it as well

-Lance

MikeS
September 8th, 2009, 07:16 PM
To my way of thinking, that's a minor item. If you need to translate, you can use an 8 pin PIC or AVR to translate serial datastreams. Other than the time for program development, the cost would be under $2. Heaven knows, someone's probably already done the programming, given the way these things go.
It kinda sounds like you're both missing the point a bit; the DTV wants a PS/2 AFAIK so the C64 keyboard matrix is irrelevant, no?
On the other hand, it won't be exactly trivial to get a PS/2 data stream out of a laptop keyboard...
Or am I the one who's missing something here?

Darshevo
September 8th, 2009, 08:08 PM
No, you're dead on MikeS, the DTV expects either an AT or PS/2 keyboard input. My assumption is that the onboard hardware maps the keys as there is literature surrounding the DTV that shows which PS/2 keys map to unique C= keys (such as the run/stop key.

I guess I would have much more clear to have asked if the 486 LT keyboard could easily be converted to either a PS/2 or AT plug.

-Lance

Chuck(G)
September 8th, 2009, 08:19 PM
Now that I've got a photo, it looks to be an uphill battle for you. The keyboard encoding is on the motherboard on the end of those flex cables, not on the keyboard itself. Probably more than you want to bite off at this point--it certainly would be for me. Not that it couldn't be done, but it would be far from trivial.

You never know on some of these early systems and it was worth a shot.

Darshevo
September 8th, 2009, 08:45 PM
When I saw the ribbon cable I suspected that would be the case. The only advantage to the stock KB is that it already 'looks' in place. These hacktop type lap tops are generally always frankenstein though, so it will all be part of the fun. I think I will go with plan B and find a ps/2 kb with a small foot print. Once I get a few more parts together I will start a build thread over in the Commodore forum.

Thanks for confirming my suspicions, saved me a ton of time

-Lance

MikeS
September 8th, 2009, 09:08 PM
I suppose it *might* be remotely possible to connect the keyboard to the module from a regular PS/2 keyboard and then convert the no doubt incorrect scancodes with a PIC or similar. The special keys might complicate things though...

What make/model is the laptop? And what are you thinking about for the display? Using the laptop's LCD would be a real challenge IMHO...

Heresy I know, but if the laptop works why not just dedicate it to one of the emulators?

Darshevo
September 8th, 2009, 10:11 PM
Its a dead player I got from one of the local e-waste places. The LCD is a 10" out of a DVD player. A little trial and error and I found which 2 lines switched to the aux in and wired them together so when the LCD is powered on it automatically goes to the aux in. The DVD player screen isnt really the hot ticket for this kind of project as you have to retain the dvd player mobo.

The laptop is an old Thinkpad 486. Its pretty big, so there will be room in the top for the LCD and that mobo. I will put the DTV stuff in the bottom as well as the battery and SD card reader (which will be emulated as the 1541)

When I get a little further along I will do a full write up in the C= section

-Lance

channelmaniac
September 8th, 2009, 10:14 PM
It kinda sounds like you're both missing the point a bit; the DTV wants a PS/2 AFAIK so the C64 keyboard matrix is irrelevant, no?
On the other hand, it won't be exactly trivial to get a PS/2 data stream out of a laptop keyboard...
Or am I the one who's missing something here?

Exactly...

A laptop keyboard is nothing but a matrix of contacts and ribbon cables. There is no intelligence present on it as all of that is built into the laptop's motherboard. You'll need a PIC/AVR or 80xx microcontroller with a couple of 8 bit (or more) I/O ports to strobe and read the keyboard contacts and translate that to PS/2 talk for the DTV.

If you were using a standard C64 then you'd need to use something that would strobe/read the pins on that keyboard matrix then read the strobes from the CIA chip and output the appropriate signal to make the CIA think it read the real key switch. That would take a lot of pins on a controller to do.