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first of all, understand that I have a very basic knowledge of electronics.
I have a Commodore 64 case and I want to turn it into a USB keyboard.
My approach would be taking a keyboard appart and getting its internal electronics and soldering its pins to a custom made PCB.
But the problem is that all the keyboards I remember taking appart have chips which are connected to the membrane directly and there's no pins available to solder at least not by the hand soldering tool I have.
Is there any electronic kit to make this, or a keyboard chip alone?

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All USB keyboards work by means of a matrix of keys. There is no 1:1 relationship between a pin and a keyboard function. If you examine the membrane you can see how the matrix is made up of columns and rows. Rows and columns are scanned in sequence to find where they intersect at a pressed key.

You will find that (pretty much) all modern USB keyboards use surface mount components and ICs. These can be pretty hard to work with, especially if they are soldered directly on to a flexible PCB.

Ideally you would be looking for an old USB keyboard. One that has buttons that no longer work - ideally it would have been a high quality one in its day. Something quite a few years old - one of the first USB keyboards to be on sale. They are less likely to be using SMD and more likely to have a real PCB inside you can work with. Even if they are SMD they will still have a better chance of having a real PCB.

If you're looking for a chip to completely roll your own, the Alcor Micro AU9410 is a good choice, but alas is (like most similar products) only available as a surface mount device.

A third option is to create your own from scratch. You would need a microcontroller with USB capability (say a PIC18F4455), and some firmware to emulate a "Human Interface Device" (or HID). Microchip have examples in their application library. You can then get that to do absolutely anything you want with the keyboard.

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  • \$\begingroup\$ Yeah, right, thanks for the downvote. Care to tell me why? \$\endgroup\$ – Majenko Sep 2 '11 at 20:57
  • \$\begingroup\$ Some people... Here, take my upvote. \$\endgroup\$ – Mister Mystère Mar 13 '15 at 12:01
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DIY project of how to convert C64 keyboard to PC USB keyboard with just an ATMEL AVR chip can be found here. USB HID protocol is emulated in software, and you don't need any driver since OS automatically recognizes the keyboard and you can use it immediately. The advantage of such an approach is also that if you know a little C (GCC for AVR), then you can customize the keyboard layout to your taste. Basic programmer for AVR chips can be made with just few resistors.

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  • \$\begingroup\$ ooh sounds interesting... gonna investigate \$\endgroup\$ – Petruza Sep 2 '11 at 15:19
  • \$\begingroup\$ How do you like it? \$\endgroup\$ – avra Sep 8 '11 at 10:18
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The teensyduino is an example of a chip which has pins that you can solder connectors for the keys used. Furthermore it has reference software to allow you to use it to build a keyboard. Example: https://github.com/technomancy/atreus.

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    \$\begingroup\$ I'd put disclaimers here, however since it seems that nothing less than a full wholehearted endorsement of a product will be accepted as an answer, you can have this one :) \$\endgroup\$ – J0hnG4lt Mar 13 '15 at 14:50
  • \$\begingroup\$ Great link! That is one splendid looking device! \$\endgroup\$ – P i May 23 '15 at 18:32

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