Atari CX85 Numpad (USB modified

[jalli]

Figured I'd post this hack.

Found an old Atari CX85 on Ebay for $18, splurged on a Teensy 2 and wired it all up.

Layout/Firmware can be found on https://github.com/jalli/tmk_keyboard/tree/master/keyboard/cx85

[nubbinator]

What kind of switches does it have?  And how long did it take you to figure out all the code for it?

That's such a cool little project.  I actually really love the layout of that.  The 3x +/Enter is a little wonky and it's sad it's missing the other parts of a numpad, but that's a pretty awesome little retro box and a cool little project. 

[kaltar]

Love it!!! So damn cool!!!

[sth]

What kind of switches does it have?  And how long did it take you to figure out all the code for it?

That's such a cool little project.  I actually really love the layout of that.  The 3x +/Enter is a little wonky and it's sad it's missing the other parts of a numpad, but that's a pretty awesome little retro box and a cool little project. 

http://deskthority.net/wiki/Stackpole_switch_grid

[jalli]

What kind of switches does it have?  And how long did it take you to figure out all the code for it?

That's such a cool little project.  I actually really love the layout of that.  The 3x +/Enter is a little wonky and it's sad it's missing the other parts of a numpad, but that's a pretty awesome little retro box and a cool little project.

There are some great shots of the PCB and switches in here:
http://atariage.com/forums/topic/155452-hacking-the-atari-800-keyboard-cx85-keypad-onto-a-usb-pc-keyboard-circuit/

The Caps have the same cross as the Cherry MX but the stems are a bit wider so they would not fit an MX switch without shaving the outside. On the plus side any Cherry MX Caps will fit the CX85.

It took about a day to figure out all the wiring and the grid, soldered the PCB end and then used a breadboard to test everything out before soldering permanently.

It's a nifty little box, I've been thinking about transplanting some caps from my Televideo set: http://geekhack.org/index.php?topic=49503.msg1071064#msg1071064 since they are compatible.

[Lostwave]

I know this thread is old.  But I have one of these and am thinking about doing this.

Just a couple of questions, looking at the code, it looks like you skipped all of the CX-85s controller.  Did you wire the Teensy directly to the buttons on the CX85?

I was kind of hoping to do it without destroying the board, i.e. hooking to the board the same way the atari db9 plug did.

Any help would be appreciated.

Thanks

[jalli]

Hey,

I actually skipped the controller entirely, it's been a while but if you have any specific questions I can probably take the box off and check.

[Lostwave]

A while ago I picked one of these on ebay for $25, its New Old Stock, never been used.  They have more if anyone is interested. 
http://www.ebay.com/itm/CX-85-Atari-Numeric-Keypad-New-NOS-White-Box-800-XL-XE-/140954304589?pt=LH_DefaultDomain_0&hash=item20d188004d

I managed to make this work without hacking it at all, I can put it back to stock by unplugging the teensy from the mainboard, and hooking the stock atari cord back up. 

The hardest part was to allow it to use media keys, thats way more complex than it needs to be.

Just wired a teensy to the mainboard and wrote my first teensy program.  Amazingly it worked.

Source code here: https://github.com/Lostwave/cx85

[TheSoulhunter]

Awesome! Like that "longcat" enter XD

[solderdad]

I have a CX85 and want to do this.  I cannot find a clear diagram of how to wire in the Teensy 2 to the keypad.   Anyone have this diagram handy?

[Findecanor]

The CX85 was supposed to connect to the Atari 8-bit computer over a joystick port.
When a key is being pressed it provides a keycode on the input pins while grounding the trigger pin (joystick fire button).
It is explained in the manual.

[Tactile]

I have a CX85 and want to do this.  I cannot find a clear diagram of how to wire in the Teensy 2 to the keypad.   Anyone have this diagram handy?

This is found in "matrix.c", one of the source files linked in the OP.

Code: [Select]

// Ports for Teensy 2 / CX85
// row:     PB0-4   (pins 0-4)
// row order:    4   2   3   1   0
// row pins:    PB0 PB1 PB2 PB3 PB7
// col:     PD0-3   (pins 5-8)
// col order:    5   8   7   6
// col pins:    PD0 PD1 PD2 PD3