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Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Tue Feb 13, 2018 8:31 pm
by mrtinb
gammaray wrote: Tue Feb 13, 2018 7:40 pm I hope I am not hindering that
In no way. I appreciate your interrest.

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Tue Feb 13, 2018 10:33 pm
by gammaray
Is /RD (The first purple wire on the left) shorting to /WR (The first unattached pin on the left )?
RD PIN Screenshot_2018-02-13_15-24-18.png
RD PIN Screenshot_2018-02-13_15-24-18.png (394.24 KiB) Viewed 3892 times

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Wed Feb 14, 2018 12:16 am
by gammaray
Don't think D5-D7 should be grounded without a resistor...

Maybe need a momentary pushbutton for /CE on EPROM? Set DIPSWITCH. Press button.

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Thu Feb 15, 2018 2:35 am
by gammaray
I noticed that some chip pinouts do not show active high or low. I added this in case anybody wants since others pointed out.

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Tue Mar 06, 2018 10:54 am
by mrtinb
Creating a keyboard is a hard task. To be ready for ZX-Team meeting this weekend, I need a keyboard.

I've changed paths twice. First trying to rebuild an old Mac USB keyboard. This was a pain, as the matrix is plastic foil membrane. I tried with aluminum foil and electric paint. This was a steep hill.

The secord change of path was rebuilding an old Commodore 64 keyboard. It was difficult, as the matrix was completly different. And the board was also difficult to solder on. But finally it worked.

I need to clean the old keyboard before this weekend, but Yes! it works.

Image
Image

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Tue Mar 06, 2018 11:19 am
by mrtinb
Creating Wilf's AT keyboard is still on my to do list. But currently I just needed a keyboard fast.

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Tue Mar 06, 2018 5:12 pm
by msch
cool ... maybe it is a good idea to shift the first two rows some positions to the left ;-)

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Tue Mar 06, 2018 6:31 pm
by mrtinb
It was difficult because the Commodore has a different matrix than the ZX81. If I shifted the keys the task would have been twice as difficult. Then none of the existing matrix could have been used. This “easy” path made it possible to create the keyboard before this weekend’s meet up on a tight schedule. The positions of the keys are irritating, but better to type on than my previous keyboard. (https://sinclairzxworld.com/viewtopic.php?f=7&t=1793)

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Tue Mar 06, 2018 7:44 pm
by msch
Yes, I know that. Some years ago I started my own keyboard project (with cherry switches) but due to the lack of time it is still in development :oops:
Joachim in the german forums has build a pretty cool one (with self designed pcb) - see here:
http://forum.tlienhard.com/phpBB3/viewt ... =25#p30755
I think You can see it in Mahlerts next weekend.

Re: My first wire wrap: Wilf's AT keyboard interface

Posted: Tue Mar 06, 2018 10:26 pm
by gammaray
It is a keyboard that prints in ITALICS! :lol:

Glad you got it working!