Amiga 2000 - AT keyboard resetQ.

[RichMK]

How does a real A2000 keyboard reset work technically ?


I have thrown this adaptor together and it works well but obviously with no Amiga reset. https://www.pcbway.com/project/share...D_ADAPTER.html


So basically, I just need to know how a real A2000 keyboard sends the reset signal with no dedicated reset pin so I can add it or try to modify the source for the above adaptor.



Any pointers please

[MiaM]

It's a multi stage process.

Pressing ctrl+amiga+amiga makes the keyboard send a reset warning message. The computer can either answer immediately or defer the actual reset for a certain period. When the computer has answered the message or a certain time period has passed, the keyboard will issue the actual reset.

Note that the A500 will do a reset immediately while the A2000/3000/4000, A1200 and CD32 keyboards will use the reset warning sequence. Not sure about A600, CDTV and A1000.

it seems to be fairly well explained here:
http://amigadev.elowar.com/read/ADCD.../node0172.html

A quick search online tells that a keyboard reset will also reset the keyboard itself, so the keyboard won't send all key up sequences. See for example this thread:
https://forum.arduino.cc/index.php?topic=139358.60

[Jope]

You don't have to worry about the reset warning at all in this case. The eventual keyboard reset that happens after all the reset warning malarkey is a pulse of the clock line by the keyboard.

http://amigadev.elowar.com/read/ADCD.../node0179.html

This pulse is detected in hardware by the A2000, so you can take the relevant circuit from the A2000 schematics and recreate it on a piece of breadboard, or even draw a PCB for it.

Page 4 of the PDF https://www.amigawiki.org/dnl/schematics/A2000_R6.pdf