[E3-hacking] External keyboard (mailboard) support for 2.6

Cliff Lawson clawson at amstrad.com
Wed Apr 5 18:20:22 BST 2006

> -----Original Message-----
> From: Matt Callow [mailto:mc-lists at tesco.net]
> it's still useful to have. Whilst looking at the code, I noticed that 
> the qwe interrupt handler writes to latch2 
> (I'm assuming AMS_DELTA_HDW_OP_SCARD_2_MASK is 0x400), 
> setting it at the 
> start and clearing it at the end. Is this for debug purposes only? I 
> noticed a similar thing in the FIQ handler using GPIO6.

Yup I *think* they are just being used to tickle "spare" pins to trigger an
LA or a scope. I'm kind of surprised that hasn't been removed in fact though
I'm not sure of the vintage of the tree I have on my machine (and yes it's
> I also notice that the driver has some code for writing to 
> the keyboard, 
> but data never seems to be sent. Is my understanding correct? 
> Does the 
> keyboard accept data?

Well the use of it we make is because the PS/2 keyboard controller has been
known to die (sometimes as often as about once every 5 minutes in fact) -
it's a standard, masked part that we have no control over - so what we do is
send it 0xEE commands and see if it echoes. If it does all is well, if it
doesn't we switch the 5V line to it to reset the chip. But we don't transmit
anything else to it as we're happy with the scanset and typematic rates it
defaults to.


This e-mail and any attachments are confidential and intended exclusively for the addressee. If you are not the intended recipient please delete it from your system and notify the sender immediately. This message is attributed to the sender and may not necessarily reflect the views of Amstrad Plc or its subsidiaries.

For further information on Amstrad Plc please visit our website: www.amstrad.com

Amstrad Plc.
Brentwood House
169 Kings Road
Essex CM14 4EF
Registered in England : No. 955321

More information about the e3-hacking mailing list