Subject: Re: NetBSD/pmax WSCONS
To: Andrew Doran <>
From: Chris Tribo <>
List: port-pmax
Date: 03/14/2002 14:56:41
On Thu, 14 Mar 2002, Andrew Doran wrote:

> With the wscons drivers it's possible to hard-wire the definitions into the
> kernel configuration, but if it's indeterminte then that's not too useful.

	It is indeterminite, very rarely they will go to the correct
addresses. The only way I can get it to go where I want it is to unplug
the cords in a certain order and rst's over and over until the chance
reset to the "right" addresses

> Does this reversal ever happen "on the fly" - e.g. while you're typing into
> an xterm? Either way it should be easy enough to solve; ACCESS.bus devices
> are supposed to be able to identify themselves, somewhat like SCSI devices -
> so it's just a case of adding and testing the code to do that. I'll look at
> this soon.

	Well the idea is very similar to USB. Four pins: +5v, Ground, SDA
(Synchronous data) and SCL (Synchronous clock).

Excerpt from ACCESS.bus specification v 3.0


Reset() -> force device to power-up state and default address

capabilities(offset) -> asks device to respond with the information that
t 3/ab/caps shows in the PROM. namely Device name (LK501-AA), type
(Keyboard, locator, text), etc. etc.

assign(ID string, new address) -> assign device X to choosen address

identification() -> asks device for it's ID string

Enable application reports on device X -> allows device to send reports
(data?) to the host computer (e.g. when all devices have been initialized

Presence check -> see if device is still there.

Device->Computer messages

Attention -> Device has finished POST, awaiting configuration

ID reply -> replies with ID string

Capabilities reply -> replies with requested capabilities

	And to make matters interesting, the data format is Big Endian.
anyway this is all useless babble. If you want me to convert the word
documents I have to RTF/PDF/PS and send them to you let me know. The last
word I heard on AB development as that nothing new could happen until the
bus could transmit. Which hasn't been figured out yet I don't think. I
actually never tried to hot swap a device under Ultrix, but when it
flashes the LED's on the keyboard at you it's going though AB
configuration I'm told.