Subject: Re: hp300 >--HP-IB--< hp300 ?
To: None <port-hp300@NetBSD.ORG>
From: Peter Maydell <>
List: port-hp300
Date: 03/07/1997 20:18:32
Jason Thorpe wrote:
>[ Catching up on mail after being on vacation... ]
>On Fri, 28 Feb 1997 11:00:57 +0000 
> Peter Maydell <> wrote:
> > Assistance/advice appreciated. I've just got hold of a) the TMS9914 data
> > sheet and b) the HPUX man pages on their driver. Is there any good reason
> > not to model a NetBSD driver on the HPUX version?
>I'm not familiar with the HP-UX version.  Can you post a description of

Basically, there seem to be two types of /dev entry. /dev/hpib/#a#
is an 'auto-addressed' device: the first # indicates which HPIB interface
to use and the second # the address of the device on the HPIB. The driver
automatically issues the appropriate TALK and LISTEN commands every time
you write data to them (appropriate control sequences are wrapped round
your data). I think that with these, the driver assumes it's
the system controller. 

The second type is /dev/hpib/# which refers to a 'raw bus' file. The 
# is the interface number, and the driver provides low-level access
to and control of the HPIB. This allows the user to do funky things
like parallel poll, but you have to deal with the addressing of devices
and so on yourself: data written goes to the HPIB unmodified.

Nothing in the HPUX implementation seems obviously broken, but I haven't
programmed with it... Unless anybody who has done so has any objections,
I see no reason to gratuitously break sources that work under HPUX.

Peter Maydell