uIEC/SD == AWESOME!

[Tony Duell]

> 
> Tony Duell wrote:
> >> Tony Duell wrote:
> >>     
> > If oyou use one switch to select between SS/80 and Amigo (protocol), that 
> > leaves 2 switches for drive type. Not really enough. And what are you 
> > going to do about sleecting the HPIB primary address (HP units normally 
> > had 3 switches for this, allowing addresses from 0 to 7 only).
> >   
> Not sure.  I do have the ability to add an entire latch of switches on 
> the IDE bus (like I am adding the IEEE-488 support.)  On the current 
> unit, you send commands to the unit through the command channel to 
> change such things, so maybe that is another option (pick the command 
> set from the front, then issue a command to pick a device type and 

I think the HPIB address pretty much has to be set in hardware. I suppose 
other options could be set by sending commands to an otherwise unused 
secondary address, but it's a kludge, and I'd rather not have anything 
which doesn't _exactly_ follow the HP command set (for fear some program, 
somewhere, will use some undocumented HP command that happnes to clash 
with the configuration one).

> > FWIW, I've had some early HP HPIB units on the bench recently, and HP 
> > used '38s as driers (open collector) and '14s as receivers (schmitt 
> > trigger inputs). Of course using thsoe put the package count up.
> >   
> '38s are somewhat iffy, in my mind.  MC3446 and the 75XXX line sink 

Quite so. I was just commenting on what HP used in their early devices. 
Later ones used 75160s and 75162s, 3448s, the HP custom buffer chip, and 
so on.

I would be happy to look at any schematcs you come up with for HPIB and 
commetn on them (don't send them to me here, though!). 

-tony