3 Jan
2009
3 Jan
'09
7:58 p.m.
Tony Duell wrote:
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).
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).
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