Conference hydra::amiga_v1

    I use a Digital ABC box for my DigiView and Printer. It works fine.
    Only catch is that there appear to be some grounding incompatibilities
    between the printer cable and the DigiView module that require some
    occasionally tweaking of the cables on the back of the box.
    
    Paul
    

    Does anyone have experience using one of these sort of boxes for
    the serial port?
    
      Mitch

    I am using an LQPX2 serial switch box on my parallel port.  Just
    keep in mind that for a serial device pin 1 is grounded and the
    other 24 pins are switched.  On the parallel port pin 1 is STROBE*
    and must be switched also.  Pin 15 on the parallel port is not used
    so I disconnected pin 15 and wired pin 1 in its place, on all three
    connectors.  This may be the ground problem mentioned in .1.
    
    Pin 14 according to the Amiga manual page A-5 supplys 100mA @+5V.
    
    I would recomend turning off your Amiga prior to switching.  The
    last I heard the 8520 chip was going for around $40 - $50 each.
    There have been a few comments in this notes file about damaging
    the Amiga and or connected device while changing cables with power
    on. 
    
    Alan
    
    

I've got ABCD switches on both my serial and parallel ports.  Works great
for me.  I use it for the following:

       Serial Port:               Parallel Port:
         A: Modem                   A:  Printer
         B: Terminal                B:  Perfect Sound
         C: MIDI                    C:  Digiview (someday, hopefully!)

I haven't had any problems switching with the Amiga turned on, but that
doesn't mean that it's a good idea necessarily.  I doubt that my switches
always break-before-make though; they were cheapies.

...richard

    re .3:
    
    The 8520 costs $17.50 at Memory Location.  I know.  I've bought
    two.
    
      Mitch

    I've got a Digital AB box connecting the serial port to a Scholar and 
    an LA50.  Once a long time ago I switched between devices and the 
    A500 went crazy - lights blinked, the drive began clicking, real 
    scary.  Could have been that both the printer and the modem were 
    turned on at the time.  Now days I keep the printer turned off when 
    I switch devices, and I've had no problems.

    - Cliff

    I have the exact same setup except I use an a1000.  The printer
    may be off or on.  I 've had no problems.

    I have an A-B-C (relatively cheap, purchased mail order from Jim Black)
    and I switch without problem between an LA50 and a Scholar, both
    powered up.  On the other hand, I have them on A & C, with B unused, so
    make-before-break should not affect me.

	Paul

The past few replies refer to switching on the serial port. Has anybody had any
good/bad experiences while switching the parallel port?

Dave

The issues around ports are typically that when you are unplugging
    replugging connectors you may induce two types of hazards - one
    - ground and or supply voltages are disconnected before the signal
    lines and - two - inducing static voltages on the signal lines.
    I have a normal switch connected to the parallel port in order to
    use Digi-view, Sound-digitizer or my laser printer without having
    to switch off and on the computer when changing the device. It is
    a break and then make type which I feel is safer than a make and
    break as you could have the load of both devices at the same time
    when switching. I have not had any problems with it so far.
    The second (better) choice is a electronic switch using
    bi-directional tri-state logic internally there you should not have
    problems at all.
    
    Ernst