[alt.hackers] Hewlett Packard Image Scanner

armhold@TOPAZ.RUTGERS.EDU (George Armhold) (05/27/90)

Our lab owns an HP Scanjet Image Scanner.  I'm trying to write a driver for 
for our Amiga 2000 using the Amiga's parallel.device.  I can successfully 
execute any commands that don't require the scanner to send any data 
back to the Amiga.  However, any commands that are supposed to return any data 
do not work.  I can send escape codes to the scanner and make it seek, turn 
the light on, and perform a 'scan test', but I can't seem to _read_ any data 
_from_ the scanner.  Any commands that are supposed to make the scanner 
send out data just seem to do nothing.  Does HP use some strange kind of 
handshaking in their scanner?  (I'm using the HP developer manual for the
escape codes, but there is no mention of the hardware interface.)  All the
other machines in our lab (HP PC's and Mac IIcx's) all use HP manufactured
interfaces, so there is no problem communicating with the scanner.

Thanks,
=George