Your problem with output sounds extremely familiar. Is your printer an Epson,
by any chance? It might not really matter. Check the PRINTER! After three
months of screwing around with two different shops, buying and using some
diagnostic hardware/software (which worked quite well, I might add), one bright
soul at the last shop hooked my printer up to an AT. Guess what? Printed
flawlessly. To test a growing suspicion, he then connected it to a brand new
Amiga. No go. Connected a different printer (Panasonic, I think) to that Amiga.
Printed fine. Connected it to my Amiga… same. The bottom line? The printer is
broken… at least the parallel port. Oh yeah, it seems that the AT parallel
port puts out a tad higher voltage than the Amiga… apparently just enough to
overcome the flakey board in the printer. I fixed the entire problem by
constructing a DIN serial cable (the Epson has two ports, centronics and DIN
serial). It's been fine for nearly a year now.
Frank Dlugoleski