can i test my dot matrix printer melbourne

[Don Gillies]

Hi. I've got a tandy system and a dot matrix printer. The printer doesn't respond to LPRINT, yet it can respond to characters being OUTed. I need to know if my tandy print circuit is faulty, or the printer. Wondering if there's anyone in Melbourne with a working system, who would let me bring my printer round to hook up to your system, and see if my  printer works. If yes, pls email me at gilli...@optusnet.com.au

[Don Gillies]

KNUT-thanks for your email reply. My email software was unable to reply to you, so I'm sending my reply here. Sorry, everyone else. Not sure why I posted my Tandy question to this group-I was confusedly remembering this group from earlier days. My system is a Dick Smith System 80 hooked up to a TRS80 EI via a homemade cable which fixes the incompatibilities between the 2 systems. So it's effectively a TRS80 and runs TRS80 software, but with the joy of looking like a System 80 (Video Genie with Dick Smith label on the outside). You are of course right about the TRS80 using a memory address for printing a character. In my prev message I incorrectly said I was using BASIC's OUT to send a character to the printer. (Not sure why). I was as you suggested, using the TRS80 BASIC's POKE 37E8h. That this works, but LPRINT doesn't, suggests my hardware print circuitry is fairly close to working. I haven't been able to find assembler code for the TRS80 PRINT routine, which would give me a clue to which extra bits of hardware are involved extra to processing POKE 37E8h. I have established the print circuit is reading the status bits sent from the printer, and BASIC is receiving these, so pretty close. LPRINT just sends BASIC off into la la land. All of this is of course no use to you. Just for your interest, maybe. My printer, I bought with condition unknown, hence me wanting to test it on someone's computer before trying to find a fault on the TRS80 EI. Incidentally, if you're interested, Ian Mavric's frehd.com site has a gallery of old timers' computer systems, where you'll find a pic of a Video Genie interfaced to a TRS80 EI (mine)