[net.micro.cbm] new printer interface - TURBO/GT

scottm@cavell.UUCP (Scott McPhee) (11/25/84)

 A new printer interface has hit the market and I have had the chance
to examine it, so here are some details.
 
CONNECTIONS - the TURBO/GT uses the serial port (like a standard
              Commodore printer) and also uses the cassette port
              for power. The connection on the cassette port is
              a "transparent" connection, ie. there is a card 
              on the back of the plug so you can also plug in your
              datasette at the same time. Of course, the TURBO 
              offers a centronics type plug and ribbon to go to the
              printer. There is about 5' of serial cord, 3' of 'power
              line' that comes out of the serial plug and goes to the
              cassette port, and about 2' of ribbon cable - enough
              total length to satisfy any set-up.

FEATURES ---- the GT claims faster graphics dumps than leading interfaces
              and even supplies machine code routines in the user manual
              so you can type in graphics dump routines for a series of
              printers.
            -  Speaking of which, there are 3 dip switches accessible from
              the outside of the GT that enable a wide selection of printer
              'groups' which include all the populate names: Expson, Gemini,
              Talysman, Sharp, and on and on and on.
            -  There is a plug in BUFFER option of either 16K or 32K. These   
              buffers  are in similar sized units ( 6" X 3" ) with plugs
              that mate to the side of the GT. Only one buffer may be used
              at a time. ie: no piggy backing. The price of the 16K buffer
              runs the same as the TURBO/GT itself - about $140 (Canadian
              dollars) locally. They claim that 8K of the 16K buffer can
              be filled in about 19 seconds, upon testing, I believe them.
              Actually I filled 10K in the same time by printing long 
              strings out to the thing from BASIC.
            -  I personally own a Tymac "The Connection" interface and have
              to admit that the Commodore graphics characters that the GT
              reproduces are far better - the printed characters appear 
              closer to the 'truth' as seen on your monitor.
            -  The GT will reproduce reversed characters (as in the first
              line of a disk directory) and "The Connection" will not - it
              merely underlines them.
            -  EMULATION of the Commodore 1525, 801 is offered on power up.
              Open 4,4   will behave as if you had a Commodore printer.
              Other secondary addresses offer various listing modes that will
              expand certain key sequences into what they mean - <RED> for  
              example instead of printing the graphics character for red.
            -  There is a built in test command to inspect the state of the
              interface - by merely typing Open4,4,16:print#4

COMMENTS ---- I think the black plastic case is rather flimsey on both the
              buffers and the GT itself. I didn't like the feel when I 
              plugged the buffer into the side of the interface. It made
              sort of a soggy connection feels and the cases "gave" and
              made a snap sound (I thought I broke it but I didn't on
              inspection) and I wasn't really pressing hard. However, the
              buffer worked correctly after it was appended.
            -  If you have a printer that is fast (100 CPS and above) then
              buffers are NOT JUSTIFIED - the saving in time to load the buffer
              is not that substantial compared to printing the file outright.
              I own a Gemini 10X and calculated the speed throughput 
              advantage to be about 4 times. Not that great since I can
              wait one minute and 10 seconds instead of 20 seconds with
              no feeling of efficiency loss. IF you own a LETTER QUALITY
              daisy or the like, then seriously consider at least the
              16K buffer - since a 3K tokenized BASIC program can easily
              expand into 10K of listing.
            -  The manual is good and walks you through setup and explains
              things nicely with fast look up tables for reference.
            -  TURBO carries a guarantee (I think the regular 90 days)
              against defects etc.
OVERALL  I was impressed with the quality of the manual, and results of
         the interface, but didn't like the cheapness of the case and the
         plug-and-wire for the cassette port. The other plugs are good -
         normal centronics and a plastic cased serial plug. The switches
         and external accessibility of RAM buffers is great. There is
         also a RESET switch on the buffer to clear it and reset the
         interface. There is one LED on the GT to indicate power.  
         The GT is a comparable product to the Cardco +G, The Connection,
         and other high level printer interfaces - with nothing really
         substantially better than any of them except for the buffers
         if you have a slow printer.

AUTHOR - Scott McPhee, Software Design at the University of Alberta.