mitch@noscvax.UUCP (Ray Mitchell) (02/26/86)
I am interested in interfacing an Epson printer to a TI-99A computer. I have the technical manual for the computer but timing diagrams and address maps are not sufficient to do the interface. I understand that the printer connects to the computer I/O port and must somehow intelligently respond to a poll from the computer before the computer knows a printer is connected. I need a complete description of what I/O connector signals are used and what type of protocol is used. I have talked to TI on this but they refuse to release the information. I would also like to know what type of keyboard keyin is required to send something to the printer. Any additional information on interface requirements for a disc, the RS-232 interface, and the rest would be appreciated. Thanks, Ray Mitchell NOSC code 911 :w
haddock@ti-csl (03/02/86)
Ray,
The only way I knew that a printer could connect to the
99/4a was either thru the serial port or the parallel port - both (I
think) were available on the serial box (choo-choo train type) and
the serial card that fit into the expansion box. So far as the
serial connection goes, the following table can be used to determine
how to connect your Epson printer to the 4/a. I know it's possible
as I've done it but it's been a coupla years since I've played with
my /4a's. A good 1-to-1 cable with male DB-25 connectors on both
ends will work - I just checked.
So far as timing diagrams and schematics try finding either a
Heathkit store or a good electronics supply store. It would be
there that you should find "Sams Photofacts" and there is one for
the 99/4{a} which contains schematics and other whatnots. If it
isn't in the store you or the proprietor can order from "Howard W.
Sams Publishers".
=====================================================================
TI TRS TI Epson Hayes
Profs Model I 99/4a MX-80 1200
=====================================================================
gnd | gnd | | | gnd || 1 - Ground
o | o | i | o | i || 2 - TXD Transmit Data
i | i | o | i | o || 3 - RXD Receive Data
o | o | | | || 4 - RTS Request to Send
i | i | o | i | o || 5 - CTS Clear Send
i | i | o | i | o || 6 - DSR Data Set Ready
gnd | gnd | gnd | gnd | gnd || 7 - Ground
i | i | o | i | o || 8 - DCD Data Carrier Detect
o | | | | || 11 - SCR/CH
i | | | | o || 12 - SCF/CI (H1200 = High speed ind)
i | | | | || 15 - TXC
i | | | | || 17 - RXC
o | o | i | o | i || 20 - DTR Data Terminal Ready
i | i | | | o || 22 - RI Ring Indicator
o | | | | || 23 - SCR/CH
o | | | | || 24 - BAUDOUT
F | M | F | F | F || Type of connector on machine
================================================================
*hardcopy* *electr{onic, ic}*
Rusty Haddock ARPA: Haddock%TI-CSL@CSNET-RELAY.ARPA
POB 226015 M/S 238 CSNET: Haddock@TI-CSL
Texas Instruments Inc. USENET: {ut-sally,convex!smu,texsun}!ti-csl!haddock
Dallas, Texas 75266 VOICE: (214) 995-0330