Epson MX-70 TRS-80Model, TRS-80Model, Entering Graphics Mode

Appendix D

We can get around this limitation by POKEing the code numbers directly to the printer buffer, foiling BASIC’s attempts to intercept it. The location we POKE is 14312, so use:

POKE 14312,0

In fact, we could use POKE to send ALL our graphic codes, but this approach creates timing problems between the printer and computer. Every POKE needs to be followed by a test to see if the printer is ready to accept more codes. Example:

10 POKE 14312,0

20 IF PEEK (14312)<>63 THEN 20

Line 20 places the program in a delay loop until the printer is ready.

Entering Graphics Mode

0 is also used to enter the graphics mode. For example:

10 LPRINT CHR$(27) “K” CHR$(50) CHR$(0);

ESC K Nl N2

Since the MX-70 interprets all even numbers as 0, we can change the last part of the above line to

CHRS(2);

The POKE alternate is

10LPRINT CHR$(27) “K” CHR$(50); :POKE 14312,0

20 IF PEEK (14312) <>63 THEN 20

TRS-80 Model II

The MX-70 works fine with Radio Shack printer cable #26-4401. Be sure the connectors on both ends make good contact. It may be necessary to open the printer case a bit to allow the plug to seat properly.

TRS-80 Model III

No interface kit is necessary for the Model III. Simply plug the Epson cable into the printer port.

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