RS232 Online User Manual

Timex Computer Interface RS232
(C) Copyright of TMX Portugal, Lda.

1. Introduction

The Interface RS232 enables you to connect your TC2068, TC2048, or ZX Spectrum computer, to a serial printer, enabling you to use the qualities of that kind of printer.

2. Install

Here you must have:
-TC2068 (*), TC2048 or ZX Spectrum
-TV or composite monitor
-Timex 2080 printer
-RS232 cable
-Tape recorder
-Tape with RS232 software

(*) by using TC2068, you must use the Spectrum emulator cartridge or the Time Word word processor cartridge.

Now you must do:
1º connect the computer as showed in the manual
2º connect the Interface RS232 to the edge connector of your computer
3º connect  the RS232 cable to the printer and the Interface RS232
4º configure the printer, using the printer manual to:
        1200 baud
        No parity
        1 Stop bit
        CR+LF
5º turn on the printer and last the computer
6º LOAD the program that is in RS232 tape with:
        LOAD “RS232”

Note: This program has auto-start.

Now you must certify that the routine is functioning properly. For that, start to put your printer online and then type the following instruction:

        PRINT #7;”test”

the printer should respond by printing the word test on the paper.

3. How to use the RS232 Interface

3.1 For the user in Basic

After LOADing the program, it puts in de address 65100, being protected from any basic program.
Warning: When using the NEW command, you must type RANDOMIZE USR 65100 to initialize the printing routine.

For the user to use the Interface RS232 very easily it is established a way of communication very simple.
This way channel 7 was associated with the Interface RS232 to communicate with the printer. Just use instructions directed to channel 7 with #7.

3.1.1 Direct commands do the printer:

PRINT #7;”test”
PRINT #7;”test”; TAB 1;”test”
PRINT #7;A$

3.1.2 Commands to list programs

LIST #7
LIST #7,100

3.1.3 Adapting the printing routine to a program

To include the printing routine using the Interface RS232, in a basic program, is necessary to include this instructions in the main program:

CLEAR 65099
LOAD “RS232.OBJ” CODE 65100
RANDOMIZE USR 65100

These instructions reserve space for the machine code routines and start channel #7.

3.2 For the user in machine code

The programmer can use directly the routines, in the same way as other channels. For that, just:

LD         A,07            ;channel 7
CALL    1601H         ;open the channel
LD         A,”A”           ;send character “A”
RST      10H             ;to current channel
RET

In the above example, the sequence sends character “A” to the printer and then it returns to the main program.
When you want to use the printer in graphic mode, you must call it directly. You can do it, for example:

LD        A,0FEH        ;byte 0FEH
CALL    FE72H         ;send the byte to the interface
RET                          ; return to the main program

To send more bytes through the Interface RS232, you can use a identical program:

               LD         HL,buffer                ;address of the text
               LD         B,bufend-buffer      ;size of the text
LOOP     PUSH   BC
               LD         A,(HL)
               CALL    FE72H                     ;send the character
               POP      BC
               INC       HL
               DJNZ    LOOP                      ;last character?
buffer      DEFM                                   ;”printer test”
bufend    EQU     $