EUG PD


An Alternative Driver

 
Published in EUG #4

Introduction

This program creates a View Printer Driver with absolute space facility, for use with any Epson-compatible printer. It is essential to enter it carefully as any errors will only show when your printer refuses to work properly. The resulting object code is given the name occurring in line 880.

Type in the listing and SAVE before RUNning it or your typing will vanish. RUN the program and it will create a printer driver with the name "XX".

  1. To load: On the View command screen, type PRINTER XX, "Printer XX" should appear below MODE on your screen.
  2. To use: The highlights are refereed to as 1 (default underline) and 2 (default bold). Use FUNC + H to switch highlight 1 on/off and FUNC + J to switch highlight 2 on/off. Using the codes in the table below, they can be varied for up to six additional styles. The state of one highlight command does not affect the other.

    To insert a highlight, proceed as follows:
    1. Identify what is to be bolderised or underlined.
    2. Place the cursor at the exact place you wish the bold or underline effect to start and press the appropriate FUNC + "character". The markers that appear (inverse asterisk or hyphen) are not printed.
    3. Repeat for the end of the effect. Once called, a style will stay in effect until cancelled, end of print or not. You have been warned!

    An absolute space is achieved by typing a '£' (pound sign) where a space would occur. The printer driver will substitute a space for each '£'.

Accessing Alternative Typefaces Using View Commands

This method works for all printer drivers once loaded:

  1. Create a new line above that to be highlighted.
  2. Type FUNC + O (cursor to the left margin), enter HT and press RETURN. Having decided which to alter, type 1 for underline or 2 for bold, space, and the three figure highlight code. For example:

    HT 1 130

    will change highlight 1 (FUNC + H) to italic printing. Any line with a HT command in the margin is not printed.
  3. To restore the default values after a change, use the above procedure and code 1 128 to restore normal underlining and 2 129 to restore normal bold. It is quite permissible to mix two highlights (eg. condensed italics) but if all you want is bold and underline, you won't need the margin commands.

Making It Work For You

All printers are different so you may need to change the codes in lines 770 to 840. The codes given are for a Centronics GLP and may not produce the same effect on your printer. Check your manual for the correct sequence for your machine.

Let's assume that "Esc A 0" is required to turn on italics and "Esc A 1" to turn off italics. You can ignore the Esc code, so just convert the rest to Hex ASCII, there is a table in the Electron User Guide to do this. You would find that A=&41 and 1=&31, the pairs being known as bytes. The four bytes written after EQUD are in reverse order, &FF is reference to the control code table and means the next two bytes switch the effect on/off. Thus line 790 becomes:

790 EQUD &3130FF41

You will have to take some time getting all of this right - experimentation is the name of the game, but only you and your printer can do it.

Table Of Marginal Codes

Code Highlight
128Underline
129Bold
130Italics
131Double Strike
132NLQ
133Condensed
134Elite
135Enlarged

The source code accompanying this article is stored in the U directory.

Chris Chadwick, EUG #4

Chris Chadwick