Putting Gemini to Work
Transmitting the Codes
The easiest way to transmit functional control codes is to build them into the software program that sends the regular codes for letters and numerals. Sending the control codes to the printer by building them into the program allows you to change the printing instructions during the program. This gives you total control to print what you want, the way you want to print it.
You can also send control codes to the printer using the computer system’s “command level” functions before running a program.
All of this discussion about sending codes for special printing effects should not be confused with the “printing codes and commands” that are a part of commercially available word processing software programs. Word processing programs have
Because of its simplicity, availability, and popularity, we will use BASlC(a computer language) to demonstrate and learn about the Gemini printer. Other languages, such as PASCAL, COBOL, FORTRAN, etc., could also be used, but to keep this training exercise short and simple, we’ll stick to “BASICS?
If you are unfamiliar with BASIC, you might start by turning to the user’s manual that came with your computer. There’s almost certainly a chapter or two about BASIC. You might turn your attention for a few minutes to reading in your computer’s manual about how to set your computer up for running a program in
BASIC.
Internally, your computer uses a binary code (sometimes expressed as “zeros” and “ones”) to convey information. The ASCII codes in Appendix H are decimal(in that they are based on ten numbers - 0 through 9), and hexadecimal (based on 16number mathematical system). In our sample programs, we’ll use the ASCII decimal equivalents.
In BASIC, the CH/?$function is used to convert the decimal ASCII code into your computer’s binary code. Thus,
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