Compaq 5525B/31/32 manual Programmable VFC Using PCL, Example Form

Chapter 2 Configuring the PCL-II Emulation with Control Codes

Programmable VFC Using PCL

Programmable VFC’s using PCL seem to cause a lot of problems and misunderstandings. Most of the misunderstanding concerns the use of the escape sequence used to set the VFC file. This escape sequence is used to override the default VFC of the printer. This escape sequence can be hard- coded into a program or ASCII file.

VFC’s are best understood by reviewing an actual example of how to implement them. For this discussion, the example consists of a 3.5 inch form at six lines per inch with several different channels defined for use on the form to be printed.

1 inch = 6 lines per inch x 3.5 inches = 21 lines; therefore this would be a 21 line form.

NOTE: The TEXT LENGTH command could be used in conjunction with the

standard VFC and accomplish the above requirements. The assumption is there are reasons to use a customized VFC; this example has been simplified for clarification purposes.

First, establish the VFC length: with a 3.5” form and 6 LPI print, we have 21 potential lines of print (3.5 x 6 = 21). Refer to the following figure for an example of the desired finished output.

There are many methods to accomplish this task. The simplest way is to provide a “1” in CH3 (Channel 3) for all possible print lines and simply call CH3 for each line (including blank lines). This is called “line counting” and leaves the burden of positioning with the programmer (adding or deleting a line causes an adjustment elsewhere to be made).

EXAMPLE FORM

Line 1	Company name
Line 2	Street address
Line 3
Line 4
Line 5
Line 6
Line 7	Opening line
Line 8
Line 9
Line 10	Body
Line 11	Body
Line 12	Body
Line 13
Line 14
Line 15
Line 16
Line 17	Closing line
Line 18
Line 19
Line 20	P.S. line
Line 21

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