On 10/29/2010 12:01 PM, John Chambers wrote:
Does anyone here know what a "bypass code" is? Or how to implement it
on lp5250d for windows?

A "bypass code" is a way to send printer escape codes to a printer without worrying about them being fouled up by the printer emulation software (which converts from IBM printer language to the actual printer language) or the ASCII/EBCDIC translation process.

They used a sequence of &% as a toggle to switch into and out of 'bypass' mode. from there, anything received is in hex. It will be used to fashion actual bytes to be sent as-is to the printer. So for example, you might have this:


The leading &% goes into bypass mode. The 09 (two characters) is used to create a byte containing 0x09, and that's sent to the printer as-is. Likewise the 0a is converted to 0x0a, and the 0b is converted to 0x0b, and they are sent to the printer as-is. The &% ends bypass mode, and things go back to normal until the next &% appears.

Frankly, the whole thing was a kludge. A more proper (and IBM blessed) solution would be to use Host Print Transform. Or at least use SCS transparency codes if you _must_ send raw escape sequences to the printer.

I-O Corporation used these bypass codes extensively in their devices.... I have written software that works with lp5250d to emulate the way I-O handled them.

Unfortunately, my software is for FreeBSD, not Windows. And I developed it under contract, and cannot give it away. But it wasn't terribly difficult to write -- you should be able to write your own.

This thread ...


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