[PD] Pd seriell printers

[Mathieu Bouchard]

On Tue, 3 Mar 2009, brandt at subnet.at wrote:

> Does anybody Know how to control a dot matrix printer troughout the 
> seriell port

First you need to install the [comport] class or any equivalent. It's best 
to use my hacked version because none of the other versions can't handle 
flow-control properly.

Second you need to figure out the wire protocol. Serial port is called 
serial port because it's using the RS-232 protocol, but this protocol has 
many variants and they are not autodetected. For example, you may have to 
say: speed 9600 bits/second, 8 data bits per byte, 1 stop bit per byte, no 
parity, CTS/RTS flow-control.

Third you need to figure out the application protocol. The printer's 
manual may say, for example, that it's an Epson-compatible printer, or it 
may have a switch between Epson-compatible and a different mode. Old 
manuals often give you a list of all commands you can do on that printer, 
especially because they often offer extensions to the standard protocol 
they are basing themselves on, or sometimes because they have a completely 
different protocol.

Most of those printers are based on escape-sequences starting with the 
escape-code ("ascii" # 27), which may sound familiar, but those sequences 
are not related with any of the screen-and-keyboard escape-sequences 
(VT/ANSI) used on BBSes and unix operating systems.

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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal, Québec