Serial ports in MAME part I

Serial port emulation is a much more intriguing subject than you probably think. I am writing on a number of pages exploring different aspects of the support for serial ports in MAME. The first one is describing what a typical addition of a serial port to a board driver looks like and you can check it out here: serial-port-in-mame.html

Adding the serial port is the easy part, as a board writer you often just find a board that has a similar feature to what your board has and copy the apropriate lines to your driver. However, unless you know how it works the driver will probably not work properly or to the full extent.

In the other end of the RS232 cable there is another device, normally a terminal or a printer but it can be anything. MAME has some default devices that behaves like that class of devices normally behaves.

A MAME top level board driver describes a system rather than a board so the name board driver is somewhat misleading. In MAME you start the board driver and give it configuration options to activate one of many preconfigured devices compiled into MAME that is pre configured to work with that particular driver. For instance there can be a default serial terminal device configured, in which case a terminal window just pops up and starts working without any extra parameters:

./mame fccpu1 -window

There are options that I have not yet explored to connect MAME to a real terminal, this has another set of host related problems that I intend to look at later.