serial device emulator

Won't work, no matter what you try! Worse yet, even a pair of real serial ports on the same box, wired up with a null modem cable will *not* provide a suitable emulation.

The problem is that real serial devices are asynchronous and an emulator *cannot* duplicate that. There are always timing issues that require a genuinely asynchronous relationship between the two ends of a serial connection, and as long as the two ends are controlled by the same computer, it won't happen. Whatever you develop will work fine, until you put it on a real circuit...

Hence, the only reasonable platform for serial port program development is to actually use a serial port and connect it to some other device. The "other" device can be an old modem, another computer, or best of all to an example of the device it will actually be used with. A program that emulates your device, running on a separate box, is the best you can do if there are no actual devices yet available.

Lacking that, the "dummy device" that I often use is any old modem that has a fairly lengthy output in response to at least one command. A long stats page, or maybe a dump of the nvram or a list of options. The longer it is, the better; and most of the older higher quality modems are suitable.

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