Is it possible to use some spare pins on my ZX24a as an extra serial port to communicate with a second PC? I actually need up to two additional serial ports. Will I need a Max232 or similar IC to make this work?
-Jeff
Need Another Serial Port
The ZX-24a has one hardware serial port provided by the microcontroller that use transistors to drive TX and RX - that is COM1. Others have to be created in software with the DefineCom and other commands. I believe you can add more than one (COM3, COM4, and so on). I believe the limit is 4 additional software ports.The old BX24 was limited to COM3, but that isn't a ZBasic product. Don''t use the DefineCom3 command as it is a legacy item.
Using the Max232 level shifter is often easier and better than building an interface at 0-5volts with transistors, but both are doable options. What likely will not work is direct TTL signals from the ZX-24a to a PC port, while direct signals from the PC port may actually damage the ZX-24a due to being outside the -0.3v to +5.5v range.
It seems that I cannot locate particular specifications for the ZX-24a as it is no longer in production. This seems a recent web site change (removed). I have 4 of them that I intend to use for quite some time. So it might be wise if ZBasic continues to support a legacy documentation effort rather than remove this information. It certainly would mean less effort of having to respond to people one by one.
Using the Max232 level shifter is often easier and better than building an interface at 0-5volts with transistors, but both are doable options. What likely will not work is direct TTL signals from the ZX-24a to a PC port, while direct signals from the PC port may actually damage the ZX-24a due to being outside the -0.3v to +5.5v range.
It seems that I cannot locate particular specifications for the ZX-24a as it is no longer in production. This seems a recent web site change (removed). I have 4 of them that I intend to use for quite some time. So it might be wise if ZBasic continues to support a legacy documentation effort rather than remove this information. It certainly would mean less effort of having to respond to people one by one.
The Taiwanese