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Full Version: HP 85 Serial Interface; INPUT Example?
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Hi.
I have been testing the HP85 serial interface. It works nicely as OUTPUT. However, I have been unable to get any input from the PC side to the HP85. Basically I have been playing with ENTER command.

For instance the following simple sentence does not get any input:
ENTER 10;X
However the following output sentence works well:
OUTPUT 10;X
The value of X is printed on the PC side.

I have been playing with different settings (baudrate, flow control,etc) with same result.

Am I missing something here?

Since you seem to have the ENTER and OUTPUT commands available I am guessing you have an I/O ROM, if you do not you will need one.

Make sure you understand the switch setting in the card they will define the default serial port settings, for instance both my serial cards default to 9600,N,8,1 so SW2 1-4=0 and 5-10=1. The switch settings are documented in the 82939A manual.

Set you terminal to match the serial port setting and enable XON/XOFF, as per manual XON/XOFF is highly recommended for input so that you do not overrun the input buffer. When you have done that the terminal program on Pg 34 of the 82939A manual or page 139 of the I/O Programming manual should work. Read the text that goes with it it should give you some hints about input to the serial card. If you don't have the I/O programming manual I would look for a copy online, it has a lot of useful information in it.