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HP95LX Serial Port??? Correct email address this time
Message #1 Posted by mike on 9 July 2001, 7:31 p.m.

I'd like to use my HP95-LX with a serial ported DMM. QucikBasic cannot open the port. I've tried every combination of port parameter I can think of. I can transfer files thru the port using the built-in functions, so the hardware is working.

Optimal solution would be an incantation to make QuickBasic v4.5 open the port. I could switch to a different basic if that would help and didn't cost much. Or a TSR that would perform the serial function. Or information so I could peek/poke the serial registers. They don't seem to be in the normal place for a PC. Looking at the pointers in low memory, the serial port seems to be located in the video memory address range??? I don't need a lot of bandwidth to read 14 bytes of dmm data.

I've even considered adding an addressable register that could be used for external I/O. But I'd need some documentation on the hardware, schematics, etc.

Ideas appreciated. Pointer to better place to post this request? Thanks, mike

      
Re: HP95LX Serial Port??? Correct email address this time
Message #2 Posted by David Smith on 9 July 2001, 9:49 p.m.,
in response to message #1 by mike

The '95 LX serial port is compatible with the PC/XT/AT serial port and should be at the proper address. I have written many programs for the unit to interface it with GPS recievers, etc. The same programs run identically on the 95LX and PCs and bang on the serial registers directly. The 95LX serial connector only has the in/out/ground lines connected.

      
Re: HP95LX Serial Port??? Correct email address this time
Message #3 Posted by Chris Randle on 11 July 2001, 1:27 p.m.,
in response to message #1 by mike

The HP-200LX has a setting under communications (in the SysMgr) to "Enable Com1 Port in DOS". I no longer have a 95LX, and I can't remember whether or not it does too. Could this be the reason you can't open the port from BASIC?

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