schaad@gorgo.ifi.unizh.ch ( icu vorstand) (07/06/90)
Hi Folks, I got 2 questions: what are the pin assignements on the serial interface of the HP48sx? (RS232 names, please) The official interface kit is too expensive. Dumb question: are the programs on the serial interface kit disk public domain (I guess not, bu who knows). I refer to the hp48sx progs, not the DOS or Mac progs. If the ARE public domain, would someone post them here? Rene Schaad, Zurich -- ========================================================================= Rene Schaad, Zurich, Switzerland schaad@iis.ethz.ch Zippy for president =========================================================================
jthornto@fs1.ee.ubc.ca (THORNTON JOHAN A) (07/07/90)
Here are the pinouts for the 48SX serial port:
4 3 2 1
/------------|-|-|-|----\
| 48SX | Pin Function Standard RS232 pin eqv.
| ___________________ | (25 pin connector)
| | | | 1 Chassis Ground 1
| | 4: "THIS" | | 2 Transmit Data 2
| | 3: "IS" | | 3 Receive Data 3
| | 2: "THE" | | 4 Signal Ground 7
| | 1: "SCREEN" | |
| ------------------- |
| |
| [A] [B] [C] [D] [E] [F] |
| MTH PRG CST VAR ^ NXT |
| . . . . . . |
If you're making a cable, just make a standard null modem cable.
(reverse RX and TX)
48SX pin RS232 pin
CHG 1 - - - - - - - - 1 CHG Chassis ground does not
actually have to be connected.
TX 2 ------\ /------ 2 TX
X
RX 3 ------/ \------ 3 RX
GND 4 --------------- 7 GND
I have a problem with my cable: the PC won't receive data from the HP.
Anybody have any ideas? The loopbacks work on both sides. I think it
may be a problem with signal levels - the HP supposedly doesn't use
standard RS232 voltage levels. A line driver could be installed to raise
the voltage. Netters?
.sig
>Johan Thornton
>UBC Electrical Engineering