peraino@gmu90x.gmu.edu (peraino) (03/14/90)
>From sterling@cbmvax Fri Mar 9 09:47:01 1990 > > > I called HP Service and get the following info... use it at your own risk! > > Pin Function RS-232 equiv > 1 Chassis Ground pin 1 > 2 Txd pin 2 > 3 Rxd pin 3 > 4 Signal Ground pin 7 This got me to wondering; The serial interface (cable) was designed for going from hp48 to a pc, mac, etc. Basically, serial to serial. This implies that what HP is selling is a null-modem cable with pins 2 & 3 reversed on the other end. This would mean that you CANNOT use HP's cable to go from the 48 to a real modem. Anybody have any info. on this? > Rick Sterling Commodore Technology Group (215)-431-9275 > Test Engineering UUCP ...{uunet,allegra,rutgers}!cbmvax!sterling ----------------------------------------------------------------------------- Bob Peraino UUCP : uunet!pyrdc!gmu90x!peraino George Mason University INTERNET: peraino@gmuvax.gmu.edu UCIS, Thompson Hall, rm 2 <- BITNET : peraino@gmuvax 4400 University Drive \ PHONE : (703)-323-2549 Fairfax, VA 22030 \- Yeah, they put us in the basement, too. -----------------------------------------------------------------------------
smithj@jacobs.CS.ORST.EDU (Jeremy Smith) (03/14/90)
> From: peraino@gmu90x.gmu.edu (peraino) > > This implies that what HP is selling is a null-modem cable with pins > 2 & 3 reversed on the other end. This would mean that you CANNOT > use HP's cable to go from the 48 to a real modem. Anybody have any info. Simply plug in another null-modem cable, or anything that essentially switches lines 2 & 3 back again! I have tried this and managed to get my modem data light to light up (i.e. stuff was getting through).
ge@kunivv1.sci.kun.nl (Ge' Weijers) (03/15/90)
peraino@gmu90x.gmu.edu (peraino) writes: >>From sterling@cbmvax Fri Mar 9 09:47:01 1990 >> >> >> I called HP Service and get the following info... use it at your own risk! >> >> Pin Function RS-232 equiv >> 1 Chassis Ground pin 1 >> 2 Txd pin 2 >> 3 Rxd pin 3 >> 4 Signal Ground pin 7 > This got me to wondering; The serial interface (cable) was designed >for going from hp48 to a pc, mac, etc. Basically, serial to serial. >This implies that what HP is selling is a null-modem cable with pins >2 & 3 reversed on the other end. This would mean that you CANNOT >use HP's cable to go from the 48 to a real modem. Anybody have any info. >on this? You can do it, but it needs a weird conversion plug. You need to set the modem to ignore all handshaking, but that's all. I did this for a comparable setup, using a Z88-PC cable and this conversion plug, a male-to-male null-modem (technically it's not a nullmodem because the handshake lines are connected in a weird way. I'll post the 'schematic' tomorrow. Ge' Weijers Ge' Weijers Internet/UUCP: ge@cs.kun.nl Faculty of Mathematics and Computer Science, (uunet.uu.net!cs.kun.nl!ge) University of Nijmegen, Toernooiveld 1 6525 ED Nijmegen, the Netherlands tel. +3180612483 (UTC-2)
bgribble@jarthur.Claremont.EDU (Bill Gribble) (03/27/90)
Could someone who has hacked up a serial cable for their 48 send me a pinout for the hp's serial port? I'd like to do it, too - I'm pretty sure hp's charging substantially more than the <$10 in parts it will cost to make one. Thanks! ============================================================================= ===== Bill Gribble Internet: bgribble@jarthur.claremont.edu ===== ===== Harvey Mudd College wgribble@hmcvax.claremont.edu ===== ===== Claremont, CA 91711 Bitnet: wgribble@hmcvax.bitnet ===== ===== (714) 621-8000 x2045 ===== =============================================================================
rhelps@yoda.byu.edu (03/28/90)
>Could someone who has hacked up a serial cable for their 48 send me > a pinout for the hp's serial port? I'd like to do it, too - > a pinout for the hp's serial port? I'd like to do it, too - > parts it will cost to make one. Here it is. But first a disclaimer. Hewlett Packard will not support home-made connections and niether will I. If you try this you accept ALL risks of possible damage Pin numbering (unofficial). Lay the calculator on the table and look into the port. Number the pins 1-4 from left to right. Pin number 4 is closest to the IR leds. 9 pin AT style RS232 connector. HP connector 2 (Rx) 2 3 (Tx) 3 5 (Gnd) 4 ----- 1 (Chassis ground ??) I also shorted pins 1, 6, 7, and 8 on the nine pin connector. I'm not sure if this is strictly necessary but it works. The most difficult job is finding suitable connectors for the HP plug. They are neither standard size nor standard spacing. I found some slip-on connections at my local electronic supply store that work well. I had to squeeze them a little with pliers to get a tight fit and I used Heat-shrink tubing to insulate them and provide them with rigidity. Whatever you use BE GENTLE. If you make a mistake you will have an expensive repair job on your hands - not to mention the trauma of being separated from your calculator for awhile. One consolation though, The owners manual at the back implies that if you accidentally short some pins no damage will result. The Kermit transfer protocol works well. I use Procomm which is available as shareware on many bulletin boards. Just use standard upload and download procedures and select Kermit as the protocol. This cable works with my own programs as well as those on the HP bulletin board. I had a lot of trouble initially and thought it was the cable but it turned out to be the XMODEM corrupted files discussed earlier on this network.
erakah@tnetxa.ericsson.se (10/05/90)
Is there anyone who can explain to me how the serial cable to the HP48SX
is connected?