Building the HP49G Serial PC-Link Cable by E.Carta Version 1.20 Warning: This is *NOT* a Hewlett-Packard official page. I assume no responsibility about any damage you could get by following these schematics. 0. Index. * 0. Index * 1. Introduction * 2. Pinout assignment (read carefully!) o 2.1. HP49G-10pin Connector o 2.2. DB9 Connector (RS-232) o 2.3. DB25 Connector (RS-232) o 2.4. PS/2 Connector * 3. Building the cable o 3.1. Project #1: Recycling an old motherboard connector or a mouse cable o 3.2. Project #2: Using the HP38 serial PC-Link cable o 3.3. Project #3: Using the HP49-HP49 cable you get with the calculator o 3.4. Project #4: Using the HP48 serial PC-Link cable o 3.5. Project #5: Using the HP48 PC-Link by building an external adapter * 4. Testing the cable o 4.1. HP49 RS-232 Loopback Test * 5. Using different connectors o 5.1. Using a DB25 connector o 5.2. Using a PS/2 connector * 6. Getting the software * 7. Cable FAQ * 8. Related documents * 9. Obtaining the last version of this document * 10. Contacting the author of this document 1. Introduction. In these pages you find several projects to build from yourself a fully-functional HP49G cable, without having to buy the original one. All the schematics and the projects are from me. With each of these cables you'll be able both to share software between the HP49G and your PC, and to perform the flash-ROM upgrading. * Please read carefully the pinout assignment section. * Be sure to check your cable before using it! 2. Pinout assignment. * I assume the calculator as a DTE, so RX means data TO calculator, while TX means data FROM calculator. * Data from/to the PC are called DATA-OUT and DATA-IN, respectively. * Pinout numbering is different (mirrored) in Male and Female connectors. So be careful!!! * Please read carefully the schematics below; for further information, refer to: http://www.geocities.ws/hpcables/hpcables.htm 2.1. HP49G-10pin Connector * Connectors are seen in front view, with the HP logo on their top. * The male connector in the upper-side of the calculator is seen in front view (LCD screen on the top) in this way: LCD SCREEN /|-----------------------------|\ | +---^-----------------+ | |____| ..... 2 DATA-IN RX 8<----------------3 DATA-OUT GND 9-----------------5 GND Testing the cable Back to index 3.2. Project #2: Using the HP38 serial PC-Link cable. What you need: any HP38-compatible serial cable. The HP38 has the same pinout of the HP49G. So, you can use safely any HP38 cable in your HP49G (for example, F1207B, 8120-6736 or F1897). Anyway, check the cable before using it. Testing the cable Back to index 3.3. Project #3: Using the HP49-HP49 cable you get with the calculator. What you need: The HP49-HP49 serial cable you get with the calculator (part/no. F1633-66000), a DB9-F connector and a DB9-M connector. Building the cable: * Cut the HP49-HP49 cable in two half; * You'll find three coloured wires (RX, TX and GND) and a outer conductor (the SHIELD); * Solder one half (what you want) to the DB9-F and the other to the DB9-M (schematics on below). NOTE: the two half are reciprocal (the output of the first is the input of the second and vice-versa). * The first half, with the DB9-F is the HP49G PC-Link you need. * You plug the second half into the first (from the DB9-side), and, voilą, you get your original HP49-HP49 cable like it was before cutting! Schematic: FIRST HALF SECOND HALF HP49-F DB9-F HP49-F DB9-M SHIELD (6)---------------(SHIELD) SHIELD (6)---------------(SHIELD) TX 7---------------->2 DATA-IN TX 7---------------->3 RX 8<----------------3 DATA-OUT RX 8<----------------2 GND 9-----------------5 GND GND 9-----------------5 Pinout numbering is different (mirrored) in DB9-M and DB9-F connectors! Be careful! Testing the cable Back to index 3.4. Project #4: Using the HP48 serial PC-Link cable. What you need: a DB9-F connector and the HP48 serial PC-Link cable. In this section (and in the next) I'm referring to old models of cable. Newer models (like F1207B, 8120-6736 or F1897) has an adapter to use them with the HP38. So you can use them safely in your HP49G too. For these newer models, see section 3.2. Assuming you own an older model (like F1015-80002). This cable was born for the handheld computer HP200LX, then was sold with an adapter (5181-6643) to use it as official HP48 PC-Link. NEVER (**NEVER**) plug this cable directly in your HP49G. You could damage it! To use this cable with the 49G, you need to modify the DB9-F pinout (this section) or to build a DB9-DB9 adapter (next section). Building the cable: * Using a knife, cut the DB9-F connector from the serial cable; * Solder a new DB9-F connector, with a different pinout. Schematic: HP49-F DB9-F SHIELD (6)---------------(SHIELD) TX 7---------------->2 DATA-IN RX 8<----------------3 DATA-OUT GND 9-----------------5 GND Testing the cable Back to index 3.5. Project #5: Using the HP48 PC-Link by building an external adapter. What you need: some wires, a DB9-M and DB9-F connectors and the HP48 serial PC-Link cable. In this section (and in the previous) I'm referring to old models of cable. Newer models (like F1207B, 8120-6736 or F1897) has an adapter to use them with the HP38. So you can use them safely in your HP49G too. For these newer models, see section 3.2. Assuming you own an older model (like F1015-80002). This cable was born for the handheld computer HP200LX, then was sold with an adapter (5181-6643) to use it as official HP48 PC-Link. NEVER (**NEVER**) plug this cable directly in your HP49G. You could damage it! To use this cable with the 49G, you need to build a DB9-DB9 adapter (this section) or to modify the DB9-F pinout (previous section). Building the cable: * Build the DB9-DB9 adapter (see schematic below); * Plug the DB9-F termination of your serial cable to the DB9-M connector of the adapter and connect all in this way: +-------+ +-----------------+ +----------+ | HP49G |<---------------><--| DB9-DB9 ADAPTER |-->| COMPUTER | +-------+ HP48-PCLINK +-----------------+ +----------+ Schematic of the DB9-DB9 adapter: DB9-M DB9-F SHIELD (4)---------------(SHIELD) TX 8---------------->2 DATA-IN RX 7<----------------3 DATA-OUT GND 9-----------------5 GND Pinout numbering is different (mirrored) in DB9-M and DB9-F connectors! Be careful! Testing the cable Back to index 4. Testing the cable. Before using your new cable for the first time, check it! What you need: a ohmmeter (or a multimeter or a similar device). No matter what method you've followed. The cable you use MUST have: * A HP49G 10-pin connector (or just a 3- or 4-pin connector) on one side, and a DB9-F on the other; * A schematic like this (check with the ohmmeter): HP49-F DB9-F SHIELD (6)---------------(SHIELD) TX 7---------------->2 DATA-IN RX 8<----------------3 DATA-OUT GND 9-----------------5 GND * If you use pin #6 (on the HP49G-10pin side), connect it to the shield. Otherwise, don't connect it (SHIELD is not mandatory). * All the pins should be insulated each from the others and each from the SHIELD (except pin #6). Check with the ohmmeter!. * Perform the HP49 RS-232 Loopback Test (see next section) * DON'T USE cables with a different schematic. To fix the problem, read carefully the pinout assignment of the connectors and the schematic of the cable you are building. 4.1. HP49 RS-232 Loopback Test To perform the RS-232 Loopback Test: * Connect to your HP49G the cable you've built, and let the DB9-F floating (i.e. don't connect to PC); * On HP49 press ON-D followed by F5; * Follow the on-screen instructions. To CLOSE the RS232 ring, simply shunt PIN 2 & 3 in the DB9-F using a piece of wire or a folded clip. If you get RS-232 TEST OK in the upper side of the screen, the cable is probably well done. Otherwise, check the cable. (see previous section). 5. Using different connectors. 5.1. Using a DB25 connector If you want to plug the cable to a DB25 serial port, you should modify the projects above in this way: HP49-F DB25-F SHIELD (6)---------------(SHIELD) TX 7---------------->3 DATA-IN RX 8<----------------2 DATA-OUT GND 9-----------------7 GND 5.2. Using a PS/2 connector If you want to recycle a cable with the PS/2 6-pin connector at its end (for example, an old mouse cable), you should modify the projects above in this way: HP49-F PS/2-M SHIELD (6)---------------(SHIELD) TX 7---------------->2 DATA-IN RX 8<----------------6 DATA-OUT GND 9-----------------3 GND Now you need a PS/2 to COM adapter, in order to plug finally the cable in a COM port or your PC. Don't connect the PS/2 cable directly in the PS/2 port (mouse port): it won't work, and you could damage the motherboard or the calculator itself. The adapter you must use, should connect at least PIN 2, 3 and 5 on DB9 side, like this: (Schematic taken from Microsoft X03-55560 adapter for Wheel Mouse) PINOUT ASSIGNMENT: PS/2-F DB9-F SHIELD----------------SHIELD TX 2--------------->2 DATA-IN RX 6<---------------3 DATA-OUT - 5----------------4 - GND 3----------------5 GND - 5----------------6 - - 4----------------7 - (Thanks to Giovanni Casoli for providing this information). 6. Getting the software. HP49G already includes in ROM the communication software. Read Appendix A of the user's guide or go to http://www.hp.com/calculators/hp49 for more information. So you only need the software for your computer in order to connect it with the HP49G and transfer files and flash-ROM upgrades. All the required software is FREE (please read the provided GNU general public license). * The official HP Graphing Calculator PC Connectivity Kit, distribuited by Hewlett Packard, available for free: http://www.hpcomm.org . Also includes the Flash-ROM Download Program. * HP-PC Link Programs at http://www.hpcalc.org . * The good old Kermit (what I use): http://www.columbia.edu/Kermit . 7. Cable FAQ. These are the most frequent questions I have received. Read carefully before asking for help. If you still cannot solve your problem, feel free to contact me. Q: Can I use these cables to upgrade the flash-ROM? And where can I get the communication software? YES, you can use the cable to upgrade the flash-ROM. For getting software, please read section 6. The required software is available directly from HP, for FREE downloading. Q: I don't own a ohmmeter. What project could I do? Sorry, but you need the ohmmeter for each project. If you haven't one, just ask for help to any electronics shop (like Radio Shack). Q: What is the SHIELD? Should I connect it? The SHIELD is simply the metallic shell in the outer part of each connector. The shield wire (when present) is the outer conductor you find into the cable after having sliced it. You can choose both to CONNECT and DON'T CONNECT the shield. Only, don't let it floating near the connector pins ! Q: Texas Instruments calculators cable use a resistor and a diode. Your doesn't. Is it safe? HP calculators use the standard RS-232 interface. So you don't need to plug any resistor or diode onto the connectors. Just the wires to route all the required pins from the calculator to the PC (as for serial devices like modems or mice). Q: Could you say the color-code of each wire (i.e., RED wire in pin #7, etc.)? After sliceing a cable, you'll find a lot of colored wires. As I have been told, the colour of the wires may vary, and may vary the pin each wire is connected to. You always need an ohmmeter to recognize each wire. Q: The cable doesn't work. And now? * Probably you have misunderstood the pinout numbering. Read carefully Section 2. Remember, pinout assignment in different between M and F connectors! * If you've checked the cable and performed the loopback test, and everything is working, it's probably a PC-side problem (software or hardware). See next question. Q: I've checked the cable, so I'm pretty sure it works; but I cannot use the HPComm software. What should I do? * You could ask to the HPComm support team. Before contacting them, please read the www.HPComm.org FAQs: http://www.hpcomm.org/faq.html . * Also, try using a simpler software (like Kermit) or the PC of a friend, in order to isolate software and hardware problems. Q: What is the preferred Project? As I'm told, the Project #1 using a mouse cable. Followed by #3. But if you already own the old HP48 PC-Link, the best choice is Project #5 (what I currently use). Q: Are you developing a Macintosh version of this page? Sorry, not at this time. 8. Related documents. * Description of some HP38, HP48 and HP49G cables & adapters: http://www.geocities.ws/hpcables/hpcables.htm * Connecting a modem to your HP48 or HP49G calculator: http://www.geocities.ws/hpcables/hp2modem.htm * HP49 Documentation files: http://www.hpcalc.org/hp49/docs/misc/ * The HP49G FAQ: http://www.hpcalc.org/hp49/docs/faq/ * The www.HPComm.org FAQs: http://www.hpcomm.org/faq.html 9. Obtaining the last version of this document. Primary address for this page is: http://www.geocities.ws/hpcables/cable49g.htm Secondary address: http://studenti.ing.unipi.it/~s172776/cable49g.htm PK-zipped version: (14 Kb) http://www.geocities.ws/hpcables/cable49g.zip Text-Only version: http://www.geocities.ws/hpcables/cable49g.txt 10. Contacting the author of this document. Feel free to contact me for any problem or question. My E-mail addresses are: * enrico@ieee.org * s172776@studenti.ing.unipi.it ------------------------- Written by E.Carta, enrico@ieee.org, Telecommunications Engineering Student at the University of Pisa (Italy). URL: http://www.geocities.ws/hpcables/cable49g.htm First version: Oct 2, 1999. Last Revised: Mar 01, 2000 - Version 1.20.