I-Appliance BBS The Official Source for Internet Appliance Upgrades and Mods BBS Main List | Sign In | Sign Up | Search | Help | Linux-Hacker.net Reply to Thread | Printer |

Home / I-Opener Areas / I-Opener Technical Stuff Converting IO Modem to an External Modem

Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email I was wondering about the feasability of removing the IO modem and placing it in a small project box (or shoebox, if you want to relive some old memories). A regular DB9 or DB25 connector could be hooked up to the serial connector on the modem, and a small power supply as well. Would there be any issues with voltage levels on the serial lines? What DC voltage/amperage does the modem use? How could I rig up RX/TX/etc LED's to the modem board for diagnostics? I'm sure I can find the pinouts for the port somewhere on this board, it's just the actual physical connections that I'm worried about, as this is the only modem that I've got my hands on, and I'll be moving back home from college soon, so no more college T3 line... 04-21-2001 17:00:38

RE:Converting IO Modem to an External Modem (modified 0 times) mp3boombox Profile | Email I'v already created an external modem out of one of the io modem's If you would like i can email you the basic info on how to create an external modem out of one. VERY easy some parts from RS and IF you have one on hand an old 28.8 or less USR external modem. you cann even get the lights working like a regular modem.farly easy. the audio out to the line in ona sound card thats easy enuff. the connector is a 16pin connector. that means (10[9]) pins go to the SERIAL port 2 pins go to the + and - power, and 2 wires go to the phone line. the power is nothign morethen 5v 500ma or you could do like i did and get one of them small stupid black boxes from rat shack and build a box out of one of them. to behonist I'v not shure which modem works better?? I'v got an external USR 56k modem. and I'v got one of these IO modem's made external. but as to which is faster or better ?? i think there neck in neck but the IO one seems to be a slight SLIGHT bit faster by maby half a kb on average. 04-21-2001 18:58:02

RE:Converting IO Modem to an External Modem (modified 0 times) BadFlash Profile | Email Just a little curious. The IO modem seems to work pretty well. Why would you want to use an external modem? You can also get some pretty nice USB modems if you really want to use something else. 04-21-2001 19:46:36

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email mp3boombox: That'd be great, my email is snewby @ nmu . edu I was thinking of the black project boxes from RS myself, and using a pack of their 'assorted LEDs' for the status LEDs. I've pretty much got everything else I would need. BadFlash: I want to convert it so that my poor IO doesn't have to worry about IP routing/firewalling/masquerading as well as Xwindows. :) I'm still running with the Rise 266 at 200MHz, and it's not the fastest box on the block. I'd much rather let my 500MHz server play with the task of PPP and IP routing, as well as firewalling and such. But that means I need to move the modem, or buy one. And being a broke college student, I'd rather buy $10 of parts from RS than a new $100 modem. Anyway, thanks for the help guys! I'll be sure to post when I get it up and running. 04-21-2001 20:18:13

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email Ok, found the pinouts for the Modem (or rather, the connector on the MB for the modem, same diff) and it seems easy to wire up. Now I just need to find a way to hook up status LED's to the modem. I've done enough electronics to see that transistors triggered on the serial rx/tx lines would give me transmit/recieve LED's for the modem, a transistor on the RING line for a LED to indicate incoming calls, and a power LED would be easy too. After that I'm stumped though. Audio should be easy enough, although I don't know that I want that feature (if it even works). Carrier Detect, Off Hook, etc. would be nice, but not neccesary if they require much beyond basic soldering skills. 04-22-2001 09:48:28

RE:Converting IO Modem to an External Modem (modified 0 times) friar Profile Hey, this is probably one of those totally useless ideas but... Wouldn't it be cool to have modem status lights, even if your modem was internal? Why don't 'they' make computers like this? Is it feasible? One more idea, related to the above -- mebbe someone can hack us up a TSR that would use the IO's lights, one for Xmit, one for receive? Probably would be done in C, but I don't know much more than that. 04-22-2001 11:35:21

RE:Converting IO Modem to an External Modem (modified 0 times) BigDog Profile | Email Silly question, the interface on the i-Opener's Actiontek modem is TTL not RS232.... Making the modem external would only permit your to use it with the i-Opener and it would need to be very close since the signal is TTl (a 6' modem cable most likely wouldn't work) or some other type of computer with only a TTL com port. So even if you did make it external and you could only use it with the i-Opener, Why wouldn't you just leave it in the i-Opener case ?? Unless you could add the RS232 MAX235 mod to it to convert the TTL back to standard RS232, but again, why? The external Actiontec USB modem only cost $68 http://www.accessmicro.com/productinfo.php3?ProductId=A1058C44 and standard Conextant external modem for $19.81 http://www.accessmicro.com/productinfo.php3?ProductId=C2263N79 Am I being a little too practacal here ? 04-22-2001 13:12:45

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email The idea isn't to make the modem an external modem for the IO, it is to make it an external modem for a standard Desktop PC with a serial port. According to mp3boombox, this is fairly simple, but I haven't seen any information beyond pinouts as of yet. As for changing the TTL +/-5V to RS232 +/-12V (if memory serves), it shouldn't be much more complicated than a 12V supply, and a few PNP and NPN transistors. I might even be able to use a voltage-doubling circuit to pull a 5V PS up to 10V for the RS232 voltages. I still think this would cost less in raw parts than a $20 USB modem (I use Linux on all my boxes, IO included, and have sacrificed all my MS licenses to the penguin gods) that most likely won't work with my computer. Heck, I'd be happy if I could use a connector from an old desktop power 'Y' adaptor to pull 5V/12V from the desktop itself via a PS cable. This would defeat the purpose of external, but It'd be a lot closer, and better shielded too (metal desktop case). But anyway, the main purpose is to get the IO out of the routing/firewalling/masquerading loop in my network, so that it can focus all 200MHz on mp3's and stuff.. 04-22-2001 14:19:24

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email I just remembered, RS232 states an operating voltage of +/-(5V to 12V), so TTL (which is 5V) should be fine. Even if the TTL is 'split' to +/-2.5V, i could still use the 5V PS to juice it up a little. Even the MAX235 hack doesn't do 12V RS232, it settles for 5V. 04-22-2001 14:52:49

RE:Converting IO Modem to an External Modem (modified 0 times) r_fl_z Profile | Email While the MAX235 uses a single +5v supply, it generates a +/-10v (unloaded) bipolar logic level, which complies with the RS-232 'standard'. 04-22-2001 17:12:11

RE:Converting IO Modem to an External Modem (modified 0 times) mp3boombox Profile | Email well to make a long story short, yes the modem uses ttl data. This will limate you to how far you can go with the modem. VERY LIMATED, to correct this the use of a max chip will be in need to beef up the signal and run it at rs232 levels. I could go into detial but it's late and i realy dont want to TYPE a novel. 04-22-2001 18:57:24

RE:Converting IO Modem to an External Modem (modified 0 times) hayfever Profile | Email Reading through the posts, it seems that the reason deornoth wants to make his modem external is because he, like many others of us, don't have tons of cash laying around, and he thought he could move this modem external easily. Since this can't be done without parts, some expensive, I did a search on pricewatch. There is a 56k internal pci modem for $5 ($12s/h), and an external 56k modem for $32 ($4-6.50s/h). The max235cpg chips are $10 apiece, so if you have any internal slots, you're already saving money. 04-23-2001 08:23:20

RE:Converting IO Modem to an External Modem (modified 0 times) Programmer Profile There is no need for a max232 type device, even when connecting to a standard serial port. just keep the wires short enough to prevent noise and you'll be fine. how short that is I'm not sure, but 3ft should be all right. so.. find 5V somewhere to power the circuit, connect the wires and be on your way. 04-23-2001 09:26:09

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email hayfever: Right on the money with the reason. But a $20 PCI modem is most likely, well, a piece of crap. I've worked at an ISP before, and have seen quite a few of the newer 'Winmodems' out there. To tell you the truth, I would NEVER EVER buy one of these, let alone even want to recieve one as a gift. Ok, $32+s/h for an external? Is that USB? If it's a serial modem, then that sets my goal for modifying the IO's modem to under $30. That and, why would I just buy one, when modding one is much more fun? So far it looks like a DB9 connector (which I have) and wires (on the DB9), some LED's (which I have), some transistors (which I have), a power brick (might need to buy, prolly have), a power jack for the modem (hack out of another dead device, or buy), a phone jack (prolly already have), and a little black box for it all (a few dollars at RS). Heh... looks like I'm gonna beat my $30 limit/goal. 04-23-2001 10:23:23

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email I've taken a look at Prefect's schematics for the MAX205CPG or MAX235CPG chip, and it doesn't look like it would be very difficult at all. Just order free samples of each, and you've got 4 chips to work with. Solder everything to a 24pin socket, and away you go! I'm just not too sure on my supply of 1uF caps (if I have any, or can get any), anyone know of any viable alternative values (or range)? Then it wouldn't matter on the cable length, and a standard 6' modem cable would work perfect. Heh, an external, linux-friendly modem for the cost of an encloseure and some time with a soldering iron. I like the sound of that. 04-24-2001 14:31:29

RE:Converting IO Modem to an External Modem (modified 0 times) r_fl_z Profile | Email CyberRebate almost always has a $120 PCI 56K modem that is free after rebate...if that interests you. 04-24-2001 16:40:16

RE:Converting IO Modem to an External Modem (modified 0 times) ttn1 Profile | Email The capacitor is just a filter for the power input. Low pass filter to give cleaner DC power. If you have a good clean supply, it shouldn't even be an issue. I think you could use anything from .1 microfarad to 10 microfarad and not have an issue. It just depenmds on the designer of the circuit as to the value. Some people use .1 some use 1. For low noise circuits I use 2 capacitors, a large and a small value. Probably more info than you want. ttn2 04-24-2001 17:53:24

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email ttn1: Thanks, that's what I thought it was for, but I thought I would check anyway. I've ordered free samples of the MAX205CPG and the MAX235CPG chips, so hopefully I'll have a modem that has a better RS-232 compliance than +/-5V. I've also seen a number of posts here that seem to be to the effect of 'Why bother modding the IO's modem, when you can just buy one?' ...ummm... Doesn't that defy the purpose of this board? In my searches of the board, looking for information on the modem, I've run across only one or two other posts involving removing the IO's modem and using it as a standard external modem. The same response was given there, 'Why remove it? You can just buy one for $xx.xx at suchandsuch.com!' Anyway... I think I'm done for now, and will keep working on figuring out how to make the modem work right. One last bit though, does anyone know right off where I could find the info for the pinouts on the female DB-9 connector that goes on the modem? I know enough to cross the RX/TX lines, so that when the computer tx's, the modem, rx's, and vice versa, but the rest? Thanks for the help so far! 04-24-2001 19:32:34

RE:Converting IO Modem to an External Modem (modified 0 times) brian Profile | Email You shouldn't have to reverse the RX and TX wires on the connector. The only time you need to reverse the wires is when you are connecting two DTE (computers) devices together. The cable that you use should be a straight through cable. The "twisting" should be done in your black box. The TX of the modem should go to the RX of the PC... If you are going off the pinout from the IO then this translation is already done for you. If you need to know which pin of the 9 pin connector is which, check out http://mtu.net/~bjcouche/connecto.htm and refer to the 9 to 25 pin converter. The signal types are in refeance to the PC. If you look closely at a connector (yours, not on my web page :)) all of the pins should be numbered. Brian 04-25-2001 17:07:57

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email brian: So what you are saying is that the TX line from the computer hooks to the TX line on the modem? As in, all the lines on the modem are 'recieving end' lines? Last I was aware, the TX line from the computer had to hook to the RX line from the modem, and the RX from the computer to the TX on the modem. That way, when the computer sends a byte, the modem gets a byte, and so on. The only question I had was about the RTS/CTS/etc. lines (5V and GND are easy enough tho). Hooking up the lines is no problem, it's just WHERE to hook them. I'd be doing all wiring between the female DB-9 and the MAX235 chip, so crossing wires is easy (and so I can use a standard 'modem' serial cable, or 'extension' serial cable, NOT a crossover cable). Wow, and I thought that I had it all figured out. Ahhwell... here we go again! 04-25-2001 18:39:40

RE:Converting IO Modem to an External Modem (modified 0 times) deornoth Profile | Email brian: Ok, checked the site you linked, and found the Null Modem pinouts. It looks straightforward enough. So I'd just be doing all this crossing between the DB-9 and the MAX235? If so, that should be easy. 04-25-2001 18:56:17

Reply to Thread | Printer | All times are PST Powered by UltraBoard v1.62

I-Appliance BBS General - NEWS, Breaking NEWS - linux-hacker.net BBS on CD Questions - User Groups in Your Town - E-Bay, Yahoo Auction LINKS ONLY (MODERATED) - Jokes & Humor - usdtv box I-Opener Areas - I-Opener General Posts - I-Opener Technical Stuff - I-Opener Technical Info Reference (MODERATED) WebSurfer Areas - WebSurfer General Posts - WebSurfer Technical Stuff - WebSurfer Technical Info Reference (MODERATED) Other I-Appliances - Virgin Webplayer - WebPal - MailStation - 3Com Audrey - ThinkNIC / Oracle NIC - Gateway/AOL Connected Touch Pad - Philips/AOL-TV - ACER NT-150 STB - MSN Companion - Compaq IA - Emachines IA - IBM NetVista IA - Intel dot.station - MSNTV2 Network Computers - Fujitsu-Siemens Scovery Linux Net Computers - GallantWeb Server Consoles - Dreamcast - xbox hacking Web Pads - Epods One General Post - Panasonic CF-01 - Fujitsu Stylistic 1200 - Cybiko Thin Clients - Thin Clients DigitalVideoRecorders - DTV Recorders, Replay, TiVo, Etc... - Tivo Hacks Linux - Midori Linux General Board - ITX MotherBoards Single Board Computers - Earth Computers mARMalade Elite Member Area MISC Areas - The Swap Meet WE TAKE NO RESPONSIBILITY FOR ANY TRANSACTION HERE AND NO COMMERCIAL POST PERIOD !!! - Wireless Net - Cameras - Robotics - Routers/Gateways - Mattel JuiceBox