Rs-232 serial modem cable

RS - cords transmit data between a modem and another device, such as a computer. Null modem cords connect two like devices, such as a computer to a computer. Parallel and serial printer cords connect a computer to a printer. Parallel cords transmit data faster than serial printer cords. Shielded cords have foil to prevent signal interference from nearby devices.

Use them in settings with low to moderate signal interference, such as labs, storage facilities, and offices. Double - shielded cords have braid and foil for better protection against signal interference than shielded cords.

However, the extra shielding adds diameter and reduces flexibility. Cords with reversible mounting hardware have removable thumb screws to enable a wider range of mounting options than other cords. Mount them to ports and adapters, as well as directly into panels. Transmit data between computers and other devices that have different USB sizes or styles. Originally, the RS standard was developed and used for teleprinter machines which could communicate with each other over phone lines. Each teleprinter would be physically connected to its modem via an RS connection and the modems could call each other to establish a remote connection between the teleprinters.

If a user wished to connect two teleprinters directly without modems null modem then they would crosslink the connections. The term null modem may also refer to the cable or adapter itself as well as the connection method. A null modem cable is a RS serial cable where the transmit and receive lines are crosslinked. In some cables there are also handshake lines crosslinked.

In many situations a straight-through serial cable is used, together with a null modem adapter. The adapter contains the necessary crosslinks between the signals. Below is a very common wiring diagram for a null modem cable to interconnect two DTEs e. The original application of a null modem was to connect two teleprinter terminals directly without using modems. As the RS standard was adopted by other types of equipment, designers needed to decide whether their devices would have DTE-like or DCE-like interfaces.

When an application required that two DTEs or two DCEs needed to communicate with each other, then a null modem was necessary. Null modems were commonly used for file transfer between computers, or remote operation.

Under the Microsoft Windowsoperating system, the direct cable connection can be used over a null modem connection. Both pieces of software allow the mapping of a hard disk on one computer as a network drive on the other computer. First of all, have to say purchasing this was a super smooth process, I even messaged them before it got shipped out to add a cable to my order. As for the device itself, I was able to get online with my Macintosh Plus. While the documentation that comes with it is enough to get you going, its definitely worth using AT?

What really saved me was the handle telnet option. With the modem handling telnet, I was able to access SDF pubilc access unix system and run lynx to get online. Plus, it shipped with an TheOldNet logo sticker! I had to setup an serial rs isa card, but when that was done the rest was easy using the provided short manual.

Shipment was perfect. It would be great if it could be made to act as a wifi adapater as well, so that we could do some web browsing as well. Still being able to connect to BBS'es is great! I highly recommend this for anyone looking to do anything I've described here!

Response from The Old Net Sept. I would love to see a video of your system with this modem in action! It all worked out though.

Found both as New old stock on Ebay. Using Zterm set to 8N1 seems to be the best for this particular machine. Response from The Old Net Aug. Rest assured I plan to offer multiple adapters as addon options and I will be offering them at a reasonable price! I have been testing out a couple different styles of adapter and seeing which suppliers can give me a decent price.

Ordering a box of cables is surprisingly expensive on shipping. It's a lot of bulk and weight. For everyone else looking for these options stay tuned, I'll likely have something in the coming weeks depending on shipping time. I haven't set it up for PPP with this modem yet. Was it easy?

Pavel March 17, Very good product. Dean March 12, Great product, bringing back memories!. This was a great purchase. I am now able to use my old software from the dialup days, software I thought I would probably never use again.

Very well designed and works exactly as advertised. Included documentation very clear and concise, and gets you up and running quickly. Definitely five stars! Eddie March 11, Just what I needed! I collect and restore vintage computers, and part of that includes re-living the online experience. The biggest factor for my purchase decision was the portability I can move this device from system to system with ease.

The serial port is located on the backside and has 9 pins. If you have different options e. An RS serial data cable is a simple and reliable tool. The newest modems use USB data cables. If you wish to build an environment where continuous operation is important, you should use an industrial GSM modem Figure 2 :.