LC 580 on the internet. Possible with this modem?

[notcrazy_iminsane]

I finally got both my LC 575 and 580 up and running properly thanks to all of the help from you guys The LC 575 is currently up at my technical college for some major dusting. While I was up there, I found an old dial-up modem. Since I'm cursed with dial-up at home, I thought maybe I could hook this sucker up to my 580 before it gets a good dusting too.

It's a US Robotics 56k Faxmodem. The fact it's called a Fax modem throws me off a bit, but I'm determined to try. I started up my 580 with the modem attatched to the SCSI port, but the mac didn't start up all the way (it did the start up chime, then just went to the grey background with the curser and stayed there. I don't even think it did the happy mac).

I'm about to try again with the phone cables hooked up this time to see if that makes a difference. Is there some special process i need to go through for it to work? I've never worked with an old dial-up modem, and the only networking I've done was with Windows. So, any advice would be great

 

[notcrazy_iminsane]

I just tried plugging in the modem with the phone cables to the mac and it did the same thing as before. It doesn't matter if the modem is on or off, if I plug it into the SCSI port, it locks up. I can move the cursor around, but I can't click on anything. If I turn on the computer with the modem pluigged in, it stays on the grey screen, but as soon as I unplug it, it will happy mac and boot normally. xx(

 

[LCGuy]

1. The "Fax" part of "Fax Modem" makes no difference - in fact most modems are indeed fax modems - what that means is that as well as functioning as a modem, it also has fax functionality that allows you to send/receive faxes on your computer with the appropriate software.

2. Modems do not plug into the SCSI port - they plug into one of the serial ports. Obviously Macs don't use the same DB-9 or DB-25 connectors for serial that PCs do, they use a MiniDIN-8 connector instead. You'll need either a new cable with a MiniDIN-8 plug on one end, and whatever plug is suitable for the modem on the other end, or an adapter that goes from MiniDIN-8 to whatever plug on the cable that goes into the machine.

 

[CJ_Miller]

^ What LCGuy said.

The DB25 connector is probably for a PC parallel or serial port. For most purposes, they are compatible. RS232 (PCs) uses mostly a TX line (transmit) and RX (receive) for signals, and also +V and ground. The Mac 8-pin mini-DIN is RS422 which is differential serial over twisted pairs, so there is a +TX and -TX, with a +RX and -RX. I don't have links handy but if you do a google image search for RS232 and RS422 pinout, or connector, you should see some diagrams. The other control wires are not used for 99% of serial applications so you probably don't need to worry about those. IIRC I had best luck using the -TX and -RX on the serial adaptor I made last year for my Mac.

In use you will just need to find a suitable driver, and see what speed connection your LC can maintain. I recommend starting with 22k and going from there. If it can handle 33k, go up to 56k. If not, drop it down to the next slower one (22k?)

Good luck!

 

[notcrazy_iminsane]

Okay. It's the larger serial port that it's going to. The one with the SCSI icon above/below it (I forget which).

So it would be best to see if I can find another modem? I had a feeling it would go down to that. School will be open on Monday and I'll see if there's any other old retired modems. If I can't find any there then I'll wait for when I get some money coming in and buy one off of ebay. Thanks for the advice

 

[register]

Okay. It's the larger serial port that it's going to. The one with the SCSI icon above/below it (I forget which).

Beware, never call the port with the SCSI icon "serial port". The plugs might be compatible, but the electrical connection is quite different. That is what comrade CJ_Miller explained. Please go and find (or make) a modem cable that sports a mini 8 pin connector on the Mac's end (like the Mac printer or LocalTalk cable) and the appropriate connector to fit the modem on the modem's end. In fact the modem cable has to be connected to either the printer port or the modem port of your Mac. Similar cables might be available with different wiring, so look closely to what you dig up. Most likely you will just need the appropriate cable and some software, not another modem.

 

[IIfx]

Okay. It's the larger serial port that it's going to. The one with the SCSI icon above/below it (I forget which).

DO NOT PLUG IN NON-SCSI DEVICES INTO YOUR SCSI PORT.

Doing so can be FATAL to your macintosh. It is not a serial or parallel port, although they share the same connection. It could ruin the SCSI controller, which means no more hard disk bus. :O

(I was just a but worried, people understated what can happen.)

 

[notcrazy_iminsane]

Please go and find (or make) a modem cable that sports a mini 8 pin connector on the Mac's end (like the Mac printer or LocalTalk cable) and the appropriate connector to fit the modem on the modem's end

I'm going to be digging around to find a Mac-compatible modem. I know a couple people that are sitting on a surplus of computer parts who might have a modem that would work.

DO NOT PLUG IN NON-SCSI DEVICES INTO YOUR SCSI PORT.
Doing so can be FATAL to your macintosh. It is not a serial or parallel port, although they share the same connection. It could ruin the SCSI controller, which means no more hard disk bus. :O

(I was just a but worried, people understated what can happen.)

Noted. I think I'll ask anyone here before I even consider connecting anything to said port.

 

[register]

digging around to find a Mac-compatible modem

Just for clarification: usual external modems do not prefer a specific type of computer or operation system. As long as a modem is properly connected (using the appropriate cables plugged into the appropriate connectors), all you need is some software using a command set compatible to the modem, and you might reach to everything you can dial up to. If you have a small soldering iron available you might look for a Mac RS422 to Modem RS232 cable description and build the cable you need. Do not become discouraged, the first time I wanted such cable it took months until I found every piece of information I needed. Today we've got intarwebs and this forum Software for different purposes using modems is for example CoMa Mac (communication manager, including sophisticated answering machine features, customized versions might still be available directly from the developer), FirstClass (BBS software supporting dialup connections), ZTerm (Terminal, scriptable), Microphone (another Terminal software), FaxExpress Solo (Fax software with excellent self configuration capability), FaxSTF (another Fax software), FreePPP (connect to Internet, some additional software and configuration of your mac might be necessary).

P.S.: Most likely you will need a separate power supply for the modem. Again: look for matching specification (voltage, polarity, power rating) of the modem power input and the supply power output, even if the connectors seem to fit. Also the cable to connect the modem to a phone line must have the correct pinout. Despite it is possible to use a foolproof pinout, some devices use a different cable... Take care.

 

[MidnightCommando]

Noted. I think I'll ask anyone here before I even consider connecting anything to said port.

OR...

You could instead also note that the symbol above the SCSI DB-25 port (looks a bit like a sideways joystick) is present on ALL SCSI-compliant devices, so plugging in anything that doesn't have that little symbol on it somewhere is kinda dumb, and plugging in anything that DOES have that symbol will be safe, even if it doesn't really work.

Hope this helps.