iMac with external Zoom Modem

[Aarky]

My old iMac DV died, and I replaced it with a 20-inch Intel iMac. Wonderful machine, but it doesn't have a modem. I need to send faxes, so I dusted off my Zoom K56 Flex fax modem. This device has a 25-pin RS-232 serial connector, so I bought a USB-to-Serial converter ($7.50 on eBay). Unfortunately, the iMac doesn't recognize the fax modem. Any help in configuring would be appreciated.

Here are technical details for those that are interested.

System Profiler reports a Vendor-Specific USB device with the following properties:
Version: 2.00
Bus Power (mA): 500
Speed: Up to 12 Mb/sec
Product ID: 0x5523
Vendor ID: 0x4348

System Preferences : Print & Fax : Set Up Fax Modem
brings up the Fax List window but there are no fax devices listed.

Print: Fax PDF
brings up a dialog box stating "No Fax Selected", and there are no faxes to select from.

The modem has many lights on the front. The green MR (modem ready?) light is on, as are the red TR (terminal ready?) and CS (?) lights. If I remember correctly, this indicates that the modem is connected to the computer and ready for operation. During operation, the OH (off hook), CD (carrier detect), and FAX (fax mode) lights will come on, and the RD (read data) and TD (transmit data) lights will flicker. We are not getting this far, as no data is being sent to the (as yet unrecognized) modem.

The modem worked great for many years with my Centris; I retired it when I got the iMac with a built-in modem. All I need is the fax capability, as my Internet connection is by cable. I was hoping to save the $50 cost of the Apple USB modem (which also has many negative reviews on the Apple site).

I'm speculating that at the Unix level there is a configuration file for USB devices (let's call it .usbcfg) that associates the product ID with the type of device and its driver. If this is true, I could edit the .usbcfg file to tell OS X that 0x5523 is a fax modem and to use the appropriate Zoom modem script in the Library. Can anyone help in this area? Is there such a configuration file? If so, what is it's name and where is it located?

[mesamb1]

I hope this link helps. The intel macs are my favorite and the list of things that they can do is amazing. luckly for you the built in fax modem may do the trick :) I hope you are lucky enough to have one http://docs.info.apple.com/article.html?artnum=303266

[Aarky]

Unfortunately, the 20" iMac does not include a modem. Also, it does not recognize my external Zoom as a modem. Since Macs obviously can connect with external modems (witness the Apple USB modem), I think the problem is that the USB-to-serial converter I am using to connect to the Zoom (it has a RS-232 interface) is not recognized as a modem by OS X. At the Unix level that underlies OS X, there should be a way to tell the OS that the converter is really a modem. Just how to do that, I don't know and am hoping for some help on this forum.

[John A]

At the Unix level that underlies OS X, there should be a way to tell the OS that the converter is really a modem. Just how to do that, I don't know and am hoping for some help on this forum.

No, I think the problem is that you need drivers. Way hardware works with computers nowadays is:

External hardware (such as a Modem) -> Physically connected to computer -> Low level drivers talk to BIOS which talks to the hardware -> Operating system sees drivers talking to hardware, and "detects" a device.

The drivers are designed to be commmanded the same way, so that any software can tell the drivers the same command (such as "Scan me a document"), and the drivers are supposed to know how to do this.

This only adds to the complexity, because not only do you need drivers for this modem, you've also got a serial-to-USB adapter to worry about. In fact, it would probably be easier and you would get more performance on your modem by shelling out the $50 to get an Apple Modem.

[Aarky]

No, I think the problem is that you need drivers. Way hardware works with computers nowadays is:

External hardware (such as a Modem) -> Physically connected to computer -> Low level drivers talk to BIOS which talks to the hardware -> Operating system sees drivers talking to hardware, and "detects" a device.

My Google searches led me to the Apple developer help pages, and I must admit you are right. Not being a software developer, I didn't understand everything I read, but it seems that the OS USB software establishes a connection to the USB device then uses the (VendorID + ProductID) to find a driver. If not found, a generic USB connection is made, and that appears to be what actually is happening in my configuration.

This only adds to the complexity, because not only do you need drivers for this modem, you've also got a serial-to-USB adapter to worry about.

It shouldn't be hard to get drivers for this modem. In fact, the Library at the root level is full of modem scripts for a number of manufacturers, including Zoom. These are just text files, easily adaptable to my specific model, if necessary. The Zoom modem is "Hayes-compatible", using the standard AT command set. This means that the OS just has to be able to send ASCII characters out to the USB device, which it does do for the modems in the Library. The real question is how to tell the OS that the (VendorID + ProductID) provided by the adapter is a modem, and which script in the Library to use. This still sounds like an entry in a configuration table to me. Even if I wrote a driver from scratch, how would the OS know to use it?

This begs the question: Will a serial-to-USB adapter ever work for anything? No matter what the device on the other end is, the OS will see a (VendorID + ProductID) that identifies the adapter. The device will not have its own USB identifiers, because if it did, it would be a USB device and the adapter would not be needed.

In fact, it would probably be easier and you would get more performance on your modem by shelling out the $50 to get an Apple Modem.

Of course, you are right, but this has now become an intellectual exercise! I must solve this cryptex and find the holy grail!.

Seriously, performance is not an issue, as all I want to do is send an occasional fax. Probably most people don't have problems with the Apple USB modem, but many do, judging from the feedback on the Apple site.

[Junyah]

This might be a round about way to get the modem to work but here goes? but its free? Get a live Ubuntu Linux CD that works for the intel mac.
Stick the disk in and watch to see if it recognized the modem on boot up...Run the linux live but don't install it. If it works you can use the live linux cd only when you fax.

[goldnet]

My Google searches led me to the Apple developer help pages, and I must admit you are right. Not being a software developer, I didn't understand everything I read, but it seems that the OS USB software establishes a connection to the USB device then uses the (VendorID + ProductID) to find a driver. If not found, a generic USB connection is made, and that appears to be what actually is happening in my configuration.

The real question is how to tell the OS that the (VendorID + ProductID) provided by the adapter is a modem, and which script in the Library to use. This still sounds like an entry in a configuration table to me. Even if I wrote a driver from scratch, how would the OS know to use it?

This begs the question: Will a serial-to-USB adapter ever work for anything? No matter what the device on the other end is, the OS will see a (VendorID + ProductID) that identifies the adapter. The device will not have its own USB identifiers, because if it did, it would be a USB device and the adapter would not be needed.

I have a very similar problem using a USR Professional Message Modem (the kind that can store messages and faxes when a PC/Mac is turned off), which I don't wish to switch to an Apple modem which only works when the Mac is on, it also doesn't support voice as far as I know.

I occasionally need to send a fax and need, obviously, to be able to open a fax sent to the modem. I am also connected via a USB/Serial adapter. The adapter is recognised by the dial-up internet sub-system and works fine connecting via the modem with this. If I use the Fax Center software, it also recognises the modem and prints to it OK. OSX doesn't recognise the fax modem, however, and thus won't print to it directly. I see from modem manuafacturers support pages that older Mac OS had a printer/modem selection for modem connections and it seems to me that OSX isn't recognising the printer side of the connection (and thus won't print to a fax driver).

Can anyone offer any thought as to how to associate the serial adapter as a modem for print to fax purposes?

[paul110]

I had a really good read on this, very detail, and very useful information.
Thanks.