Finding FiberTalk: DuPont's AppleTalk-over-Fiber Hardware

[pl212]

Inspired by @cheesestraws 's improbable (but factual!) deep-dive into NeuNet, I wanted to ask for insights or experience with a much-discussed, and perhaps little-deployed, late 1980s AppleTalk physical network: Fiber Optics, from DuPont. I've chosen to call this "FiberTalk", on (slim) evidence that this was one of names used for an otherwise-ghostly product.

Our journey begins in early 1987, with the announcement of “DuPont Fiber Optic AppleTalk” in an article in Macworld:

DuPont Connector Systems has designed a fiber optic network to replace standard AppleTalk cabling. This new product overcomes AppleTalk’s 300-meter length limitation and will eventually allow users to send data 3 to 15 times faster.

DuPont’s fiber optic connection box, like the standard AppleTalk box it replaces, connects to the Mac’s printer or modem port. Two fiber optic lines link the Mac to the Apple- Talk network. The fiber optic cable extends the maximum length between nodes to 1/2 km, with no limit on total cable length. Although AppleTalk currently runs at 238.6K bits per second, DuPont is working on a version that transfers data at 600K bits per second using new Mac software and external clocking. Future versions of the product that connect to the SCSI port will allow AppleTalk to transfer data at 1/2 to 3 megabits per second.

DuPont also has announced a fiber optic wiring concentrator to simplify AppleTalk office installations. One concentrator connects up to eight Macs in a star arrangement similar to AT&T’s Starlan. Attaching two more concentrators expands the network further.

Ushijima, David. “DuPont Fiber Optic AppleTalk.” Macworld, January 1987.

OK, this sounds interesting -- kind of a bummer that the speed is the same, but neat that they're planning to get around that with the external clocking trick.

Five months later, rival magazine MacUser graces us with the first photo of the concentrator and associated equipment:



This pictures the concentrator (the large box), the wall plate (sort of sideways, in the middle) and the converter on the right. You can just make out a DIN-8 port on the left of this converter.

DuPont announced a fiber optic LAN (local area network) for AppleTalk. Developed for their own in-house use, the DuPont fiber optic LAN is modular, connecting each computer through an optical/electric signal converter. The fiber optics cabling allows users to add fiber optic links to an existing copper wiring network, or design one that is completely fiber optic.

There are several advantages to fiber optics, including increases in speed, distance and number of users. More than one hundred stations can be linked with individual nodes as far as 4900 feet apart. The system gives network designers the freedom to configure AppleTalk networks through walls, across floors and between buildings. It will be available at selected dealer outlets and directly from DuPont.

Wesley, Michael D. “Bumper Crop.” MacUser, May 1987.

Fiber-optic cabling was mainstream enough to warrant a mention in one of Apple's advertisements for AppleShare, in that same issue:


Apple Computer. “How to Get People Who Work Together to Work Together [Advertisement].” MacUser, May 1987.

Macworld gave us some hard prices a few months later:

El duPont, Inc. Fiber Optic LAN for AppleTalk $700.00
Converter box; wall plates; fiber-optic cabling; concentrator for star topology. Req. AppleTalk. $700-$1100 per node.

Hecht, Jeff. “Macworld Business Buyer’s Guide 1987-1988: Communications.” Macworld, November 1987.

Hm, that sounds pricey... but apparently the whole setup had some status, as mail-order firms who advertised in the back of magazines were eager to promote their advanced networking:


The Saving Zone. “The Saving Zone [Advertisement].” MacUser, November 1987.

The San Francisco Macworld Expo apparently provided some real-world exposure to the product show show-goers:

One area of intense competition: providing alternatives to Apple’s AppleTalk cabling. Farallon started this off some time ago with PhoneNet; now there are offerings from DuPont, Northern Telecom, Nuvotech, and TriMar USA.

Borrell, Jerry. “What’s in a Show? New Products Aplenty.” Macworld, April 1988.

Rival MacUser elaborated on one specific use for Dupont's fiber-optics products, with their immunity to electric eavesdropping:

Another heavy-duty useful product: DuPont introduced Mac II Fiber Optics Communications Card that makes it easy to adapt a Mac II to Tempest environments in which, generally for security reasons, all electrical components must be shielded to prevent electromagnetic emissions).

Zilber, Jon. “It’s a Mac, Mac, Mac World.” MacUser, April 1988.

I had thought another use case for fiber would be very long runs, but Macworld noted a 1,000 ft limitation:

Another network medium, fiber optics, also allows wider bandwidth. DuPont offers converters, which interface AppleTalk to fiber-optic cable, and a central controller for forming small networks. The fiber-optic bandwidth is even wider then Ethernet’s and thus can carry more network traffic. Network lengths, however, are limited to 1000 feet. Fiber optics also offers the advantage of data security, since it’s almost impossible to tap the cables. Unfortunately, fiber-optic cable is expensive and difficult to install.

You can configure a star topology as active or passive. Active stars use a controller, such as DuPont’s fiber-optic Concentrator, or a special isolator/repeater, such as Farallon’s StarController, in the hub of the star.

Kosiur, David R. “Expanding the Conversation.” Macworld, May 1988.

Kosiur's article also reënforced the notion of astronomical costs, with the 8-port concentrator listing for $950 and an adaptor for $250. That's nearly $400 per drop, in 1980s money... for LocalTalk speeds.

The photographic team at Macworld does do us the favor of one of their artistically-arranged product shots, cropped here to show just the DuPoint transceiver amidst other more quotidian Farallon gear:



MacWEEK provided some welcome technical details on DuPont's system:

Optical links are another wiring possibility. Nothing in the AppleTalk architecture requires the connections to be electrical, and an optical approach has certain advantages, according to Warren Umstead, market development manager for Du Pont Company Fiber of Myrtle Beach, S.C. Optical cables are immune to electrical noise (EMI and RFI); are virtually impossible to tap; and don't have problems with grounding, shock or signal radiation. A single link on the fiber cable can be as long as 1.5 kilometers. Du Pont's Fiber Optic AppleTalk product line is built around two sizes of optical fibers, a converter box and an 8-port concentrator. All components may be mixed freely with LocalTalk and compatible systems at the plug interfaces.

Each fiber-optic cable consists of two fibers (each carrying signals in one direction) with a plastic coating. The standard grade uses a 200-micron diameter fiber, which, in theory, can carry signals up to 10 MHz. The smaller, more precise 62.5-micron diameter fiber can carry 200 MHz. The optical pulses are generated by an LED in the converters or concentrators and received by special photodiodes. The large bandwidth of either fiber may be overkill for low-speed AppleTalk, admits Umstead, but once the fiber is in place it would only take an upgrade of the converters to speed up the network. Either cable can be used with medium-speed networks such as Ethernet, and the higher-speed cable also could be used for forthcoming high-speed standard networks such as the Fiber Distributed Data Interchange (FDDI) proposed by The American National Standards Institute.

Fiber-optic systems generally are priced individually, but Umstead said a typical price is a few hundred dollars per node.

Rosenthal, Steve. “Sorting out the Cables.” MacWEEK, July 12, 1988.

Don Crabb talked up the system, although it doesn't sound like he used it or saw it deployed at UChicago:

And if you really want to go high tech, Du Pont will sell you a system of fiber-optic cables and solid state lasers that run AppleTalk.

Crabb, Don. “Getting Started with AppleTalk LAN.” MacWEEK, January 3, 1989.

By mid 1989, it appeared that the emergence of the EtherTalk logical layer had enabled a much faster use case for the physical transport:

In fact, DuPont 's fiber-optic cabling operates at the same speed as Apple's LocalTalk wire when used with the Mac's built-in LocalTalk circuitry, and at Ethernet speeds when used with an add-on Ethernet card. [...] Fiber-optic cabling extends this even farther to 4,900 feet between nodes and can be used as a backbone for connecting work groups located some distance apart. It's impervious to electromagnetic interference and very difficult to wiretap - an important consideration for high-security installation. As you might expect, you pay a price for these benefits: DuPont's fiber-optic cabling for the Mac cost a minimum of $300 to 5600 per node.

Rizzo, John. “Signals and Servers.” MacUser, May 1989

In fact, it seems to have also been deployed underneath the Token Ring protocol. The faster 16 Mbit/s standard was deployed in 1988, so it's theoretically possible a TokenTalk-equipped Mac running DuPont fiber might have exceeded Ethernet speeds. (Neither likely or probable however!)

Other companies supporting the Macintosh token ring include Du Pont Electronics, with TokenTalk-compatible fiber-optic network hardware...

Battelle, John. “Third Parties Join the Connectivity Products Parade.” MacWEEK, July 11, 1989.

A 1989 article in Macworld hints at a re-branding towards "FiberTalk" and a price of $595 -- almost certainly for a NuBus card. [Meng, Britt. “New Life for the NuBus.” Macworld, July 1989.]

And the last significant mention comes from June 1990, where a further-renamed "LAN One Universal Concentrator" listed for $220 per node for 34 nodes. (This would be quite a large device and expensive device! ) [MacUser Labs. “Guide to Network Products.” MacUser, June 1990].

So! Did anyone ever see this used, or participate in its deployment? Has anyone ever run across this on eBay? Was it all vaporware? One enquiring mind wants to know...

 

[Mk.558]

Fascinating dive on your part. Thanks for the quotes!

Have you looked at FDDITalk?

 

[NJRoadfan]

The level 2 protocol was likely FDDI (100Mbit) on these early fiber networks. Later on it was easier to just run Ethernet frames over fiber when 100Base-FX became available. Remember in the late 80s, Ethernet was not a sure bet at becoming the standard for the physical layer. Token Ring and FDDI were faster and had established media interfaces. The real game changer was the availability of dirt cheap 10BaseT UTP, although 10Base2 ThinNet coax made significant inroads in smaller offices.

 

[eharmon]

Neat! 1,000 feet really isn't bad. Beats thinnet and 10Base-T, so it's not too shabby really, if your primary need is long runs (connecting campus buildings and such). Seems pretty niche, but it definitely would have found it's uses in large deployments.

Never understood why I needed to be able to print something two buildings away at school, but damn if every university didn't think that was an important feature of the network. (I suppose in the early days when there were only a few nice printers it mattered, but that only lasted so long).

 

[cheesestraws]

This is great, thankyou!

What really tickles me about this is that I was going to see if I could build something like this as a joke (using S/PDIF optics); the fact that someone actually built it as a product is kind of wonderful.

mail-order firms who advertised in the back of magazines were eager to promote their advanced networking

I wonder how much of a discount they got on their equipment bill for putting that in the ads ;-)

I had thought another use case for fiber would be very long runs, but Macworld noted a 1,000 ft limitation:

I wonder if this is an indication that they're using LEDs rather than lasers here. (Oh, never mind, on more careful reading, MacWEEK says this directly):

The optical pulses are generated by an LED in the converters or concentrators and received by special photodiodes

Presumably this also implies the use of multi-mode fibre (edit: yes, see note below on fibre diameter which is two orders of magnitude too big for SM). So that'll account for the range limitation then.

The level 2 protocol was likely FDDI (100Mbit) on these early fiber networks.

It's possible, but don't forget that you can also run {S/H}DLC directly over fibre pretty easily; and although absence of evidence is not evidence of absence, note also that nobody above says that if you upgrade to the newer faster stuff, you can use that on the same link. So the LocalTalk speed version might well have just been SDLC, to keep costs down, going up to FDDI-lite when you upgraded the speed.

But also note that the physical layer certainly isn't up to scratch for FDDI. MacWEEK sez:

The standard grade uses a 200-micron diameter fiber, which, in theory, can carry signals up to 10 MHz. The smaller, more precise 62.5-micron diameter fiber can carry 200 MHz.

FDDI-type MM fibre is 62.5 µm, so probably the smaller fibre mentioned here. 200 µm is huge. So they're certainly doing something funky here. I'd love to take some to bits to look at it.

Feels like the profit marging on these ought to have been quite high...

 

[cy384]

Neat find! It will be neat to see if anyone ever turns up any of the hardware for this.

This is tangential but an amusing thought, I bet it wouldn't be impossible to recreate this using modern (super cheap) 1G SFP modules like so https://blog.benjojo.co.uk/post/sfp-experiment-ultra-long-range-toslink