Low End Mac Reviews

Review: Griffin gPort

Andrew W. Hill - 2001.03.28, updated 2001.03.31

One day I was cruising eBay when a Griffin gPort jumped out at me. It was something I was somewhat familiar with, being one of those things I had thought of buying around the same time I bought my computer, but I never got around to.

The Griffin gPort is a device that adds a standard Macintosh serial port (RS-422) to the Blue G3. While many Yosemite designmanufacturers made PCI cards to do this, Griffin opted to use the internal modem slot instead. The only downside is that the test computer slowed down significantly while printing. This didn't happen when using either a hardware bridge or a Mac IIci connected to the G3 via ethernet and the printer by LocalTalk. However, it's not unusual at all for a machine being used as a LocalTalk bridge to slow down significantly while the document spools across the interfaces.

One of the major issues with the earlier serial port PCI cards was that they did not support LocalTalk, so while you could use it to attach an older serial device or printer, it couldn't be used to connect to a LocalTalk network. For many people this wasn't a major issue, but as I work with a lot of older Macs, I like to have a way to transfer information easily between my computers.

The other problem with using PCI solutions is the small number of PCI slots. Macs have always been a little PCI-slot hungry, and the Blue G3 is no exception. For many people that fill their PCI slots with SCSI cards, multiple display cards, or professional sound cards, there just isn't enough room. The downside, obviously, is that you cannot have an internal modem. As I bought my Blue G3 without the modem, this wasn't a problem, but it will definitely be a consideration for some people.

I managed to get my gPort at about half the retail price on eBay. It unexpectedly turned out to be the "Professional" version, which included a nice cute three-port MiniDIN-8 switch. The gPort retails for around $50 for the standard edition, with the Professional Edition selling for an additional $10. The only difference between the standard and professional models is the three-port switch, which may or may not be of use to you. The switch is very small, which is both good and bad. Despite the length of the cable, it is sometimes hard to reach the switch. My Blue G3, Chtzrik, sits under my desk, and this makes it impossible to reach the switch. As I use a standard size 2-port MiniDIN-8 switch anyway, I just daisy chain Griffin's into my old clunky one. To this day I've never had all five ports filled at the same time, but I have come close.

Installation was remarkably easy, partially thanks to the decent manual that was included. By decent I mean by today's standards - it still wouldn't have been enough to make a double period's worth of spit balls in high school (estimation only). In any case, it was useful.

There were only three parts to the hardware - a board that fit into a slot on the logic board, a board that screwed onto the back of the case with the port, and a cable to join the two. It was somewhat reminiscent of installing an ethernet card into an SE, only much easier. (If you manage to break a CRT installing a Griffin gPort you may have done something wrong.) After closing up the case, I installed the included software. It is available for free download from their website, which was what I did. Being on a college LAN with a backbone Internet connection, I tend to download drivers to ensure I get the latest version. In this case, the version I downloaded was the same as the version included in the box. If I thought installing the hardware was easy, installing the software was almost a joke. Four or five mouse clicks (and a license agreement) later, the computer restarted and my gPort was ready to try out.

The first thing I did was to try to establish a LocalTalk connection with my pet Macintosh IIci that perpetually occupies a few precious square feet on my desk. Initially I set up the IIci as the file server and went into the Chtzrik's AppleTalk control panel. A new option greeted me: Modem Port. Makes sense - it uses modem slot, has a little telephone icon next to the port, and has the same plug as a traditional Macintosh modem port. I closed that window (yes, I would like to save my changes), opened the Chooser, and my IIci showed up in the AppleTalk window. The second test was with a printer - my Mom's Hewlett-Packard 855c. After downloading and installing the drivers, I once again opened the Chooser. Under the "DJ 800 series" header was an icon identical to the modem/printer port of many PowerBooks. In another printer driver it was called the Printer/Modem Port. Printing worked great, no difficulties beyond any that one would experience on a beige Power Mac.

The next concern was speed. I had no reason to suspect that the port would be any slower than the high-speed serial of older, beiger Macs (230.4 kbps). However, as the modem only needs 56 kbps throughput, the slot might not have been capable of providing as much bandwidth. Conversely, it might have been capable of far higher speeds.

In order to get an idea of its speed, I transferred a small file between Chtzrik and my IIci, timing it with a watch. This was slightly faster than the same transfer between Mom's 7100 and the IIci, which I attribute to three times the RAM and the Ultra2Wide hard disk. I really would like to get a proper benchmarking utility to test this with (please email suggestions - Norton's doesn't count). Miscellaneous file transfers between Chtzrik and a 6400 seemed no faster than between the 7100 and the 6400. All this satisfies is that the gPort is capable of maintaining the same throughput as older machines.

I would be interested to clock the speed between two gPort-enabled Blue G3s to see if it is capable of speeds higher than the standard Macintosh serial port. It is unlikely that it is significantly faster, as there would be little practical use to such a design - the only way the extra speed could be used would be between two Blue G3s, which already have 100 Mbps Ethernet built in.

As one must sacrifice the internal modem of the Blue G3 in order to add the Griffin gPort, I explored the possibility of connecting an external serial modem to the port. I used the Global Village Teleport Platinum and the Global Village Teleport 33.6k. On both Chtzrik and the 7100, they connected at 28.8 kbps and 31.2 kbps, respectively. According to the Cnet bandwidth meter, the bandwidth was identical for both machines on the 33.6 modem, while the 7100 measured as faster on the Platinum. It wasn't a significant difference, and I'm attributing that to random Net congestion.

In a real world download of a 600 MB file, the speeds were very similar, Chtzrik being ahead by about 2% - once again probably due to the faster disks or the larger amount of RAM.

All in all, the addition of the Griffin gPort to my Blue G3 was the easiest modification I have made so far. I've had less trouble with the gPort than I have with additional hard drives, PCI cards, and even RAM. It has been a very dependable and useful addition to my computer, with the only disadvantage being the need to use an external modem for remote access.

One should note, however, that one can't use the gPort for a LocalTalk bridge. This is because, as Apple states, that LocalTalk Bridge is only partially compatible with OS 8.6 and not at all compatible with OS 9. I attempted to run LocalTalk Bridge under MacOS 9.0.4 with results varying from nothing to a system crash.

As far as I am aware there are not yet drivers for the gPort under OS X, so that could be a consideration if you plan on using OS X.

UPDATE: Paul Griffin of Griffin Technology, Inc. emailed me to point out some software that Griffin had released to allow blue G3s to use LocalTalk Bridge. In my tests, I was unable to make the gPort work with LocalTalk bridge. I attributed this to Apple's claims that it is not fully compatible with Mac OS 8.6 and incompatible with OS 9. After doing some tests on a beige G3, I found that LocalTalk Bridge 2.1 worked fine under Mac OS 9.1. Griffin's web page notes that the reason it does not work with Apple's LocalTalk Bridge is because the gPort reports itself as a modem port, not a printer port (which LocalTalk Bridge requires). The software from Griffin patches Apple's LocalTalk Bridge to recognize the modem port for the bridge. So far I have found it stable and reliable.

As for OS X compatibility, Paul Griffin has the following to say: "We are working on a OS X driver that would allow some OS 9 applications and drivers to work when run in Classic mode. Any existing OS X serial drivers should already work. There are not a lot of these yet, but we have tested modems and they worked fine."

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