eharmon

Contents

Note: This is a work in progress.

Background

What are MediaNet cards?

MediaNet was designed by Sonic Solutions as a part of their audio ecosystem offerings, which had a particularly strong focus on professional CD Mastering. This process requires significant amounts of digital audio being processed in real time, which was a significant challenge in the 1990s. With multiple audio engineers working on content it was impractical to duplicate all the data on each workstation, and with the volume of content and need for performance, existing network solutions couldn’t handle the task.

As a result, Sonic introduced MediaNet, a complete hardware and software system up to the task:

Together this allowed one Mac to host files on SCSI drives and another to mount them, but with significantly improved speed and expandability. They were available for both NuBus and PCI Mac systems.

Are they useful?

Today? No. Even for retro computing? Unfortunately, still no.

For file sharing?

FDDI and CDDI hardware is rare and hard to find, and you probably won’t end up with anything to connect this to.

As a local SCSI drive?

The 53C90 on board may be faster than your onboard SCSI bus if you have a Mac II, but you can’t use it as a boot drive and it limits EtherTalk usage for AppleShare. If you really badly want another SCSI bus, it’ll do, but it’s limitations are significant.

What if it’s only $3?

That’s what I paid for mine, and I’d say it was a fair price.

What the heck is FDDI/CDDI?

FDDI was a competitor to Ethernet in the 1990s, first using fiber, but eventually supporting twisted-pair copper as well via CDDI. Like fiber versus copper Ethernet, these are generally interchangeable despite having unique names, provided you have the requisite media transcievers for each type.

Crucially, FDDI and CDDI were faster than Ethernet for a period in the early to mid-90s. While Ethernet was still limited to 10Mbps, FDDI/CDDI could provide 100Mbps, even over copper. Over time this advantage disppeared as faster Ethernet networks arrived and FDDI faded into obscurity.

Confusingly, CDDI is standardized to use UTP cabling, as such the physical interconnects for CDDI and Ethernet are the same (Cat 3+ cabling), though they are not compatible at a link layer and networks cannot be mixed.

This usage of UTP cabling meant this could be a cheap way to build very fast file sharing networks, perfect for heavy media applications, and thus Sonic chose this as the basis for the original MediaNet.

The Lost Manual

So far I haven’t turned up a full manual for MediaNet cards, so this section serves as my reverse-engineered discoveries.

I’ve specifically tested this information with a Sonic Solutions MediaNet, Rev G3 with the SERVER 1.7⍟ ROM and CDDI media interface, produced in 1994.

What this covers

This documentation covers basic setup of the card and local mounting of drives. I only have a single card and no CDDI concentrator so I’ve been unable to test FDDI/CDDI functionality.

Hardware Specifications

This card is powerful and expensive for the era. It has a proper ‘030 on board running with its own operating system managing two SCSI buses and the FDDI interface, with support for DMA to the host for fast local disk transfers.

It contains both a read-only EEPROM for initializing the card and a writeable Flash chip which contains the support code for interfacing with MediaNet which is dynamically updated by the MediaNet software over NuBus.The Flash also contains the FGPA bitstreams.

The card’s ROM comes in Server and Client flavors. It’s unclear to me what the difference is.

Software Specifications

MediaNet support consists of two parts: FDDITalk support for Mac OS and the MediaNet Software.

FDDITalk

FDDITalk is rare. The normal Network Software Installers only provide EtherTalk (Ethernet) and TokenTalk (Token Ring) support, so it seems this was generally vendor licensed and provided. Looking at the version provided by MediaNet it consists of:

MediaNet

Card I/O

Card Setup

  1. Install 4MiB, 16MiB, or 64MiB of 60ns SIMMs on the card
    • Must fill all slots (ie 4x1MiB for 4MiB)
    • Some documentation insists it must be 60ns, but I’ve been able to stretch it
    • The documentation recommends 16MiB or more for a server
    • If you do not have sufficient RAM (<4MiB), LED D7 will remain lit, and the card will not appear on the bus
  2. Configure the jumper block in the upper right corner
    • Position 1 (A): Enable SCSI termination on Bus A
    • Position 2 (B): Enable SCSI termination on Bus B
    • Positions 3-8: Unknown
  3. Install the card to a NuBus slot in your Mac
  4. Optional: Connect SCSI cable and drives to A or B
    • You can connect directly to the 50-pin internal header, but your card may have 1 or 2 HD50 pigtail cables for connecting drives outside the chassis
    • If you want to uninstall the pigtails, use a screwdriver to remove the single screw on the metal slot cover above the cables
    • The metal plate can then be removed, and the pigtail lifted out of it’s slot
    • Reinstall the metal plate and screw
    • To install a pigtail, follow this process in reverse
  5. Optional: Connect UTP cable (Ethernet Cat 3+) to CDDI port
    • With a crossover cable this can be directly conneted to another MediaNet card
    • Otherwise a CDDI concentrator is required

The card is now installed and ready for use.

Drive Setup

With the card installed you must now initialize the drives in order to store data. While the UI seems to be able to perform these actions, initial drive setup seems to work more reliably when using the diagnostics interface.

  1. Install the MediaNet software
    • The only copy I have is 1.6.1, which still supports OS 8.1 and 68k machines, newer versions may have higher requirements
    • Sonic documentation references versions up to at least 1.6.7, which have so far been lost
  2. Reboot as requested. You should see the MediaNet icon appear on startup. If you card needs a Flash update, you will see an animated pencil icon erasing and writing the Flash, which can take some time.
  3. Open MediaNet Admin
  4. Select Utilities -> Diagnostics
    • This will enter the diagnostic terminal where we can configure the card
  5. In the text box at the top, type scsi format and hit enter
    • This will perform a low-level format of any connected drives
  6. Note this will cause loss of existing data on the drive, type yes and press enter
  7. The drive will format, this can take some time. When formatting completes you will see a log message and the Bus Activity LED will shut off
  8. Now we need to format the filesystem on the drive. Type mofs mkfs and press enter
  9. The filesystem will format, this can take some time. When formatting completes you will see a log message and the Bus Activity LED will shut off
  10. Reboot again for good measure
  11. Open MediaNet Admin again, you should see the local computer appear in the Servers section. You can double click this to configure users and groups.
    • I struggled with this, it took a few reboots and some futzing to get this to appear. You must configure users and groups to make any use of the drives, however, so you can’t skip this step.
  12. You’ll probably want to know if everything is working, and you probably won’t have a CDDI network to test with, proceed to Local Mounting

Local Mounts

You can mount any drive on the MediaNet card locally, but not in the way you might expect: the card does not directly host SCSI drives but instead provides an AppleTalk network accessible via FDDI/CDDI or the local NuBus. In other words, we can mount the drives as network drives even though they’re on the local system.

To do so, we need to tell AppleTalk to use the FDDI network (FDDITalk) to mount disks. Unfortunately this will prevent the use of EtherTalk if you have local AppleTalk file or print servers. Fortunately, if you’re using a newer OS you can keep TCP/IP configured to use Ethernet and mount TCP/IP-based drives while AppleTalk is using FDDI.

  1. Open Control Panels -> AppleTalk
  2. Select FDDI from the dropdown
  3. Close the Control Panel and accept any dialogs

Now we can mount the drive.

  1. Open Chooser
  2. Select AppleShare
  3. Your local computer should appear, select it and mount
  4. You’ll be prompted for the username and password configured above. Enter it and mount your drive
  5. The volume will appear on the desktop

Diagnostic Shell

In MediaNet Admin you can run a pretty powerful diagnostic shell via Utilities -> Diagnostics. Type help to get a full set of commands.

Troubleshooting

The card does not appear on the bus, LED D7 is lit

Your card is failing to initialize:

The Extension shows an X with letters surrounding it on boot

There was an error during initialization. Known codes are below:

These codes are also listed in the extension their indications are unknown:

The card seems good, but I can’t see any drives to mount from Chooser

I’ve found my card takes a very long time to prepare my drive on boot with a 1GiB volume. I suspect this is doing volume consistency checks. You can watch your SCSI drive’s activity light or the diagnostic bus LED on the card after boot, when it is no longer illuminated the mount has completed (or failed) and you can try mounting the volume.

The mounted volume is very, very slow

The card does a benchmark on boot which can be seen via the diagnostic shell’s logs. I’ve found some SCSI emulators don’t do well with the format and the benchmark shows low speeds like 0.15MB/s. Using the volume exhibits the same experience, so it seems some SCSI drives just don’t offer good performance for this filesystem.