Mac Musings

Project Macard: Compact Flash, USB, and WiFi for pre-PCI Macs

Daniel Knight - 2007.08.15

Have you heard about BlueFlash? It's the newest card for the Apple II computers.

Yes, Apple II computers. People are still using and developing for these machines from the late 1970s.

BlueFlash adds USB, Bluetooth, Compact Flash, and RAM disk support to these ancient 8-bit computers. If only someone would do something like this for ancient Macs!

Think about it: Except for the Mac 512Ke, every Mac from 1986 through 1997 has SCSI, which is faster than the bus in the Apple II. There have been a few SCSI Compact Flash readers. There have been a few SCSI ethernet adapters. (There were even a couple of SCSI video adapters.)

What if you could connect a small box to the SCSI port on your Mac Plus, SE/30, Color Classic, or Mac Portable that gave it wireless networking, USB ports, and the ability to use Compact Flash as a hard drive? What could you do with it?


Remember, this was the era of 20-40 MB hard drives. Megabytes. A 32 MB CF card or USB flash drive could be plenty of space. And it's cheap. And it's whisper quiet. And it's removable, so you could load files onto it from your modern Mac. BlueFlash has been tested with 1 GB CF cards; most vintage Mac users wouldn't know what to do with that much storage space.

Ideally a "BlueFlash Mac" would give us least two USB ports and one Compact Flash slot.


Then there's wireless. Bluetooth is a decent, slow, short-range protocol that might be adequate for networking. Slow, as in 721 kbps with Bluetooth 1.1 or 3 Mbps with Bluetooth 2.0. Not bad compared to 230 kbps for AppleTalk, but slow compared to 10 Mbps ethernet or 802.11b WiFi.

Short-range, as in about 30' (10m) between devices. Enough to share a connection within a room or maybe with a computer in the next room. Decent, but not fast.

The original SCSI protocol had a 5 MBps (or 40 Mbps) maximum, although some early SCSI Macs (notably the Plus and SE) couldn't come close to that speed. The Mac Plus, limited to 2.1 Mbps (or 0.26 MBps), is the only SCSI Mac slower than Bluetooth 2.0's highest data rate.

And then there's 802.11 WiFi. The 802.11b specification, used by the original AirPort cards, has 11 Mbps bandwidth but realistically maxes out at about half that. 5.5 Mbps is faster than the Mac Plus can move data, but it's almost exactly as much as the SE can handle.

Possible Solutions

Probably the simplest solution would be to create a SCSI box that accepts PC Cards (formerly PCMCIA). With a PC Card that accepts Compact Flash, you could create a flash drive. With a PC Card that supports USB, you could add a Bluetooth dongle. And with an 802.11a WiFi PC Card, you could have wireless networking. Just add drivers.

Solution A could be fairly compact, and it would probably require a power supply (although it might be able to tap that from an ADB port). It would be simple, as you wouldn't have to design a CF interface, a USB interface, or an AirPort interface. That hardware already exists. We'd only need drivers for System 6 and 7.

It would also be more flexible, as it could support other types of flash memory, such as SD, and ethernet and modems and who knows what else. Just add drivers.

Another solution would be more along the lines of BlueFlash - designing a board with its own circuitry to bridge SCSI to Compact Flash and USB and PC Card. More elegant, maybe, but much more time involved in designing, prototyping, and debugging.

Solution B is probably less practical, so let's focus on the PC Card adapter.

It's Already Been Done - Sort of

Microtech PCD-40There have been SCSI devices that work with PC Cards, including the Adtron SDDS Cardpak™ PC Card Drive (1 and 2 slot versions, internal), the Microtech PCD-40 SCSI External PC Card Read-Writer (1 slot, external), the MagicRAM SCSI PC Card Drive (2 slots, internal), and the Kodak Compact Flash PCMCIA/PC Card Reader (external). These were used primarily to allow photographers to read their CF cards on their pre-USB Macs.

To the best of my knowledge, all of these devices have been discontinued. I can't even find them listed on eBay.

These four devices demonstrate that the adapter can be built, connecting two PC Card slots to SCSI, allowing older Macs to use them. We'd want to be sure the adapter is bootable (assuming a bootable CF card), and it should have two PC Card slots. This could allow CF (using a PC Card CF adapter) and WiFi, CF and USB, or USB and WiFi at the same time. Anyone needing all three would need an additional device, whichi SCSI supports.

Hardware is probably the easy part compared to writing device drivers for System 6 and 7. I'd suggest making the drivers an open source project - or set of projects.

Naming It

The goal of this device isn't giving SCSI Macs Bluetooth or Compact Flash or USB or WiFi. The goal is giving pre-PCI Macs the ability to use PC Cards that support WiFi, Compact Flash, and USB - and using a Bluetooth dongle with the USB card if someone wants USB. This might also be a way to use a USB mouse or keyboard with a vintage Mac.

I propose calling this the Macard SCSI Adapter. As far as Google can find, Macard isn't being used as a product name. Besides, we don't really want "PC" in the name of a Mac device. :-)

BlueFlash sells for US$160 including a Bluetooth dongle. I'm guessing there's a much broader audience for the Macard SCSI Adapter, and it may even be possible to buy an existing design from one of the companies named above. I'd guess this could sell for under US$100 including an AC adapter and an ADB power dongle.

If you're interested in being part of such a project, whether on the hardware or software side, please email lowenddan (at) gmail (dot) com. Thanks!