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pinto_guy

Walkmac

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I recently acquired an original Walkmac (photo below) from the estate of the late Chuck Colby, founder of Colby Computers. The Walkmac used a Mac Plus logic board, and attached an LCD and a battery to package an arguably fully portable computer (it still missed a keyboard and a mouse), a full year before Apple's luggable. One cool feature is that you could plug in external storage peripherals (FDD and/or HDD) directly into it from the side. See some more discussion on this here.

 

I'm having some issues booting it up, and started a thread here too.

 

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Nice score! I did see that ad but unfortunately I couldn't show up to Mountain View in the morning.

 

 

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I like how the base of the unit has a mouse mat!  We've all seen keyboards with computers inside (Amiga, C64 etc), why not the mouse mat? :)

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I’m a little bit confused about the right side of the machine.  The left looks like it’s all filled with logic board and power supply but the right side seems very hollow.  
 

Is the right side designed to store stuff like that floppy drive I think is pictured?  How hollow is the unit?

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Hi superjer2000. The void on the right side is for the detachable HDD and FDD units. On the photo, only the FDD is attached. Below are photos of the base unit, together with some descriptions I made. The electronics consists of a Mac Plus logic board at the bottom, and a Colby board that sits on top, connected to the LB through the molex J8 connector that usually connects to the AB of the Plus.

 

1) Colby Board (the Mac Plus LB is underneath)
 
Looks like this board is mainly for power management. I am still trying to figure out where the battery was (internal, external - does anyone know ?). Colby's "secret sauce" was in converting the Apple video signal to one that's understood by the plasma screen, but it looks like this happens all in the plasma screen assembly itself.
 
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2) Mac Plus LB
 
Besides the typical connections from the Mac Plus to the outside, still available here (more below), we have a few items of importance. 1) Connections of the optional FDD and HDD to the LB is via ribbon cables (not shown here). The HDD connection to the SCSI chip is the most bizarre and unreliable one (not shown here)   2) Since the keyboard connector (phone jack) is in the front on a Mac Plus, Colby needed to have a connection made to the back, hence a pass-through connector to the Colby board 3) Same for the reset buttons that are now hidden. A small connector allows to connect the reset line to a small red reset button in the back 4) Finally, a red cable borrows a signal from the LB, and sends it to the "video out" connector. More on this in the next section
 
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3) Mystery Signal Connector
 
The red cable to the "Video out" connector attaches to Pin 2 of a "Hex Inverter" (MC74F04N) on the LB. No idea why. They built an elaborate green connection board that sits atop the silver "FOX" oscillator chip. A ground connection was also there on pin 7, but it's actually not used (connector was cut so to not include the ground). This signal is necessary, as the screen does not display without it (I tried). Does anyone know what signal is on pin 2 of this chip ?
 
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3) Side View
 
Here you see the Walkmac folded, with the plasma unit on top. Note that the plasma unit is powered on its own, separate from the computing unit. The bottom row of the computing unit has the usual Mac Plus connectors, and the 120V power input and switch (left). The top row has the keyboard jack, and multiple power input/outputs, and also two switches. I'm still trying to make sense of them. A small red "reset" button (extreme right) connects to the Mac Plus programmer switch.
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Now you just need to pair it up with a vintage Walkman.  ;)

 

On 9/15/2020 at 4:28 AM, pinto_guy said:

Colby's "secret sauce" was in converting the Apple video signal to one that's understood by the plasma screen, but it looks like this happens all in the plasma screen assembly itself.

The upside is that that means it's possible to convert the Apple video signal to something else.  If someone could figure out how to convert the Apple video signal to a driver board for an LED display, that would certainly help for when the CRTs are all dead and gone.

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Well you can certainly jigger something to output to a TTL type deal, and from there you could convert to VGA and whatnot with off-the-shelf converters.

 

Plus, I am dead set on having a stash of good CRTs sealed away somewhere so I can be the last one running original macs :P.

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15 hours ago, brlawyer said:

Amazing - didn't even know that thing existed. So it was based on the Mac Plus MOBO? Was it legally sold or struck down by Apple at some point in time?

Yes, based on a Mac Plus LB. As for the business question, we're still trying to figure it out. The person who I acquired this from knew Chuck Colby, and says that he had a Joint Venture with Apple. Colby and Wozniak knew each other for sure, and I saw an email from Woz to Colby (before he passed away) acknowledging his contributions to the Hi Tech world. But it is my opinion that he did not have the rights, and the Walkmac was simply a perfectly legal Macintosh Conversion machine. See Wikipedia's article on this https://en.wikipedia.org/wiki/Macintosh_conversion

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I have nothing to contribute here, other than my sheer astonishment and delight that a WalkMac is alive and running in 2020. I have vivid memories of reading about this thing in some Mac-centric magazine when I was a kid (maybe a mention or write-up in MacWorld or another magazine of that era), and just being blown away at the idea of using Mac software on a crazy-cool orange plasma display.

 

I'm so happy that this machine has been saved from whatever sad fate presumably befell most of the other WalkMacs that would've existed back in the day. Please keep sharing any further developments or discoveries about this machine!

 

Huxley

 

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