Subject: Macintosh...

From: Juri Munkki <[email-masked]>
Date: Fri, 11 Oct 1991 19:41:23 +0200

As far as I know, Macs do not have parallel ports. Of course it is possible
to use a SCSI port as a parallel port, but it takes some logic and if you
keep things simple, you have to forget about using a proper SCSI protocol.

The serial port should be quite adequate for the glove. The only problem
is that there are only two serial ports. I already have a modem connected to
the other and will soon have localtalk on the other. This still leaves the
Sega 3D glasses and my audio sampler unconnected.

A 68HC11 board with a SCSI interface would probably be the optimal
solution. I could connect the sega glasses and the powerglove to this
hardware box. I assume that at least some versions of this processor
have some EPROM and RAM, so the board would need a clock crystal,
a SCSI-chip and a VIA. The 6522 VIA has a shift register that could
easily be used to read the glove. The other I/O lines could be used
to control the Sega glasses.

I know someone at Microsoft who has a small ADB box based on an Intel
processor. I don't know how well his system works, but I do know that
ADB provides +5V and it has some room for expansion.

   ____________________________________________________________________________
  / Juri Munkki	    /  Helsinki University of Technology   /  Wind  / Project /
 / [email-masked]  /  Computing Center Macintosh Support  /  Surf  /  STORM  /
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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From: Jay A. Carlson <[email-masked]>
Date: Fri, 11 Oct 91 16:28:11 CDT

> to control the Sega glasses.

Unfortunately, the versions of the HC11 with EPROM instead of
mask-programmed ROM are still quite pricey.  If you plan on bringing
out the bus to the SCSI chip anyway, hooking an external EPROM up is
more cost-effective.

The HC11 also has a SPI, Serial Peripheral Interface, on-chip.  It's a
more general version of the shift register of the VIA.  There also
should be plenty of I/O lines on-chip left over to drive your glasses.

If we remove the VIA, the parts list is now an HC11, a crystal, a
2764, a latch and maybe a '138 to drive the bus, and the SCSI
controller.

The same hardware, substituting an RS-232 line driver for the SCSI
chip, could be used for a universal serial glove interface.  I don't
know that much about the Apple Desktop Bus, but I know that HC11
series chips live in some ADB devices.  And finally, you can run data
out the serial port at MIDI rates, making the hypothetical board of
some interest to musical types.

I wonder how much demand there'd be for one of these boxes....

  // Jay Carlson
\X/  [email-masked]

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