[Coco] MPI replacements?

Frank Swygert farna at att.net
Thu Jul 8 12:07:35 EDT 2010


I remembered at least one MPI replacement -- the Slot Pak II (and later III?).
Found some more info on it at http://entropy.tmok.com/~tumble/cfaqs/COCO.FAQ.
It seems that "our" very own Chris Hawks designed and sold it, maybe he could
be talked into making another run? Only three slots though.

A company called "Orion" also made a three slot MPI replacement. It had the
cartridge connectors on a cable though. That would make it the best choice
for repackaging a system where the carts weren't going to be moved much --
they would have to be secured somehow inside the repack case.

This is the ONLY mention of these devices I could find using Google (searched
for "coco slot pak" and "coco xport"). I'd check the Rainbow archives for
pics, I do recall seeing at least the Slot Pak in ads. I'd check about a
year after the demise of the MPI... 1989 and later?

----------------------

  Slotpak (as excerpted from Marty Goodman's review by permission)

There are now two new entries into the field of Multipak replacements:
Howard Medical's "Slot Pak II" (designed by Chris Hawk of Hawksoft) and
the Xport from Orion.  Both offer three buffered slots.

     .....
External Appearance:  The Slot Pak II (SPII) is packaged in what appears
to be an old, full size, disk controller plastic  case.  There are three
40 pin edge card sockets sticking up on top  of the case thru holes in
the case.  There is a jack for connection to a 12 volt wall transformer
(supplied).  Glued to the bottom of the pack is a U-shaped piece of plastic
that supports the SPII, so that the weight of devices plugged in to it does
not produce leverage that would deform the CoCo's 40 pin expansion socket.
This is a nice touch, for the SPII plugs directly in to the expansion socket,
and cards plug in to the three slots on the top surface of the SPII.  There
are no mechanical guides for ROM packs or cards... the edge card connectors
are their sole support...

...The device uses ten small scale (74 series) logic chips internally --
three for buffering address and data lines and the rest for slot selection...


    XPort by Orion  Technologies excerpted from a New Product Release.

The XPort  is  Orion's  answer to the latest of Tandy's casualties, the Multipak
Interface. While the XPort  is  not  a true duplication of the Multipak, it
contains all of the necessary features that the common Color Computer user needs
  - Multiple slots, a fully buffered  bus, slot switching, and a  power  supply
external  to  the  CoCo  for the added cartridges which includes +5 and +/-12
volts.

... We offer not just two, but three slots with which to  work.  These  slots
are  configured  to  allow  hardware  switching of the cartridge ROM in two of
the slots, with the third slot being utilized for cartridges that have no internal
software  - such as the Telepak II,  Tandy's  Speech and Sound cartridge, a MIDI
cartridge, etc.

We gave the XPort something that  was  sadly lacking with the MPI, and that was
MOBILITY.  Since the XPort terminates  as  a  cable,  the  working end of  the
cable  with the peripherals installed can be moved out of sight by merely placing
them  where you like within 15 inches of your computer's cartridge  port.  The
buffered bus allows  a  stronger signal, allowing the longer cable length than a
standard "Y" cable.

The XPort's  internal  circuitry  will  be  powered  by  your Coco, drawing less
than  a  standard  disk   controller,   and  all  external peripherals will be
powered by an external wall transformer (supplied) and voltage regulation circuitry
that  is  external to the Coco's own  power supply. The +/-12 volt (30 mA  max. each)
is provided by a DC-DC convertor in the  XPort, and supplies enough power for  the
Burke and Burke XT interface, an older 12 volt contoller, or other devices (such
as Disto's RS-232 cartridge).

The XPort has been designed to allow  all I/O to occur from address&HC000 (49152),
the external ROM address, and up. ...

-- 
Frank Swygert
Publisher, "American Motors Cars"
Magazine (AMC)
For all AMC enthusiasts
http://www.amc-mag.com
(free download available!)




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