[Coco] Multi-Pak Interface question.

[Gene Heskett]

On Wednesday 04 March 2009, Christopher Hawks wrote:
>Ryan Pritchard said the following on 03/03/2009 10:11 PM:
>> It would be my understanding that any patent (if any existed) on the MPI
>> would be expired at this point, leaving only a potential for copy-write
>> issues.  Though my thought is if one can buy the PAL fix for the CoCo 3,
>> then one merely has to assemble said parts from a schematic and voila MPI.
>>
>> On the flip side there was mention of Chris Hawk who is still on this
>> list that previously made a compatible/comparable device called the
>> SlotPak III, as was pointed out by Tom Seagrove.  Maybe he would be able
>> to release details on that device if they still exist such that we could
>> see these manufactured again, or at least people could choose to make
>> one themselves.
>
>     I never built the Slot-Pak III. But, I did design it and make some
> early prototypes. Howard Medical and CoCoPro built and sold them. I have
> the schematic somewhere (I think) and I do have a bare pc-board. There are
> no Net-Lists or Gerber files as this was designed in 1988 and the board was
> laid out with pin-striping tape.

Ahh, the old school.  Lay it out about 4x with tape, and run it over to the 
newspaper where their Brown Horizontal would bring it to size and make the 
negative 6 up.  Bring it back, spray some resist on a pcb & let it dry in a 
hot dark box, sandwitch the negative against the pcb, close the exposure frame 
& turn on the vacuum pump to pull things up nice & snug & burn with an arc 
lamp from about a foot & a half for 4 or 5 minutes.  Develop in kerosene & 
drop it into the one relatively high tech gizmo we had at KOTA, a DEA Spray 
etcher.  Once warmed up, it was about 2 minutes for a double sided board that 
had 6 copies of my stuff on it.  Wash it up, cut it up, drill, mount & solder 
parts.  About 2 days and we had 6 copies up and running.  And the notes I'd 
made with a pencil inside the 10x10 grid background as I laid out the tape?  
Perfectly legible in copper .025" high.  High end of the 60's, and I was 
impressed with the 'state of the art'.  Seems like at least an eon ago now.

-- 
Cheers, Gene
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