[Coco] make-do ROM Paks

[Gene Heskett]

On Monday 17 September 2007, Mark Marlette wrote:
>Roger,
>
>I sill have about 300 full size cases. Bought all stock out when
>vendor was going out of business. Tried to get some half size ones
>from a former vendor but I was to late when I contacted him. He threw
>them last summer. :(
>
>I have a template that I use when I make the SuperIDE cases at home.
>There is a fair amount of clean up required and the SuperIDE takes a
>bit of time to assemble and get out the door. Soon to have the
>SuperIDE stocked and on the shelf. Can't remember when we released it
>but I haven't to date been able to keep up with the orders. That is
>all changing.
>
>I'll be milling the cases on a Bridgeport shortly and will require no
>touch up when completed.

Mark, does your Bridgeport do CNC?  I have a 3 axis micromill with expanded 
table capacity being run by emc2, and the case sizes contemplated would be 
right up this puppies alley.  I can do 5.5x12 in a pinch, with about a foot 
of z available, all to about .0001" accuracies at 10 ipm in any direction.  
Code format is RS274D.  I can do lights out manufacturing, one piece at a 
time.  Current cutters in stock are 1/4" flat and ballnose, 1/8" flat and 
1/16" flat, plus a lot of the dremels carbide catalog.

I just built a new z axis drive for it.  I'd rebuilt it immediately after 
buying it with a much better screw, but the basic design was so bad I 
couldn't even reliably drill a hole in wood as it was binding the heads gibs 
if any downforce at all was required.  I moved the driving screws attachment 
to the head's sled to a point 3.3" in front of the post, reducing the binding 
force on the gibs by about 2 orders, so I can now push a drill bit with about 
150 pounds, 50x what it would take to drill plastic.

If you can get your cad proggy to spit out RS274D, not to be confused with 
RS274X aka 'gerber' photoplotter, toss me a sample by private email & I'll 
see if it will run here.  It might be an interesting experiment.  But I've 
not found a converter that can take RS274X input and output RS274D.  The X 
version throws away way too much of the cad proggy's vision of the part.

>Mark
>Cloud-9
>
>Quoting Roger Taylor <operator at coco3.com>:
>> At 03:16 PM 9/16/2007, you wrote:
>>> If you end up needing to get a 'mess of boards' made, why not just
>>> go with a design that uses a 28-pin socket to accept
>>> 2764/27128/27256/27512 EPROMS?  I have already created a prototype
>>> layout for such a board using the ExpressPCB software. I can send
>>> you the layout file if you like. You can view an image of the
>>> layout at:
>>>
>>> http://www.coco3.com/users/DarrenA/CoCoPak.gif
>>
>> That's what I was saying ... a mess of boards that use the 2764.  I
>> looked at your design the other day for a few minutes.  Before I can
>> submit something similar to a company to etch I will have to know that
>> it will fit a CoCo port accurately.  Ofcourse, I'm not doubting your
>> hard work.  It's probably ready to go as-is... ?  I know it can be very
>> hard to insert and remove a case-less card in the CoCo if it is brand
>> new or a certain thickness.  My J & M controller to this day is very
>> tight fitting in an MPI or CoCo.  I tried it without the case earlier
>> and I had to wiggle the board, etc.  Doing all of this with a tiny
>> board worries me.  Then there's the issue of making cases
>>
>>> The layout has some jumper pads for configuring the A13 address
>>> line and Auto-Start. The board dimensions have been minimized to
>>> reduce cost, but it could easily be enlarged or reconfigured so
>>> that it could be mounted in a case. The ExpressPCB price quote to
>>> have 10 of these boards produced is $97.65 including shipping, 100
>>> boards would be $396.84. These would NOT have gold contacts on the
>>> connector.
>>
>> Auto-start is a must for my project so I wouldn't use that.  I think 10
>> boards for proof that they work and to detect minute errors would be
>> the best idea, then on to bigger ideas if needed.
>>
>> I wonder if Mark Marlette would disclose how he had those nice SuperIDE
>> cases made, or where.  Then I can compare to the cost of having a sheet
>> metal case done.  The J & M controller has a durable metal case that
>> looks rather simple to duplicate, although I would only go half the
>> length.
>>
>>
>> --
>> Roger Taylor
>>
>>
>>
>> --
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>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco
>
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-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
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-Ed Howdershelt (Author)
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	- Larry McVoy