CoCo Xpndr1 (was: RE: Keep or assemble???

From: Richard Erlacher <edick_at_idcomm.com>
Date: Tue Sep 4 17:11:36 2001

If you take the time to redesign this device, the simplest, lowest-risk,
easiest, cheapest, and least-exposed-to-copyright-infringement will be to
redesign the entire thing in a single CPLD or FPGA, on a board that matches
physically and logically, but in no way infringes on the copyright associated
with the artwork, which is what can be copyrighted. Circuits themselves would
have to be patented, and, folks have found, that's a waste of time, since
generating a logical equivalent circumvents the patent, though not the PCB
copyright.

Once you have a prototype of your new replacement working, put the original on
eBay and take a vacation with the proceeds. ... or don't ...

Dick

----- Original Message -----
From: "Roger Merchberger" <zmerch_at_30below.com>
To: <classiccmp_at_classiccmp.org>
Sent: Tuesday, September 04, 2001 3:46 PM
Subject: CoCo Xpndr1 (was: RE: Keep or assemble???


> Rumor has it that David Woyciesjes may have mentioned these words:
>
> > It sounds like you would get more enjoyment out of building & using
> >it, rather that letting it sit and collect dust. If you're toying with
> >building it, I would say go for it, but keep all the packing and paperwork,
> >too. That helps increase the 'value'.
> >
> >I think it all depends on whether you plan on selling it, or keeping it. I
> >would definitely build & use it.
>
> [snippage, fore and aft...]
>
> I don't necessarily disagree with you, but the "reproducability" would be
> decreased once the kit is built... i.e. you can't [easily] scan the boards,
> or re-design them in AutoCad, etc...
>
> With this in mind, I was digging thru an old box of CoCo stuff I have and I
> came across (2) Xpndr1 expansion cards, 1 of which is virgin. A quick
> search of Google shows nothing about them...
>
> I've started re-designing the card in AutoCad (as if I didn't have *enough*
> projects ;-) with improvements. Some are minor, like putting the signal
> names on the top of the card instead of the bottom (so it's easier to see
> the signal names when I attach a small breadboard to the top of the
> card...) some are major (or going to be) like the extra room for standoffs
> so it'll be self-supporting, and also connector ports for both a "PC hard
> drive power port" and a "PC floppy drive power port" so you can power the
> thing from any PC power supply *or* an FD-50x power supply. I also plan on
> having one that buffers all of the data, address & major signal lines on
> the board, so that experimenting might be easier without blowing the entire
> CoCo bus.
>
> Which leads to my questions:
>
> A) Anybody know anything about the company that marketed these, as I don't
> want to intentionally break any copyright laws; but with no info on the
> internet & the extreme possibility of the company no longer existing, does
> anyone think I'll be in trouble with the law WRT copyright laws? I'm mainly
> just using the original as a pattern for (1) the signal names & pinouts,
> and (2) the dimensions of the connectors & pins (I didn't have anything
> else that had the ground pegs on either side of the connector).
>
> B) I can prolly find this out for myself, but there are many others here
> better than me on the hardware side of things: What would be some of the
> better [a.k.a more useful] buffer chips I could use to buffer the address &
> data busses?
>
> C) Are there any *real* problems with powering the card from a separate
> power supply? I'm assuming I need to tie the grounds together, but I
> wouldn't want the +5 / +12 / -12 volt rails tied at all -- they should be
> separate, right? [[no, I really don't feel like dissecting my MPI just
> yet... altho I think it's the *only* piece of computer equipment I've never
> taken apart! ]]
>
> Should I check the voltage levels of the power supply & the CoCo to see
> how close they are, or as long as they're both within TTL levels is it OK?
> I'm mainly worried about the PC supply being of a higher voltage than the
> CoCo, if that'll cause problems.
>
> =-=-=-=-
>
> The designs (when they get closer to completion) I will have on my website
> for free, but if I make several cards and someone else is dumb^H^H^H^H bold
> enough to purchase one I would sell them for a small profit...
>
> Anywho, thanks for listening, and double-thanks for any advice that others
> might be willing to offer... ;-)
>
> Roger "Merch" Merchberger
> --
> Roger "Merch" Merchberger --- sysadmin, Iceberg Computers
> Recycling is good, right??? Ok, so I'll recycle an old .sig.
>
> If at first you don't succeed, nuclear warhead
> disarmament should *not* be your first career choice.
>
>
Received on Tue Sep 04 2001 - 17:11:36 BST