[Coco] 512K AND Beyond??? How FAR Beyond???

[RETRO Innovations]

On 12/26/2017 11:23 PM, Joe Schutts via Coco wrote:
> Hi Everyone,
> I have 3 quick questions that I hope the TECHie people (like Ed Zipster and some of the others) can probably answer.
> The original CoCo 3 came with 128k and then there was the upgrade to 512k. Then someone else (I think it was Disto??) made a 1 Meg upgrade and someone else either built (or designed and did/didn't build) a 2 Meg upgrade. I seem to remember reading an article about it somewhere, but I could be wrong. My question is WHY hasn't someone else like Ed (or even somebody else) built a 1 OR 2 Meg upgrade kit for sale???
I know email doesn't express tone very well, but your style (caps on 
"why", phrasing as negative rather than positive) seems substantially 
accusatory for such a question.  It suggests that such an upgrade is a 
<diety>-given right and Ed or others should be ashamed if they have not 
denied all other life activities in order to bring this solution to 
market before now.  I will make an assumption that such was not your 
intent, but I can attest that (as one of the "somebody elses" who design 
such hardware) such an emphatic question does not come across as benign 
in email.

For one, building an upgrade beyond 512kB is substantially more complex 
than simply putting more RAM on a 512kB design, so that's one reason.  
The Coco3 was designed to only expand to 512kB, and moving beyond that 
amount requires adding functionality to GIME in some fashion.

The DISTO design you mention was indeed such an expansion, and it 
required either soldering a secondary PCB to the Coco3 CPU or 
unsoldering the CPU and replacing with a socket, which is not a simple 
affair.  In the 80's, that was not an optimal option.  Now, it is 
objectionably horrid:

  * In the 80's Coco3s could be sourced.  Now, they cannot.  Thus, any
    damage to the unit is not only inconvenient, it could be permanent,
    depending on how the modification was performed
  * DISTO no doubt handled many customer service calls over the design. 
    unless the additional PCB was professionally installed, there are
    literally hundreds of issues that could develop
  * In the 1980's, home computer were seen as utilitarian and
    potentially throw-away electronic gadgets.  Now, preservation of
    such a unit is much more important.  With that in mind, I think the
    community would be extremely alarmed to see a DISTO-like solution
    that required substantial modification of the Coco3 put into
    production again.
  * As a hardware manufacturer, even if the community sees no issue with
    such a solution, I have no desire to cause harm to a machine through
    the use of my solutions, and thus I would not undertake such a
    design.  I can't speak for Ed directly, but his work suggests he
    would agree with that sentiment to at least a large degree.

However, to answer your question, folks have been working on such a 
thing (there may be others):

http://www.go4retro.com/products/cocomem/

Why hasn't it been put on sale?

Quite simply, it takes time to move an idea from prototype to 
production.  Once the idea has been proven, the design must be 
considered from a market perspective:

  * How many people want more RAM than a Triad 512kB expander, which is
    currently on the market (and as others note, is the most RAM that
    many things outside OS9 will consume)
  * How much more RAM makes sense?  OS9 can't directly use more than
    2MB, relegating >2MB to RAMdisks and such.  Thus, 4 or 8 might make
    sense, 16M/32M/64M less so.
  * How much will people pay for RAM beyond 512kB?  DISTO may not have
    sold many of the 2MB Expanders because it was much more interesting
    to know such a thing could be done than it was to actually own it.
  * How many people will buy such a unit?  I can tell you with certainty
    that I cannot economically manufacture items for less than 100
    potential buyers.  Ed can afford to perform more manual assembly and
    no doubt has lower volume requirements than I, but I suspect even he
    has a lower bound for such a complex solution.
  * How does such a RAM expansion fit in with a future containing
    solutions like GIME-X?  Givne the size of the community, it is
    important that designers not force the community to "splinter" over
    expansion options.

> Last question. Is it possible to access even more memory (higher than 2 Meg) with a CoCo 3 and if so WHY hasn't someone built (or even designed) a board and sell it here???
As noted above, it has been designed, but there are tests to complete, 
feature criteria to finalize, and design aspects to finalize.
> You listening Ed??? Just kidding...
I should probably let Ed chime in here, but be aware that such 
statements (even with the caveat) put a lot of pressure on Ed, whom I 
assume has a "Real Job" that does not involve Color Computers.  Ed 
manages to do quite a bit per unit time (color me impressed), but 
comments like the above make it seem like the community expects Ed to 
continue at his current pace for all time, which may not be 
sustainable.  I can tell you that, like Ed, I have historically managed 
similar spurts of great progress on project ideas, communicated to the 
community that progress, saw people then begin to expect that same level 
of activity in a sustained fashion, and have now forced myself to skip 
announcing progress to the community to protect myself from the barrage 
of "why isn't this finished/built/for sale/designed" questions that make 
it hard to read lists like this.  If you feel Ed is a blessing for the 
community, I'd encourage you to ensure your expectations of him do not 
serve to overwhelm him to the point he regrets things.

Jim