[Coco] Sdc copy, and multi pak upgrade question

[Gene Heskett]

On Thursday 04 December 2014 17:55:42 Scott O'Brien did opine
And Gene did reply:
> I have finally joined the esteemed club of CoCo3 owners (they don't
> seem too common here in Australia, judging by what is visible on
> ebay).
> 
> I got it with an 26-3124 MPI (also a first for me).
> 
> My question is, if I open it up, how do I tell if it has had the
> necessary CoCo3 modification made, Tandy-sourced or otherwise?
> 
> Is there any documentation on the Tandy modification?
If it has a seal over one of the screws in the bottom, its a 99.9999% 
chance it has not been fixed. AFAIK, Tandy never offered a fix that I know 
of.  And I'd have doubts about their ability to actually fix it if yiu 
gave it to them at any time in the past 28 years. Mark has the kit, 
although I'd imagine it would take a while to get one mailed down where 
your toilets flush backwards :) I'd expect its doable, but ask Mark for 
sure. Its been 20 some years since I did that to the two I have & IIRC one 
was a 26-3024 and the other was a 26-3124 so there was 2 different kits.
They either was a problem for me, but I am a C.E.T., but now retired long 
enough that my 80 yo hands are getting just a bit shaky.  But that didn't 
stop me from assembling my cocosdc kit in about 2 hours, half of that 
spent discovering that my fawncy new $140 solder iron hot air rework 
station no longer had a soldering iron.  Something blown on te motherboard 
it it, I suspect one of the MOC's used for linear to logic isolation has 
died.

So I rummaged in my midden heap and came up with an original 60 watt temp 
regulated iron that considering it has well north of 50k hours coming on 
with the bench lights every day for 30 or so years  Still works, original 
heater element too.  New in 1960, Cooper Tools wanted to give me $200 for 
it in about 1995 when they heard it still worked.  One doesn't sell a 
valued old friend...  And I've tossed 5 or 6 of their newer ones that quit 
in a couple years.  They don't make em like they used to, but that applies 
to me too I guess.  Darn it.

> Cheers
> 
> Scott
> 
> 
> Date: Mon, 01 Dec 2014 21:57:30 -0700
> From: abqpenmaster <abqpenmaster at gmail.com>
> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> Subject: Re: [Coco] Sdc copy, and multi pak upgrade question
> Message-ID: <gj2fji9q76xv3mmocj5riowj.1417496250640 at email.android.com>
> Content-Type: text/plain; charset=utf-8
> 
> Thanks Gene, I'll get that done.
> Sean
> 
> 
> Albuquerque,  NM USA
> 
> <div>-------- Original message --------</div><div>From: Gene Heskett <
> gheskett at wdtv.com> </div><div>Date:12/01/2014  8:28 PM  (GMT-07:00)
> </div><div>To: coco at maltedmedia.com </div><div>Subject: Re: [Coco] Sdc
> copy, and multi pak upgrade question </div><div>
> </div>On Monday 01 December 2014 11:09:46 seanruss08 . did opine
> 
> And Gene did reply:
> > I got a shiny new sdc, thanks Darren & Ed.  Question though:
> > 
> > I have been able to use the drivewire to copy programs from pc to
> > coco floppy with the sdc card in my multi-pak,   but is there a
> > command to copy from PC to the sd card through drivewire?  Like copy
> > this to that,  or similar command? I have not been able to this far.
> >   Or does everyone just use the PC to setup the files on the card? 
> > Also,  ok to setup files/directories on pc?
> > 
> > I ask because right now the only card reader is on my printer and it
> > is adamant that I am not allowed to write to an sd card. I have a
> > better card reader on order.
> > 
> > Also,  right now I am using a stock multi-pak (26-3124) that has not
> > been upgraded.  I bought it off ebay. I took the cover off and it's
> > not upgraded.  It seems to work great though with my Coco3 haven't
> > seen any problems,   should I have it upgraded anyways?
> > Thanks,  Sean R.
> 
> Absolutely.  It shares its slot switching via a poorly decoded chip
> select ghost that means a white to $FF7F to change the slot, will
> crash nitros9 by mapping out the normal $3F used for the top 8k of ram
> as it will write to $FF9F which is in the multipak.  Conversely, a
> write to the gime chip will muck with the slot or irq transmission
> ability's of the multipak.
> 
> Mark at cloud9tech.com has kits for both or all 3 versions of the
> multipak.  Or he can install them for a nominal fee if you send him the
> multipak.
> 
> But part of that danger will go away forever if you tie all the slot
> sockets together at each sockets pin 8, which will bypass the slot
> logic and allow an IRQ from any slot to reach the 6x09 in a fraction
> of a microsecond.  That means no more missed interrupts from the
> serial port, losing characters when online thru it.  But, that will
> load down the per pin IRQ pullups by making what ever is pulling that
> line down to assert the interrupt work 4x harder because when the
> bridging wire is in place, it has to pull down all 4 of those
> resistors. Put a meter on one of the pin 8's and check the resistors
> along the front edge of the board, and cut the first 3 that you find
> have only an ohm or 3 from pin 8, loose on one end.  The 4th one you
> find and leave alone is plenty of pullup to maintain the logic 1 when
> no interrupts have been asserted.
> 
> This is actually 2 independent problems, but you might as well do them
> both while the covers are off.  I fixed mine about 28 years ago.
> 
> Cheers, Gene Heskett
> --


Cheers, Gene Heskett
-- 
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