[Coco] Re: Let me introduce myself (GW/CoCo BASIC similarities)

[Gene Heskett]

On Sunday 05 February 2006 04:47, Richard E. Crislip wrote:
>Hello Gene
>
>Thanks for the reply, I am not sure what those caps are that you are
>refering to, but I would guess that that would be my next step. I have
>already removed and cleaned all the socketed parts (including the
>daughterboard. No joy. So the caps seem like the next target. Could I
>purchase them, cut the old ones off and solder the replacements on to
> the place of the old ones? I'm not good enough and do not have the
> equipment to desolder surface mounted components.

No, that will take a soldering iron that looks like an overgrown set of 
tweezers so it can hit both tabs of the cap at the same time.

The only one I'm fam with is a GC thing, and needs a powerstat to turn 
it down, it gets way too hot after 5 minutes at full voltage. Even 
turned down, it can get the caps hot enough to explode them.  No real 
damage though other than to ones nerves :)

Since measureing those is a pita in circuit, investigate a gizmo called 
a capacitor wizard.  Its a bit pricey at about $175, but it measures 
the caps ESR at 100 kilohertz, the most important cap characteristic 
for digital circuitry.  Anything over 1 ohm is suspect.  You absolutely 
need one of those if you do service for a living.

Also, if there is a commie 040 card in it, be aware that whoever made 
that for commie put all those caps on it bass ackwards, so the failure 
rate is 100% long before now.  They usually fail open, with now dried 
leakage products all over the board under them, and which is somewhat 
corrosive...  Gets into the board and eats inner traces in two where 
you can't fix it, or shorts layers too.  And its crowded, very hard to 
get the iron in there to replace them.  After about 5 of them on that 
board I'm ready to shoot the neighbors cat or something.  It has IIRC 
14 of them.

Absolutely the most piss-poor assembly Ijob 've seen in my 55+ years of 
holding an iron in one hand.

The german made 060 card is a far better card.

>On 02/04/2006, Gene Heskett wrote:
>> On Friday 03 February 2006 13:28, Richard E. Crislip wrote:
>>>Hello Gene
>>>
>>><snip>
>>>
>>>> Needless to say I nuked that pile of steaming poo, and bought a
>>>> copy of SAS/C and never looked back.  I used it, a lot in those
>>>> days. Its still sitting on the shelf about 3 feet away, the last
>>>> version, 6.58. Lots of miggy stuff here, but the 30GB HD in my 64
>>>> meg 68040 equipt 2000 with a picasso-II video card, threw a rod
>>>> and it lost its space on my desk.  Its in the basement now waiting
>>>> for a real collector to come along.
>>>
>>>Yeah, I know that too, but I hadta try ya know what I mean 8-)
>>>
>>>My miggy A4000 is in the process of throwing a rod too. The cursor
>>> keeps jumping horizontally about an inch at a high rate, but
>>> irratically. So when I attempt to open a drawer next to other
>>> drawers, very often the drawer I was trying to open ended up being
>>> dropped in a draw next to it. To make matters worse, my trusty
>>> A2065 ethernet card seems to have packed it in too. <sigh> Sooo I'm
>>> using WinUAE a lot these days. Fortumately, I had copied all of my
>>> typesetting business to that a long time ago. The most the miggy
>>> get used for these days is to make ADF virtual floppies for WinUAE
>>> and E-UAE.
>>
>> Unforch, on a 4000, much of it isn't socketed as they were on the
>> 500/2000/3000's.  If my 2000 started that, it was time to pull the
>> chips one at a time and clean the legs with an eraser, underwater to
>> absorb the static the eraser would generate if used dry.  The
>> miggy's mouse, as we all know, was one of the smoothest mice ever
>> because it had true quatrature detector stuff wired all the way into
>> the position counters in the amiga, which in the earlier ones was in
>> the Paula chip IIRC.  Thats why the mouse cables were so big and
>> stiff, it used all the 9 wires in a db9 connector to do that.  Your
>> 4000 put that function into the alice chip I think, and that puppy
>> is surface mounted.  The other possibility, and a good one on a 4000
>> is that those surface mounted electrolytic caps have now been in
>> there about 7 years past their estimated lifetime, and a general
>> shotgun replacement of them might work wonders for the mouse, and
>> the machines stability over time.
>>
>> We had a pair of 2k's and a pair of 4k's at one time at the tv
>> station. And a 1200 that did the glass logo in the corner of the
>> screen for several years driving a supergen genlock.  It and both of
>> the 4ks died right on schedule 5 years ago, but one 2k, with an F40
>> board in it was still working with typical uptimes of a couple of
>> months running the script that grabbed the telepromter text from the
>> news server in news, made html out of it, and put it up on our web
>> page 5 minutes after the newscast went to air.  This was using an
>> arexx script Jim and I wrote back in early 97, driven by the ezcron
>> we also wrote, and it ran that way, headless, until a few months ago
>> when Jim converted it all to php on linux.  Not as purty, but less
>> trouble to keep it working once the infant mortality bugs were taken
>> care of in the code.  Its still sitting there in the rack, just
>> turned off.  I could take it home anytime, but don't have a place to
>> use it anymore.
>>
>> The longest running machine there was a trs-80 Color Computer 2,
>> running  os9 level one and a program I wrote that made it into an
>> EDISK for the  grass valley 300 series video switcher.  We used up
>> two of those over  the years, till parts got to be too darned
>> expen$ive, but with a  replacement floppy occasionally because we
>> wore them plumb out, that  'coco' sat there and did its job for 15
>> years.  Grass wanted $20,000  for a unit that was capable of that
>> job, but about as handy as tits on  a boar hog.  4x slower than the
>> coco, 2 digit numbers on an led dislay   for files, where the os9
>> based filesystem had real names displayed on a  5" video monitor.  I
>> figured I had $275 in it at the time I built it in  '88, ran it till
>> '03. :-)  Its in a box in the basement now since the  grass 300's
>> been retired in favor of an echolab studio switcher which  has a
>> function similar to what the coco did builtin.
>>
>> Thats why I always called the coco's "the machines that could do
>> it". They could.  So could the amiga's.  Not everyone understands
>> that between the vax's and the amiga's, and toss in a sun or two for
>> good measure, the internet as we knew it say 10 years ago, was
>> invented. All the windows stuff out there now is strictly Johnny
>> come lately stuff.  And they are still trying to catch up.  Heck,
>> IBrowse on an amiga with a decent video card in it is still one
>> great browser today.
>>
>>>Regards
>>>--
>>>Cruising on AutoPilot                        |
>>>        With an Amiga           ---o-o-O-o-o---  and a CoCo
>>
>> Cheers, Gene
>> People having trouble with vz bouncing email to me should add the
>> word 'online' between the 'verizon', and the dot which bypasses vz's
>> stupid bounce rules.  I do use spamassassin too. :-)
>> Yahoo.com and AOL/TW attorneys please note, additions to the above
>> message by Gene Heskett are:
>> Copyright 2006 by Maurice Eugene Heskett, all rights reserved.
>
>Regards
>--
>Cruising on AutoPilot                        |
>        With an Amiga           ---o-o-O-o-o---  and a CoCo

-- 
Cheers, Gene
People having trouble with vz bouncing email to me should add the word
'online' between the 'verizon', and the dot which bypasses vz's
stupid bounce rules.  I do use spamassassin too. :-)
Yahoo.com and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2006 by Maurice Eugene Heskett, all rights reserved.