[Coco] Dual UART with FIFO Card for the CoCo

Mon Jun 14 00:15:00 EDT 2010

I'm 21. My dad is 42. He taught me all I know.

I have a heart condition (both of my parents have heart disease so I guess I 
was genetically doomed before I was conceived.)

It's actually manageable as long as I remember to take all these darned 
pills everyday. At one point, I awoke to find both of my feet had turned 
bluish-purple and had no feeling, but luckily circulation returned before 
permanent damage. They were afraid that some of the nerves in my feet had 
been damaged because I couldn't feel my feet for almost a month. They 
subjected me initially to a test where they applied electrical current to 
the surface of my legs. When I was unable to feel that, they scheduled me to 
see a specialist who attached electrodes to my legs and then started 
sticking needles into my legs starting with my feet. I couldn't feel any of 
it until they got to just below my knees at which point I yelled. They told 
me that I likely had nerve damage and that nerves could not regenerate so it 
would be permanent. Fortunatly, about a month later, I began feeling my big 
toe of my left foot. Slowly, all feeling returned to both feet, so there was 
no nerve damage (well, maybe a little but not much). This was before they 
diagnosed a heart problem - in fact they could find no reason for it. 
Eventually, my blood pressure rose so high (staying between 176 and 200 over 
100 to 110) that they began looking harder. It took them 3 years to get 
everything under control. I still sometimes wake up gasping for breath and 
it really scares me, but it doesn't happen as often as it used to.

I posted a little about this on CoCo3.com, but I didn't include all the 
details. I mainly posted it because my memory is sometimes affected and I 
wanted people to understand if I forgot something, or if I repeated myself 
needlessly - it's because sometimes I just can't remember...

Recently, my Mom was diagnosed with breast cancer on top of everything else. 
They removed the tumor and she is going through chemo now, which really 
compounds my situation.

So you folks can see, I really needed something to keep my mind occupied. 
CoCo3.com and this list have given that to me. I can design stuff for people 
and post it on CoCo3.com which is cool because if I should experience a 
sudden "decline" - at least you guys will remember some little part of me 
:-) I know that's gloomy, but when it comes down to it, we're all mortal, so 
I've just accepted it and do the best I can - and I smile at least once 
everyday because I just won't give up and neither will my mom :-)

CRAP - I WENT ON A BIT OF A RANT THERE DIDN'T I?

Anyway, all of my CoCo knowledge has been gained in the last three years. My 
dad had told me about the IRQ mod to the MPI and an additional internal 
CoCo3 IRQ mod that goes with it, but I had forgotten (my memory woes...), 
but your email triggered the memory which is cool.

Well Gene, I've probably bored the crap outta you, so I'll end this lil' 
rant of mine and get back to work on the CoCo projects. It gives me much 
enjoyment to create this stuff to share with everybody.  --John

----- Original Message ----- 
From: "Gene Heskett" <gene.heskett at gmail.com>
To: <coco at maltedmedia.com>
Sent: Sunday, June 13, 2010 10:32 PM
Subject: Re: [Coco] Dual UART with FIFO Card for the CoCo

> On Sunday 13 June 2010, sales at gimechip.com wrote:
>>Gene,
>>If the Duart Pack is used in a multi-pak, and the disk controller placed
>> in a different slot, it wouldn't interfere with the RTC inside of the
>> disk controller. Since I used the SCS* signal, the duart pak would only
>> be active when it's slot has scs* directed to it. Any pack that doesn't
>> need $FF50-$FF5F could still be plugged into the duart packs feedthru
>> connector.
>
> Hmmm.  You are aware, and I don't think this effects SCS steering, that 
> many
> of us have solved the IRQ latency problems by jumpering the pin 8's of all 
> 4
> sockets in the mpi together, and removing 3 of the 4 pullup R's?  This
> bypasses the IRQ logic in the slot selector so any IRQ from any pack gets
> through to the cpu instantly.  Then by setting the priority byte in the
> driver, os9 can find the src of the IRQ and service it pretty fast.  In my
> testing, 15 u-secs was the average response time except when all IRQ's 
> were
> locked out while the old B&B clock chip was being read each minute, and 
> that
> usually cost about 140 u-secs.  No more missed characters when 
> downloading!
>
>>I will probably do another design using a quad uart chip and I can allow
>>alternate mapping schemes such as the $FF1x or $FF3x area which is
>> available on the CoCo3 (but not on the CoCo 1 or 2). If I do a quad pack,
>> I will probably map them into 16 bytes and include a "switch" so that you
>> switch in the first set of 2 or the second set of 2 uarts. I would
>> probably also include a SR latch for each of the four UARTS such that
>> when one of them generates an IRQ* it sets it's corresponding latch - the
>> four latch bits will have an input port so that, if needed, the coco
>> could decide which of the four uarts generated the IRQ*. These are just
>> some ideas. I suppose I could actually map all four UARTS into the same 8
>> bytes with a "switch" to select which of the foure uarts occupies the
>> memory space... these are just some thoughts, but if you think it's worth
>> looking into, I'll go to work on it. I am having fun with all of this :-)
>>Since my Doctor has yet to clear me to go back to work, designing this
>> stuff keeps me from going bonkers.
>
> Chuckle, BTDT.  And you are doing the sort of things I did out of 
> necessity
> 2 decades or more ago when I was working in broadcast engineering.  Yes, I
> had a blast at the time.  I enjoyed the looks of other faces when 
> something
> I did with very few resources, worked, and worked reliably.
>
> I wrote the program in B09 and made up a bit of cabling to plug into a GVG
> 300-3A/B production video switcher so I could use a coco 2 & a couple of
> floppies, running os9 level 1v2 as a personality storage device, doing the
> same job as an accessory GVG sold for $20,000 called an EDISK, except mine
> gave the tech dirs english language names for their files, and was 4x 
> faster
> than the GVG gizmo.  Used it for 16 years, till we had to get a newer
> switcher.  At which point they gave me that computer.
>
> Now I am 75, and I was going to go help the next door neighbor get the 
> paper
> on his new garage roof, and with the temps and the humidity both above 90, 
> I
> simply didn't have what it took to get up on the roof and give him a hand
> today, the heat about wiped me out.  So I went out to TSC and got a stick 
> of
> 1/4" rod, a rat trap, 3 nylock 1/4" nuts & some washers, cut it about 7":
> long, threaded both ends and rigged the washers to cover the augered out
> holes in the sheet metal on my MTD chippers big stick input chute, welded
> those in place, took the rat trap apart to get one of the springs to hold
> the flapper in the chute entrance closed, re-welded the lower lip where it
> had broken away from the knives hitting the wood its chopping up, and put 
> it
> all back together.  It should be good for another 20 years now even if I'm
> not.
>
> If I can be a little nosy, and I'm assuming that you are a bit (30 years
> maybe) younger, do you care to share why the Doc's have you on the shelf?
>
> -- 
> Cheers, Gene
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> A journey of a thousand miles begins with a cash advance.
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco

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