[Coco] moving files on bootup >> leading to that CNC Coco machine

[John Donaldson]

Back in th late 70's I ws working at the Johnson Space Center in 
Houston, Texas. I ws in the Medical Research Division and a member of 
the Appolo, Skylab, ASTP/Shuttle Pre-Flight nd Recovery Team. One of the 
problems we had was obtaining a accurate heartrate on our test subjects. 
We decided that the most accurate way was to measure the timing between 
heart beats. Up till this time all automated heartrate monitors used an 
averging scheme. That is they counted heartbeats for a 60 sec period 
then displayed the heartbeat. Some supplier had sent me a 8085 eval 
board which had a monitor prom on it. It only had 1K of ram memory, but 
sockets for three more 256 byte Eproms for a total of 1K of Eprom. It 
would hook to a KSR33 for a user interface. I decided to see if this 
littl computer could measure the timing between input pulses from it's 
I/O chip. So I hooked a pulse generater to one of the I/O pins, wrote a 
program that made this I/O pin an Input, then sat in loop waiting for 
the input to go High. When it went High, I then would take the contents 
of a 8 bit regester and calcuate heatrate. Then I took this and sent it 
to a 8 bit I/O port which connected to a 8 bit D/A. The output of the 
D/A went to a strip chart. I then cleared the counting register, added 
to it a pre-determine count, then stated incrementing the regester. 
After each increment, I looked to see if the input I/O pin had gone High 
again. If so then repeat all of the steps. The pre-load of the register 
was to compensate for the processing time. After some tweaking it work 
rather well. One thing I found was it was so fast that I had to put a 
NOP loop in between increaments. I then worked on a input circuit that 
would take a real heatbeat and strip everything off except for the main 
R-Wave and then convert this into a Pulse with a fixed with. The timing 
of this fixed pulse was the value of the preload. It all worked fine 
except in real life a person's heatbeat does not stay the same from 
moment to moment and if you stress a person their heatbeat can increase 
very rapidly. I found that the NOP loop being fixed was causing me 
problems. So I had to change that code to be flexible. That is long if 
the heatbeat was low and short if the heatbeat was high. when I got it 
all working, it not only measured accurating the beta-to-beat heatrate, 
was accurate +-1 heartbeat from as low as 20 BPM to 3000 BPM. Since I 
was measuring heatrate beat-to-beat, if a subject had a PAC or PVA beat, 
that is an iregular heatbeat, it would show up on the strip chart 
looking like a S. This was because it would first look like a real high 
heartrate followed by a real low heatrate, then back to the normal 
heatrate.. I then added code that looked at other I/O pins connected to 
push buttons. This code would put either all zeros or all Ones to the 
I/O port that was connected to the D/A, so it could be calibrated to a 
strip chart. I put all my code into a eprom and only used the 1K of ram 
for strachpat and temp storage of data. I ended up getting a New 
Technology Award from NASA, a $500 cash bonus, wrote up in the NASA Tech 
Brief Magizine, and a joint patent between NASA, my company, and myself. 
I still have my copy ( a little yellow now LOL) of the manual I had to 
write and the certificate presented to me from NASA. I even got an telex 
from a reseacher that wanted to know if my system would measure 
hummingbird heatrates. I wrote back saying if their heatrate was below 
3000 BPM, then yes, He wrote back saying at rest they are 200 BPM and 
flying as high as 600 BPM. I sent him a copy of the manual. The manual 
contained everything you needed to re-create my system, include all 
circuit diagrams, and source code. BTW, I had no assembler, so I hand 
assembed all of the code. For doucmentation, I also had to hand calcuate 
all timing loops, all code loops, and etc. Since all of my code fit in a 
256 byte Eprom, it was not be bad of a job.




Willard Goosey wrote:

>On Sat, Feb 02, 2008 at 03:45:33PM -0800, Kevin Diggs wrote:
>  
>
>>>Gene Heskett said the other day."a coco doing actual work!"
>>>      
>>>
>
>  
>
>>I remember reading this. Don't think it was Gene though. He has 
>>"stitched" various home brew do-hickies together at the TV station. At 
>>least one of which was a coco.
>>    
>>
>
>That was me, and I was being sarcastic.  The CoCo was (and still is)
>quite capable of real work, not that anybody ever convinced Tandy of
>this... :-(
>
>And, man, I'd love to get my hands on some of the homebrewed hardware,
>especially Boyle's 8-port serial cards. Think about it a moment: A
>CoCo with 8 serial ports.  A boy can dream.
>
>Heh, don't mind me, I've got a serious weakness for computers with
>*lots* of serial ports, and I'm going to go sit in the corner and
>drool for a while. ;-)
>
>Willard
>  
>


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