New to group: Intro and a Question
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Posts: 46,084
Scott-
1.8 * 256 = 460 (and change) = 1CC hexadecimal = $01CC
Sounds like you have a handle on the rest. If not, ask some more.
Sure is refreshing to see a question that reflects substantial, prior
effort and study on the part of the questioner. Re the TRS-80, my
Model I is still my favorite and still running fine. I understand
there are computers available now with more speed and memory. But
programming principles haven't changed much.
Welcome to the list/"group". You'll find some good help and good
people here.
Regards,
Steve
1.8 * 256 = 460 (and change) = 1CC hexadecimal = $01CC
Sounds like you have a handle on the rest. If not, ask some more.
Sure is refreshing to see a question that reflects substantial, prior
effort and study on the part of the questioner. Re the TRS-80, my
Model I is still my favorite and still running fine. I understand
there are computers available now with more speed and memory. But
programming principles haven't changed much.
Welcome to the list/"group". You'll find some good help and good
people here.
Regards,
Steve
Comments
My name is Scott and I am new to stamp programming. I recieved my kit a
few days ago and have been very busy learning. I have been lurking here
and reading up on posts. I am realizing I have a lot to learn.
It has been many years since I have done any coding at all...RS TRS-80
days. But it is slowly coming back.
I don't have any specific applications in mind yet for my stamp, It
just looked interesting and I love new challenges.
I'm having some trouble with the */ operator and understanding how it is
used to scale the output of the RC circuit. I think my problem is not
the scaling factor(I understand normalization) but the conversion from
decimal to hex and what is actually happening with the math on the stamp
For example (from Experiment #28 in Stampworks 1.1):
TempIn = TempIn */ $01CC 'multiply by 1.8
How does $01CC = 1.8 ??
To the regulars:
I'm sorry if this is repetitive newbie stuff......If so please point me
in the right direction.
Thanks
Scott
--
***********************************************************************
* "They that will sacrifice liberty in exchange for temporary safety *
* deserve neither liberty or safety." *
*
B. Franklin
*
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http://www.emesystems.com/BS2math1.htm#top
It is much clearer than the Stamp Manual.
Ray McArthur
Original Message
From: Scott <sknutson@l...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, March 28, 2001 3:24 PM
Subject: [noparse][[/noparse]basicstamps] New to group: Intro and a Question
> I'm having some trouble with the */ operator and understanding how it is
> used to scale the output of the RC circuit. I think my problem is not
> the scaling factor(I understand normalization) but the conversion from
> decimal to hex and what is actually happening with the math on the stamp
sknutson@localaccess.com writes:
The */ (star-slash) is a bit tricky at first, but not really that tough. ·The
upper byte is the whole value (1 in the example above) and the lower byte is
the fractional value, expressed in 1/256 increments.
$CC = 204 ... 204 / 256 = 0.796
To go the other way, take your fractional value, multiply it by 256, then
convert to HEX to put it in the form shown above. If you want to multiply by
10.3, for example, you would use $0A4D.
10 --> $0A
0.3 * 256 = 76.8 ... 77 --> $4D
If you go back, the value $0A4D = 10.30078125 (pretty close to 10.3)
There may, at times, be slight rounding errors. ·Tracy Allen has a very good
write-up on this subject if you need a lot of accuracy.
-- Jon Williams
-- Dallas, TX
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