[Coco] 6809 CPU architecture

jimcox at miba51.com jimcox at miba51.com
Sat Jan 24 01:45:03 EST 2004


James:

Thank you so much for the insight.  I really appreciate 
it.
I find my self regretting not getting into programming 
sooner.  There is so much to learn.  Thanks again.

Jim

On Fri, 23 Jan 2004 09:50:44 -0500
  jdaggett at gate.net wrote:
>Jim
>
>Pointers are a fundamental entity in programming. The use 
>of the 
>pointer registers are important so that blocks of data or 
>tables can be 
>accessed more easily.
>
>ex:
>
>one has a table of 256 entries of one byte each. You can 
>load the 
>first address of the table in say the X register and then 
>use either the 
>A or B register to index into the table for the item you 
>want. 
>
>Pointers can be used to point data buffers arays. Say you 
>are 
>printing a line of text to a serial port. Accumaltor A 
>can be a 
>character counter to tell you when the line is done and 
>say the X 
>register can be the starting point in memory where the 
>line of data 
>needs to be printed. Register A tells you how many 
>character to print 
>and the X register tells you what to output to the serial 
>port. 
>
>Pointers and the use of the pointer registers is 
>fundamental in any 
>programming language. Even more so in C/C++.
>
>james
>
>
>On 22 Jan 2004 at 22:49, jimcox at miba51.com wrote:
>
>From:           	<jimcox at miba51.com>
>Subject:        	Re: [Coco] 6809 CPU architecture
>To:             	CoCoList for Color Computer Enthusiasts 
><coco at maltedmedia.com>
>Date sent:      	Thu, 22 Jan 2004 22:49:52 -0800
>Send reply to:  	CoCoList for Color Computer Enthusiasts 
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>> On Fri, 23 Jan 2004 00:20:08 -0600
>>   Roger Taylor <rtaylor at bayou.com> wrote:
>> >At 10:17 PM 1/22/2004 -0800, you wrote:
>> >>You're right, that reply was meant for Robert, but I'd 
>> >>also like to thank you for your help too :)
>> >>
>> >>I think I'm missing something, but didn't Robert 
>>already 
>> >>list X, Y, U, amd S?
>> >
>> >
>> >
>> >:)
>> >
>> >Think about it for a minute.
>> >
>> >
>> 
>> Can't think, brain hurts! :)  Hmmm, you listed them as 
>> pointers, maybe that it or maybe I should start reading 
>> one of the many books that I just dug out.  I take it 
>>the 
>> one from Barden is the best (I have about six differnt 
>> ones on 6809 assembly that I either purchased over the 
>> years or were given to me)
>> 
>> Jim
>> 
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>
>
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