[Coco] Extended Color BASIC memory

[Kip Koon]

Allen,
The 6809 machine code in the date statement disassembles as shown in the
following listing.
-------------------------------------
0000: C6 01          ldb        #01
0002: 96 BC          lda        0x00BC
0004: 1F 02           tfr         d,y
0006: 7E 96 A3     jmp      0x96A3
--------------------------------------
AccB is loaded with $01.  
I'll have to check with the variable definitions in the unraveled series to
see what $00BC is but AccA is loaded with the contents of memory location
$00BC.  AccD (AccA+AccB concatenated) is TFR (transferred) to Index Register
Y.
The JMP instruction is jumping back into ECB at address $96A3 with a
parameter of $BC01 in index register Y.  Do I have this right?  My 6809ing
is still quite a bit rusty.
I'm still learning the great commands to include files into and extract
files from RS-DOS disk image files, so I finally just created a text file
with "123456789", changed the extension to "bin" and edited the resulting
file named pclear0.bin with WINHEX changing the contents to the hex bytes
shown in the data statement below.  
I was curious to see what the hex code machine language was doing also, so I
thought I'd find out.  It didn't take me long to do since I had already
compiled 6809dasm.  I used 6809dasm compiled and run in CYGWIN to get the
resulting disassembly listing.
Hope this helps.  Have fun!
Kip

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
Behalf Of Allen Huffman
Subject: [Coco] Extended Color BASIC memory

<portions deleted>

5
FORA=0TO8:READA$:POKE1024+A,VAL("&H"+A$):NEXTA:EXEC1024:DATAC6,1,96,BC,1F,2,
7E,96,A3

So... Someone wanna re-remind me what this actually does to accomplish
PCLEAR 0?

-
Allen Huffman - PO Box 22031 - Clive IA 50325 - 515-999-0227 (vmail/TXT
only) Sent from my iPad.

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