explained all similarities >3, some minor cleanups
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@@ -159,7 +159,7 @@
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.label SAT = $26D // $26D-$276, secondary addresses (table, 10 bytes)
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.label KEYD = $277 // $277-$280, keyboard buffer
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.label MEMSTR = $281 // $281-$282, start of BASIC memory
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.label MEMEND = $283 // $283-$284, NOTE: Mapping the 64 erroneously has the hex as $282 (DEC is correct), name seems to be mistaken too
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.label MEMSIZK = $283 // $283-$284, NOTE: Mapping the 64 erroneously has the hex as $282 (DEC is correct)
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.label TIMOUT = $285 // IEEE-488 timeout
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.label COLOR = $286 // current text foreground color
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.label GDCOL = $287 // color of character under cursor
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+4
-4
@@ -12,13 +12,13 @@ MEMTOP:
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bcc memtop_set
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ldy MEMEND+1
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ldx MEMEND+0
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ldy MEMSIZK+1
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ldx MEMSIZK+0
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rts
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memtop_set:
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sty MEMEND+1
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stx MEMEND+0
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sty MEMSIZK+1
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stx MEMSIZK+0
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rts
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+4
-4
@@ -61,14 +61,14 @@ ramtas_l2:
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ldx #>$0400
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stx HIBASE
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// Work out RAM size and put in MEMSTR and MEMEND
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// Work out RAM size and put in MEMSTR and MEMSIZK
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// "Compute's Mapping the 64", p54
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// http://unusedino.de/ec64/technical/project64/mapping_c64.html
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ldx #>$0800
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stx MEMSTR+1
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ldx #$00
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stx MEMSTR+0
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stx MEMEND+0
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stx MEMSIZK+0
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// Try to modify $8000, if it fails then RAM ends at $7FFF, else $9FFF
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lda $8000
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eor #$FF
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@@ -79,12 +79,12 @@ ramtas_l2:
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beq ramtas_32K_RAM
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sta $8000
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ldx #$A0
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stx MEMEND+1
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stx MEMSIZK+1
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jmp ramtas_RAM_sized
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ramtas_32K_RAM:
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sta $8000 // in case RAM is hiding beneath a ROM
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ldx #$80
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stx MEMEND+1
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stx MEMSIZK+1
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// Fall through
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ramtas_RAM_sized:
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