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| author | B. Watson <yalhcru@gmail.com> | 2016-01-06 04:04:57 -0500 |
|---|---|---|
| committer | B. Watson <yalhcru@gmail.com> | 2016-01-06 04:04:57 -0500 |
| commit | d90c75703d7a9ca53fded2a40fa35344279ed843 (patch) | |
| tree | dd88251aa2aa4c2f5d67abb40c263d7427915bbf /comptitle.s.in | |
| parent | ad615f1eb4febb59f5148ba356d9ad91dc72db09 (diff) | |
| download | taipan-d90c75703d7a9ca53fded2a40fa35344279ed843.tar.gz | |
document the compression before I forget
Diffstat (limited to 'comptitle.s.in')
| -rw-r--r-- | comptitle.s.in | 43 |
1 files changed, 26 insertions, 17 deletions
diff --git a/comptitle.s.in b/comptitle.s.in index 7862b3d..b8ed688 100644 --- a/comptitle.s.in +++ b/comptitle.s.in @@ -1,3 +1,4 @@ +;;; see titlecompression.txt to understand how this works! ; cl65 -o comptitle.xex -t none comptitle.s @@ -37,6 +38,13 @@ table: ; decompression code starts here init: + lda #0 + + ;;; for benchmarking only, remove! + ;sta RTCLOK + ;sta RTCLOK+1 + ;sta RTCLOK+2 + lda #>imgsize sta pagecount lda #>compdata @@ -62,7 +70,22 @@ copyloop: beq notcode ; got a zero-run code. A = number of bytes of zeroes to store. - jmp storezerorun +storezerorun: + sty tmp + tay + dey + lda #0 +szloop: + sta (dstptr),y + jsr incdest + beq done +nohi2: + dey + bpl szloop + + ldy tmp + clc + bcc storedone notcode: lda tmp @@ -83,24 +106,10 @@ storedone: bne copyloop ; always branch (since srcptr never wraps around to 0) done: + ;;; for benchmarking only, remove! + ;.byte $02 ; CIM, drops us to atari800 monitor rts -storezerorun: - sty tmp - tay - dey - lda #0 -szloop: - sta (dstptr),y - jsr incdest - beq done -nohi2: - dey - bpl szloop - - ldy tmp - jmp storedone - incdest: inc dstptr bne iddone |