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41 lines
767 B
ArmAsm
41 lines
767 B
ArmAsm
; Code from TotalReplay by 4am and qkumba
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;------------------------------------------------------------------------------
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; Has64K
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; Checks whether computer has functioning language card (64K)
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;
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; in: none
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; out: C clear if 64K detected
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; C set if 64K not detected
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; all other flags and registers clobbered
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; ROM in memory (not LC RAM bank)
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;------------------------------------------------------------------------------
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detect_language_card:
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; enable language card
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; READ_RAM1_WRITE_RAM1
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bit $C08B
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bit $C08B
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lda #$AA ; test #1 for $D0 page
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sta $D000
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eor $D000
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bne no_lc
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lsr $D000 ; test #2 for $D0 page
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lda #$55
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eor $D000
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bne no_lc
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clc
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bcc done_detect
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no_lc:
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sec
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done_detect:
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; READ_ROM_NO_WRITE
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bit $C08A
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rts
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