FeralChild64
d489e7bf41
commit 2f27e29758da1f1ec965588c0712125051a6f71a Merge: ba722b1796b62fAuthor: FeralChild64 <you@example.com> Date: Tue Jan 28 17:34:53 2020 +0100 Merge branch 'master' into tape_redirect commit ba722b17e627af7dd067932688de0a3d86423e37 Author: FeralChild64 <you@example.com> Date: Tue Jan 28 17:28:19 2020 +0100 finished Mega65 variant of tape routines commit 47de685f2e08576504c5e00a5b7cb78498d22e72 Author: FeralChild64 <you@example.com> Date: Mon Jan 27 23:06:45 2020 +0100 compilation fix commit c3641acec049a7a6b53c35795b1f9e2df212cec2 Author: FeralChild64 <you@example.com> Date: Mon Jan 27 22:53:30 2020 +0100 dependencies fix commit dfad7a30bde043fa077005624dde1de4b72573b6 Merge: e4b0ec9e410bc0Author: FeralChild64 <you@example.com> Date: Mon Jan 27 21:25:49 2020 +0100 Merge branch 'master' into tape_redirect commit e4b0ec9c85861bde2ce52e0828d3bf895a681e17 Author: FeralChild64 <you@example.com> Date: Sat Jan 25 22:25:20 2020 +0100 initial attempt to move tape code to Mega65 extra ROM
34 lines
817 B
ArmAsm
34 lines
817 B
ArmAsm
// #LAYOUT# STD * #TAKE
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// #LAYOUT# M65 KERNAL_1 #TAKE
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// #LAYOUT# * * #IGNORE
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//
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// Tape helper routine - pulse reading
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//
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// Returns pulse length (with a bias, see comments) in .A
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//
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#if CONFIG_TAPE_NORMAL || CONFIG_TAPE_TURBO
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tape_common_get_pulse:
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// Contrary to original ROM implementation we do not use interrupts
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// (see http://unusedino.de/ec64/technical/formats/tap.html) - busy wait
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// implementation is probably just shorter
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lda #$10
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!:
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bit CIA1_ICR // $DC0D
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beq !- // busy loop to detect signal, restart timer afterwards
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lda CIA2_TIMBLO // $DD06
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ldx #%01010001 // start timer, force latch reload, count timer A underflows
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stx CIA2_CRB // $DD0F
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cmp __pulse_threshold // sdefault pulse check
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rts
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#endif
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