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open-roms/c64/kernal/iostack/f333.clrchn.s
T

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606 B
ArmAsm

// #LAYOUT# STD * #TAKE
// #LAYOUT# * KERNAL_0 #TAKE
// #LAYOUT# * * #IGNORE
//
// Official Kernal routine, described in:
//
// - [RG64] C64 Programmers Reference Guide - page 282
// - [CM64] Computes Mapping the Commodore 64 - page 230
//
// CPU registers that has to be preserved (see [RG64]): .Y
//
CLRCHN:
#if CONFIG_IEC
jsr clrchn_iec
#else
nop // just to prevent double label
#endif
// FALLTROUGH
clrchn_reset: // entry needed by setup_vicii
// Set input device number to keyboard
lda #$00
sta DFLTN
// Set output device number to screen
lda #$03
sta DFLTO
rts