37 lines
814 B
ArmAsm
37 lines
814 B
ArmAsm
|
|
//
|
|
// Official Kernal routine, described in:
|
|
//
|
|
// - [RG64] C64 Programmer's Reference Guide - page 281
|
|
// - [CM64] Compute's Mapping the Commodore 64 - page 230
|
|
//
|
|
// CPU registers that has to be preserved (see [RG64]): .Y
|
|
//
|
|
|
|
|
|
clall_real:
|
|
|
|
// Store .Y register
|
|
phy_trash_a
|
|
|
|
// Original routine probably just sets LDTND to 0, but this is not really safe,
|
|
// so we actually close all the channels; at least IDE64 does the same for
|
|
// it's channels, see CLALL description in the IDE64 User's Guide
|
|
!:
|
|
ldy LDTND
|
|
beq !+
|
|
dey
|
|
lda LAT, y
|
|
jsr JCLOSE
|
|
jmp !-
|
|
!:
|
|
// Restore .Y register
|
|
ply_trash_a
|
|
|
|
// 'C64 Programmers Reference Guide', page 281, claims it calls CLRCHN too
|
|
jsr CLRCHN
|
|
|
|
// Not sure whether original Kernal does so, but it seems sane to also clear possible errors
|
|
jmp kernalstatus_reset
|
|
|