65 lines
1.6 KiB
ArmAsm
65 lines
1.6 KiB
ArmAsm
|
|
//
|
|
// Official Kernal routine, described in:
|
|
//
|
|
// - [RG64] C64 Programmer's Reference Guide - page 281/282
|
|
// - [CM64] Compute's Mapping the Commodore 64 - page 229/230
|
|
// - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc (IEC command)
|
|
//
|
|
// CPU registers that has to be preserved (see [RG64]): none
|
|
//
|
|
|
|
CLOSE:
|
|
|
|
// XXX this needs more testing (opening 10 files at once, closing in various orders, etc) once the code is more mature
|
|
|
|
// Find the LAT / SAT / FAT entry which LAT corresponds to A
|
|
|
|
jsr find_fls
|
|
bcs close_error_not_found // XXX can we report error in IOSTATUS here?
|
|
|
|
// We have the entry index in Y - check whether this is IEC device
|
|
lda FAT, y
|
|
jsr iec_check_devnum
|
|
bcs close_remove_from_table
|
|
|
|
// IEC device
|
|
|
|
jsr iec_tx_flush // make sure no byte is awaiting
|
|
lda SAT, y // get secondary address
|
|
cmp #$60
|
|
bne !+
|
|
// workaround for using CLOSE on reading executable - XXX is this a proper way?
|
|
jsr close_load
|
|
jmp close_remove_from_table
|
|
!:
|
|
ora $E0 // CLOSE command
|
|
sta TBTCNT
|
|
jsr iec_tx_command
|
|
bcs close_remove_from_table
|
|
jsr iec_tx_command_finalize
|
|
|
|
close_remove_from_table:
|
|
// Remove channel from the table
|
|
iny
|
|
cpy #$0A
|
|
bpl !+
|
|
lda LAT, y
|
|
sta LAT-1, y
|
|
lda FAT, y
|
|
sta FAT-1, y
|
|
lda SAT, y
|
|
sta SAT-1, y
|
|
jmp close_remove_from_table
|
|
!:
|
|
// Decrement the list size variable
|
|
dec LDTND
|
|
|
|
clc // report success - not sure if original CLOSE does this, but it's nevertheless a good practice
|
|
rts
|
|
|
|
close_error_not_found:
|
|
|
|
sec // report success - not sure if original CLOSE does this, but it's nevertheless a good practice
|
|
rts
|