prodos-drivers/buhbye.system.s
2017-12-12 20:56:51 -08:00

747 lines
19 KiB
ArmAsm

;;; Disassembly of BYE.SYSTEM (Bird's Better Bye)
;;; Modifications by Joshua Bell inexorabletash@gmail.com
;;; (so this is Bell's Better Bird's Better Bye - Buh-Bye)
;;; * alpha key advances to next matching filename
;;; * replaced directory enumeration (smaller, per PDTRM)
.setcpu "65C02"
.include "apple2.inc"
.include "prodos.inc"
;;; Miscellaneous
COL80HPOS := $57B
;;; I/O Soft Switches / Firmware
RAMRDOFF := $C002 ; If 80STORE Off: Read Main Mem $0200-$BFFF
RAMRDON := $C003 ; If 80STORE Off: Read Aux Mem $0200-$BFFF
RAMWRTOFF := $C004 ; If 80STORE Off: Write Main Mem $0200-$BFFF
RAMWRTON := $C005 ; If 80STORE Off: Write Aux Mem $0200-$BFFF
ALTZPOFF := $C008 ; Main Stack and Zero Page
ALTZPON := $C009 ; Aux Stack and Zero Page
ROMINNW := $C082 ; Read ROM; no write
ROMINWB1 := $C089 ; Read ROM; write RAM bank 1
SLOT3 := $C300
;;; Monitor
SETTXT := $FB39
TABV := $FB5B
SETPWRC := $FB6F
BELL1 := $FBDD
HOME := $FC58
COUT := $FDED
SETINV := $FE80
SETNORM := $FE84
;;; ASCII/Key codes
ASCII_TAB := $9
ASCII_DOWN := $A ; down arrow
ASCII_UP := $B ; up arrow
ASCII_CR := $D
ASCII_RIGHT := $15 ; right arrow
ASCII_SYN := $16 ; scroll text window up
ASCII_ETB := $17 ; scroll text window down
ASCII_EM := $19 ; move cursor to upper left
ASCII_ESCAPE := $1B
;;; ------------------------------------------------------------
.define HI(char) (char|$80)
.macro HIASCII arg
.repeat .strlen(arg), i
.byte .strat(arg, i) | $80
.endrep
.endmacro
.macro HIASCIIZ arg
HIASCII arg
.byte 0
.endmacro
;;; ------------------------------------------------------------
;;; ProDOS Technical Reference Manual, 5.1.5.2:
;;;
;;; ProDOS MLI call $65, the QUIT call, moves addresses $D100 through
;;; $D3FF from the second 4K bank of RAM of the language card to
;;; $1000, and executes a JMP to $1000. What initially resides in that
;;; area is Apple's dispatcher code.
;;; ------------------------------------------------------------
;;; Installer
;;; ------------------------------------------------------------
.org $2000
install_size := $300 ; must fit in $D100...$D3FF = $300
.proc install
src := install_src
end := install_src + install_size
dst := $D100 ; Install location in ProDOS (bank 2)
src_ptr := $19
dst_ptr := $1B
sta ALTZPOFF
lda ROMIN ; write bank 2
lda ROMIN
lda #<src ; src_ptr = src
sta src_ptr
lda #>src
sta src_ptr+1
lda #<dst ; dst_ptr = dst
sta dst_ptr
lda #>dst
sta dst_ptr+1
loop: lda (src_ptr) ; *src_ptr = *dst_ptr
sta (dst_ptr)
inc src_ptr ; src_ptr++
bne :+
inc src_ptr+1
: inc dst_ptr ; dst_ptr++
bne :+
inc dst_ptr+1
: lda src_ptr+1 ; src_ptr == end ?
cmp #>end
bne loop
lda src_ptr
cmp #<end
bne loop
sta ALTZPOFF
sta ROMINWB1
sta ROMINWB1
;; fall through
.endproc
.proc quit
MLI_CALL QUIT, params
.proc params
params: .byte 4
type: .byte 0
res1: .word 0
res2: .byte 0
res3: .addr 0
.endproc
.endproc
install_src := *
;;; ------------------------------------------------------------
;;; Selector
;;; ------------------------------------------------------------
.org $1000
.proc selector
prefix := $280 ; length-prefixed
filenames := $1400 ; each is length + 15 bytes
read_buffer := $2000 ; Also, start location for launched SYS files
;; Device/Prefix enumeration
next_device_num := $65 ; next device number to try
prefix_depth := $6B ; 0 = root
;; Directory enumeration
entry_pointer := $60 ; 2 bytes
block_entries := $62
active_entries := $63 ; 2 bytes
entry_length := $6E
entries_per_block := $6F
file_count := $70 ; 2 bytes
;; Found entries
current_entry := $67 ; index of current entry
num_entries := $68 ; length of |filenames| (max 128)
curr_len := $69 ; length of current entry name
curr_ptr := $6C ; address of current entry name (in |filenames|)
types_table := $74 ; high bit clear = dir, set = sys
;; Entry display
page_start := $73 ; index of first entry shown on screen
row_count := $6A ; number of rows in this page
top_row := 2 ; first row used on screen
bottom_row := 21 ; last row used on screen
;;; ------------------------------------------------------------
cld ; ProDOS protocol for QUIT routine
lda ROMINNW ; Page in ROM for reads, writes ignored
lda #$A0
jsr SLOT3 ; Activate 80-Column Firmware
;; Update system bitmap
ldx #BITMAP_SIZE-1 ; zero it all out
: stz BITMAP,x
dex
bpl :-
inc BITMAP+BITMAP_SIZE-1 ; protect ProDOS global page
lda #%11001111 ; protect zp, stack, text page 1
sta BITMAP
;; Find device
lda DEVCNT ; max device num
sta next_device_num
lda DEVNUM
bne check_device
next_device:
ldx next_device_num
lda DEVLST,x
cpx #1
bcs :+
ldx DEVCNT
inx
: dex
stx next_device_num
check_device:
sta on_line_params_unit
MLI_CALL ON_LINE, on_line_params
bcs next_device
stz prefix_depth
lda prefix+1
and #$0F
beq next_device
adc #2
tax
;; Resize prefix to length x and open the directory for reading
.proc resize_prefix_and_open
stx prefix
lda #'/'
sta prefix+1 ; ensure prefix is at least '/'
sta prefix,x ; and ends with '/'
stz prefix+1,x ; and is null terminated
stz num_entries
;;; Enumerate directory
;;; Algorithm from ProDOS Technical Reference Manual B.2.5
;; Open the directory
jsr do_open
bcc :+
;; Open failed
fail: lda prefix_depth ; root?
beq next_device
jsr pop_prefix ; and go up a level
bra resize_prefix_and_open
;; Open succeeded
: inc prefix_depth
;; Read a block (512 bytes) into buffer
stz read_params_request
lda #2
sta read_params_request+1
jsr do_read
bcs fail
;; Store entry_length (byte), entries_per_block (byte), file_count (word)
ldx #3
: lda read_buffer + DirectoryHeader::entry_length,x
sta entry_length,x
dex
bpl :-
;; Any entries?
lda file_count
ora file_count+1
beq close_dir
;; Skip header entry
clc
lda #<(read_buffer+4) ; 4 bytes for prev/next pointers
adc entry_length
sta entry_pointer
lda #>(read_buffer+4)
adc #0 ; TODO: Can skip this if entry_length << 256
sta entry_pointer+1
;; Prepare to process entry two (first "entry" is header)
lda #2
sta block_entries
while_loop:
;; Check if entry is active
lda (entry_pointer)
beq done_entry
;; Check file type
ldy #FileEntry::file_type
lda (entry_pointer),y
cmp #FileType::Directory
beq store_entry
cmp #FileType::System
bne done_active_entry
store_entry:
;; Store type
ldx num_entries
sta types_table,x
;; Copy name into |filenames|
jsr update_curr_ptr ; current entry in X
ldy #15 ; max name length (length byte copied too)
: lda (entry_pointer),y
sta (curr_ptr),y
dey
bpl :-
iny ; Y = 0; storage_type/name_length in A
and #%00001111 ; mask off name_length (remove storage_type)
sta (curr_ptr),y ; store length
inc num_entries
done_active_entry:
dec file_count
bpl :+
dec file_count+1
:
done_entry:
;; Seen all active entries?
lda file_count
ora file_count+1
beq close_dir
;; Seen all entries in this block?
lda block_entries
cmp entries_per_block
bne next_in_block
;; Grab next block
next_block:
jsr do_read ; read another block
bcs fail
lda #1 ; first entry in non-key block
sta block_entries
lda #<(read_buffer+4) ; 4 bytes for prev/next pointers
sta entry_pointer
lda #>(read_buffer+4)
sta entry_pointer+1
bra end_while
;; Next entry in current block
next_in_block:
clc
lda entry_pointer
adc entry_length
sta entry_pointer
lda entry_pointer+1
adc #0
sta entry_pointer+1
inc block_entries
end_while:
;; Check to see if we have room
bit num_entries ; max is 128
bpl while_loop
close_dir:
MLI_CALL CLOSE, close_params
;; fall through
.endproc
;;; ------------------------------------------------------------
.proc draw_screen
jsr SETTXT ; TEXT
jsr HOME ; HOME
lda #23 ; VTAB 23
jsr TABV
;; Print help text
lda #20 ; HTAB 20
sta CH
ldy #(help_string - text_resources)
jsr cout_string
;; Draw prefix
jsr home
ldx #0
: lda prefix+1,x
beq :+
jsr ascii_cout
inx
bne :-
: stz current_entry
stz page_start
lda num_entries
beq selection_loop_keyboard_loop ; no entries (empty directory)
;; Draw entries
cmp #bottom_row ; more entries than fit?
bcc :+
lda #(bottom_row - top_row + 1)
: sta row_count
lda #top_row
sta WNDTOP
sta WNDLFT
lda #bottom_row+1
sta WNDWDTH
sta WNDBTM
loop: jsr draw_current_line
inc current_entry
dec row_count
bne loop
stz current_entry
beq selection_loop
.endproc
;;; ------------------------------------------------------------
;; Remove level from prefix; returns new length in X
.proc pop_prefix
ldx prefix
loop: dex
lda prefix,x
cmp #'/'
bne loop
cpx #1
bne done
ldx prefix
done:
;; Fall through...
.endproc
handy_rts:
rts
;;; ------------------------------------------------------------
.proc on_down
jsr down_common
bra selection_loop
.endproc
;;; ------------------------------------------------------------
.proc on_up
ldx current_entry ; first one?
beq selection_loop
dec current_entry ; go to previous
lda CV
cmp #top_row ; at the top?
bne selection_loop
dec page_start ; yes, adjust page and
lda #ASCII_SYN ; scroll screen up
jsr COUT
;; fall through
.endproc
;;; ------------------------------------------------------------
.proc selection_loop
jsr SETINV
jsr draw_current_line
keyboard_loop:
lda KBD
bpl keyboard_loop
sta KBDSTRB
jsr SETNORM
cmp #HI(ASCII_TAB)
beq next_drive
cmp #HI(ASCII_ESCAPE)
beq on_escape
ldx num_entries
beq keyboard_loop ; if empty, no navigation
pha
jsr draw_current_line
pla
cmp #HI(ASCII_CR)
beq on_return
cmp #HI(ASCII_DOWN)
beq on_down
cmp #HI(ASCII_UP)
beq on_up
;; fall through
.endproc
selection_loop_keyboard_loop := selection_loop::keyboard_loop
;;; ------------------------------------------------------------
.proc on_alpha
loop: jsr down_common
jsr draw_current_line
lda KBD
and #$5F ; make ASCII and uppercase
ldy #1
cmp (curr_ptr),y ; key = first char ?
beq selection_loop
bra loop
.endproc
;;; ------------------------------------------------------------
.proc on_escape
jsr pop_prefix ; leaves length in X
dec prefix_depth
bra resize_prefix_and_open_jmp
.endproc
;;; ------------------------------------------------------------
.proc down_common
lda current_entry
inc a
cmp num_entries ; past the limit?
bcc :+
pla ; yes - abort subroutine
pla
bra selection_loop
: sta current_entry ; go to next
lda CV
cmp #bottom_row ; at the bottom?
bne handy_rts
inc page_start ; yes, adjust page and
lda #ASCII_ETB ; scroll screen down
jmp COUT ; implicit rts
.endproc
;;; ------------------------------------------------------------
next_drive: ; relay for branches
jmp next_device
inc_resize_prefix_and_open:
inx
resize_prefix_and_open_jmp:
jmp resize_prefix_and_open
;;; ------------------------------------------------------------
.proc on_return
MLI_CALL SET_PREFIX, set_prefix_params
bcs next_drive
ldx current_entry
jsr update_curr_ptr
ldx prefix
: iny
lda (curr_ptr),y
inx
sta prefix,x
cpy curr_len
bcc :-
stx prefix
ldy current_entry
lda types_table,y
bpl inc_resize_prefix_and_open ; is directory???
;; nope, system file, so...
;; fall through
.endproc
;;; ------------------------------------------------------------
.proc launch_sys_file
jsr SETTXT
jsr HOME
lda #HI(ASCII_RIGHT) ; Right arrow ???
jsr COUT
jsr do_open
bcs next_drive
lda #$FF ; Load up to $FFFF bytes
sta read_params_request
sta read_params_request+1
jsr do_read
php
MLI_CALL CLOSE, close_params
plp
bcs next_drive
jmp read_buffer ; Invoke the loaded code
.endproc
;;; ------------------------------------------------------------
.proc cout_string
loop: lda help_string,y
beq handy_rts2
jsr COUT
iny
bra loop
.endproc
;;; ------------------------------------------------------------
;; Compute address/length of curr_ptr/curr_len
;; Call with entry index in X. Returns with Y = 0
.proc update_curr_ptr
stz curr_ptr+1
txa
asl a
rol curr_ptr+1
asl a
rol curr_ptr+1
asl a
rol curr_ptr+1
asl a
rol curr_ptr+1
sta curr_ptr
lda #>filenames
clc
adc curr_ptr+1
sta curr_ptr+1
ldy #0
lda (curr_ptr),y
sta curr_len
;; fall through
.endproc
handy_rts2:
rts
;;; ------------------------------------------------------------
.proc draw_current_line
lda #2 ; hpos = 2
sta COL80HPOS
ldx current_entry ; vpos = entry - page_start + 2
txa
sec
sbc page_start
inc a
inc a
jsr TABV
lda types_table,x
bmi name ; is sys file?
;; Draw folder glyph
stz COL80HPOS
lda INVFLG
pha
ldy #(folder_string - text_resources) ; Draw folder glyphs
jsr cout_string
pla
sta INVFLG
;; Draw the name
name: jsr space
jsr update_curr_ptr
loop: iny
lda (curr_ptr),y
jsr ascii_cout
cpy curr_len
bcc loop
space: lda #HI(' ')
bne cout ; implicit RTS
.endproc
home: lda #HI(ASCII_EM) ; move cursor to top left
;; Sets high bit before calling COUT
ascii_cout:
ora #$80
cout: jmp COUT
;;; ------------------------------------------------------------
.proc do_open
MLI_CALL OPEN, open_params
lda open_params_ref_num
sta read_params_ref_num
rts
.endproc
.proc do_read
MLI_CALL READ, read_params
rts
.endproc
;;; ------------------------------------------------------------
text_resources := *
.proc help_string
HIASCIIZ "RETURN: Select | TAB: Chg Vol | ESC: Back"
.endproc
;; Mousetext sequence: Enable, folder left, folder right, disable
.proc folder_string
.byte $0F,$1B,$D8,$D9,$18,$0E
.byte 0 ; null terminated
.endproc
;;; ------------------------------------------------------------
.proc open_params
params: .byte 3
path: .addr prefix
buffer: .addr $1C00
ref_num:.byte 0
.endproc
open_params_ref_num := open_params::ref_num
.proc close_params
params: .byte 1
ref_num:.byte 0
.endproc
.proc on_line_params
params: .byte 2
unit: .byte $60
buffer: .addr prefix+1
.endproc
on_line_params_unit := on_line_params::unit
.proc set_prefix_params
params: .byte 1
path: .addr prefix
.endproc
.proc read_params
params: .byte 4
ref_num:.byte 1
buffer: .word read_buffer
request:.word 0 ; This can be beyond $12FF - MARKER
trans: .word 0
.endproc
read_params_ref_num := read_params::ref_num
read_params_request := read_params::request
;;; ------------------------------------------------------------
.assert read_params::request - selector <= install_size, error, "Must fit in $300 bytes"
.endproc