prodos-drivers/bbb/bye.system.s
2019-10-03 21:15:56 -07:00

724 lines
18 KiB
ArmAsm

;;; Disassembly of BYE.SYSTEM (Bird's Better Bye)
.setcpu "65C02"
.include "apple2.inc"
.include "prodos.inc"
;;; Miscellaneous
RESETVEC := $3F2
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.
;;; ------------------------------------------------------------
;;; Entry point
;;; ------------------------------------------------------------
;; Loads at $2000 but executed at $1000.
.org $2000
jmp install_and_quit
install_src := *
;;; ------------------------------------------------------------
;;; Selector
;;; ------------------------------------------------------------
.org $1000
.proc bbb
prefix := $280 ; length-prefixed
filenames := $1400 ; each is length + 15 bytes
read_buffer := $2000 ; Also, start location for launched SYS files
mark_params := $60
mark_ref_num := $61
mark_position := $62 ; 3-bytes
next_device_num := $65 ; next device number to try
current_entry := $67 ; index of current entry
num_entries := $68 ; length of |filenames|
curr_len := $69 ; length of current entry name
curr_ptr := $6C ; address of current entry name (in |filenames|)
prefix_depth := $6B ; 0 = root
entry_length := $6E
entries_per_block := $6F
file_count := $70 ; 2 bytes
entry_num := $72
page_start := $73 ; index of first entry shown on screen
max_entries := 128 ; max # of entries; more are ignored
types_table := $74 ; high bit clear = dir, set = sys
top_row := 2 ; first row used on screen
bottom_row := 21 ; last row used on screen
;;; ------------------------------------------------------------
cld ; ProDOS protocol for QUIT routine
lda ROMINNW ; Page in ROM for reads, writes ignored
;; Point reset vector at this routine
stz RESETVEC
lda #>bbb
sta RESETVEC+1
jsr SETPWRC ; update validity check byte
lda #$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 #2
sta mark_params
ldx DEVCNT ; max device num
stx 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 #$0F
beq next_device
adc #2
tax
;; Resize prefix to length x and open the directory for reading
.proc resize_prefix_and_open
stx prefix
lda #'/'
sta prefix+1
sta prefix,x
stz prefix+1,x
MLI_CALL OPEN, open_params
bcc :+
;; Open failed
lda prefix_depth ; root?
beq next_device
jsr BELL1 ; no, but failed; beep
jsr pop_prefix ; and go up a level
stx prefix
jmp keyboard_loop
;; Open succeeded
: inc prefix_depth
stz num_entries
lda open_params_ref_num
sta read_params_ref_num
sta mark_ref_num
lda #DirectoryHeader::size
sta read_params_request
stz read_params_request+1
jsr do_read
bcs finish_read2
;; Store entry_length/entries_per_block/file_count
ldx #3
: lda read_buffer + DirectoryHeader::entry_length,x
sta entry_length,x
dex
bpl :-
sta read_params_request
lda #1
sta entry_num
stz mark_position+1
stz mark_position+2
lda file_count
ora file_count+1
bne next_file_entry ; any files?
finish_read2:
bra finish_read
next_file_entry:
bit file_count+1 ; wrap around?
bmi finish_read2
;; TODO: The math here is mysterious; understand and document
floop: lda mark_position+1
and #$FE
sta mark_position+1
ldy entry_num
lda #0
cpy entries_per_block
bcc :+
tay
sty entry_num
inc mark_position+1
carry: inc mark_position+1
: dey
clc
bmi :+
adc entry_length
bcc :-
bcs carry
: adc #4
sta mark_position
MLI_CALL SET_MARK, mark_params
bcs finish_read2
jsr do_read
bcs finish_read2
inc entry_num
lda read_buffer + FileEntry::storage_type
and #$F0 ; mask off storage_type
beq floop ; inactive file entry
dec file_count
bne :+
dec file_count+1
;; Check read access
: ror read_buffer + FileEntry::access
bcc next_file_entry
;; Check file type
lda read_buffer + FileEntry::file_type
cmp #FileType::Directory
beq :+
cmp #FileType::System
bne next_file_entry
;; Check to see if we have room
: ldx num_entries
cpx #max_entries
bcs finish_read
;; Store type
sta types_table,x
;; Copy name
jsr update_curr_ptr
ldy #$0F ; name length + 1 (includes length byte)
: lda read_buffer,y
sta (curr_ptr),y
dey
bpl :-
iny ; Y = 0
and #$0F ; mask off name length (remove storage_type)
sta (curr_ptr),y ; store length
;; Next
inc num_entries
bne next_file_entry
next: jmp next_device
finish_read:
MLI_CALL CLOSE, close_params
bcs next
;; fall through
.endproc
;;; ------------------------------------------------------------
.proc draw_screen
jsr SETTXT ; TEXT
jsr HOME ; HOME
lda #23 ; VTAB 23
jsr TABV
;; Print help text
ldy #0
lda #20 ; HTAB 20
jsr cout_string_hpos
;; 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 keyboard_loop ; no entries (empty directory)
row_count := $6A
cmp #bottom_row ; more entries than fit?
bcc :+
lda #(bottom_row - top_row + 1)
: sta row_count
lda #2
sta WNDTOP
sta WNDLFT
lda #22
sta WNDWDTH
sta WNDBTM
loop: jsr draw_current_line
inc current_entry
dec row_count
bne loop
stz current_entry
beq draw_current_line_inv
.endproc
;;; ------------------------------------------------------------
.proc on_up
jsr draw_current_line ; clear inverse selection
ldx current_entry
beq draw_current_line_inv ; first one? just redraw
dec current_entry ; go to previous
lda CV
cmp #top_row ; at the top?
bne draw_current_line_inv ; if not, just draw
dec page_start ; yes, adjust page and
lda #ASCII_SYN ; scroll screen up
bne draw_current_line_with_char
.endproc
;;; ------------------------------------------------------------
.proc on_down
jsr draw_current_line ; clear inverse selection
ldx current_entry
inx
cpx num_entries ; past the limit?
bcs draw_current_line_inv ; yes, just redraw
stx current_entry ; go to next
lda CV
cmp #bottom_row ; at the bottom?
bne draw_current_line_inv ; if not, just draw
inc page_start ; yes, adjust page and
lda #ASCII_ETB ; scroll screen down
;; fall through
.endproc
;;; ------------------------------------------------------------
draw_current_line_with_char:
jsr COUT
draw_current_line_inv:
jsr SETINV
jsr draw_current_line
;; fall through
;;; ------------------------------------------------------------
.proc keyboard_loop
lda KBD
bpl keyboard_loop
sta KBDSTRB
jsr SETNORM
ldx num_entries
beq :+ ; no up/down/return if empty
cmp #HI(ASCII_CR)
beq on_return
cmp #HI(ASCII_DOWN)
beq on_down
cmp #HI(ASCII_UP)
beq on_up
: cmp #HI(ASCII_TAB)
beq next_drive
cmp #HI(ASCII_ESCAPE)
bne keyboard_loop
;; fall through
.endproc
;;; ------------------------------------------------------------
.proc on_escape
jsr pop_prefix ; leaves length in X
dec prefix_depth
bra resize_prefix_and_open_jmp
.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: rts
.endproc
;;; ------------------------------------------------------------
next_drive:
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
MLI_CALL OPEN, open_params
bcs next_drive
lda open_params_ref_num
sta read_params_ref_num
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
;;; ------------------------------------------------------------
cout_string_hpos:
sta CH
.proc cout_string
loop: lda help_string,y
beq done
jsr COUT
iny
bne loop
done: rts
.endproc
;;; ------------------------------------------------------------
;; Compute address/length of curr_ptr/curr_len
;; Call with entry index in X.
.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
rts
.endproc
;;; ------------------------------------------------------------
.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 - string_start) ; 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
;; fall through
.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_read
MLI_CALL READ, read_params
rts
.endproc
;;; ------------------------------------------------------------
string_start := *
.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
trans: .word 0
.endproc
read_params_ref_num := read_params::ref_num
read_params_request := read_params::request
.assert read_params::request - bbb <= $300, error, "Must fit in $300 bytes"
;;; ------------------------------------------------------------
.res $13FF-*-2, 0
.byte $48,$AD ; 72, 173 ???
.endproc
.assert .sizeof(bbb) = $3FF, error, "Expected size is $3FF"
;;; ------------------------------------------------------------
;;; Installer
;;; ------------------------------------------------------------
.org $2402
.proc install_and_quit
jsr install
MLI_CALL QUIT, params
.proc params
params: .byte 4
type: .byte 0
res1: .word 0
res2: .byte 0
res3: .addr 0
.endproc
.endproc
;;; ------------------------------------------------------------
.proc install
src := install_src
end := install_src + .sizeof(bbb)
dst := $D100 ; Install location in ProDOS (bank 2)
src_ptr := $19
dst_ptr := $1B
sta ALTZPOFF
lda ROMIN
lda ROMIN
lda #>src
sta src_ptr+1
lda #<src
sta src_ptr
lda #>dst
sta dst_ptr+1
lda #<dst
sta dst_ptr
loop: lda (src_ptr)
sta (dst_ptr)
inc src_ptr
bne :+
inc src_ptr+1
: inc dst_ptr
bne :+
inc dst_ptr+1
: lda src_ptr+1
cmp #>end
bne loop
lda src_ptr
cmp #<end
bne loop
lda (src_ptr) ; WTF??
sta (dst_ptr)
sta ALTZPOFF
sta ROMINWB1
sta ROMINWB1
rts
.endproc