roms/boot.s - minecraft/thistle - Rivoreo Source Code Repositories

 ;
 ; Thistle Boot ROM
 ;
 	.setcpu		"65c02"

 .segment	"STARTUP"

 .byte "--[[CABE:Thistle:"

 .segment "RODATA"

 ; TSF Component Data
 fslist: .byte 10,10,0,"filesystem",0
 umlist: .byte 10,5,0,"drive",0
 secread: .byte 10,10,0,"readSector",3,1,0
 fsopend: .byte 10,4,0,"open",10,12,0,"Thistle/boot",0
 fsopenf: .byte 10,4,0,"open",10,7,0,"Thistle",0
 fsclose: .byte 10,5,0,"close"
 fsread: .byte 10,4,0,"read",14,0,0,0,0,4,0,1,0

 ; Messages
 greeting: .byte "Thistle Boot ROM",10,10
 nomem: .byte "No Memory installed"
 drives: .byte "Checking drives ...",10
 fsmsg: .byte 10,"Checking filesystems ...",10
 bootmsg: .byte "Booting ...",10
 noboot: .byte "Nothing to boot from",10

 hexlookup: .byte "0123456789abcdef"

 unkcmd: .byte "Unknown Command",10

 cmdlist:
 .asciiz "ls"
 .word cmd_ls
 .asciiz "list"
 .word cmd_list
 .asciiz "load"
 .word cmd_load
 .asciiz "save"
 .word cmd_save
 .asciiz "run"
 .word cmd_run
 .asciiz ""

 .define inval $FF

 opcodetbl:
 .byte "BRK",$07,"ORA",$09,inval,$00,inval,$07,"TSB",$01,"ORA",$01,"ASL",$01,"RB0",$01,"PHP",$07,"ORA",$00,"ASL",$07,inval,$07,"TSB",$04,"ORA",$04,"ASL",$04,"BR0",$0E
 .byte "BPL",$08,"ORA",$0A,"ORA",$0D,inval,$07,"TRB",$01,"ORA",$02,"ASL",$02,"RB1",$01,"CLC",$07,"ORA",$06,"INC",$07,inval,$07,"TRB",$04,"ORA",$05,"ASL",$05,"BR1",$0E
 .byte "JSR",$04,"AND",$09,inval,$00,inval,$07,"BIT",$01,"AND",$01,"ROL",$01,"RB2",$01,"PLP",$07,"AND",$00,"ROL",$07,inval,$07,"BIT",$04,"AND",$04,"ROL",$04,"BR2",$0E
 .byte "BMI",$08,"AND",$0A,"AND",$0D,inval,$07,"BIT",$02,"AND",$02,"ROL",$02,"RB3",$01,"SEC",$07,"AND",$06,"DEC",$07,inval,$07,"BIT",$05,"AND",$05,"ROL",$05,"BR3",$0E
 .byte "RTI",$07,"EOR",$09,inval,$00,inval,$07,inval,$01,"EOR",$01,"LSR",$01,"RB4",$01,"PHA",$07,"EOR",$00,"LSR",$07,inval,$07,"JMP",$04,"EOR",$04,"LSR",$04,"BR4",$0E
 .byte "BVC",$08,"EOR",$0A,"EOR",$0D,inval,$07,inval,$02,"EOR",$02,"LSR",$02,"RB5",$01,"CLI",$07,"EOR",$06,"PHY",$07,inval,$07,inval,$04,"EOR",$05,"LSR",$05,"BR5",$0E
 .byte "RTS",$07,"ADC",$09,inval,$00,inval,$07,"STZ",$01,"ADC",$01,"ROR",$01,"RB6",$01,"PLA",$07,"ADC",$00,"ROR",$07,inval,$07,"JMP",$0B,"ADC",$04,"ROR",$04,"BR6",$0E
 .byte "BVS",$08,"ADC",$0A,"ADC",$0D,inval,$07,"STZ",$02,"ADC",$02,"ROR",$02,"RB7",$01,"SEI",$07,"ADC",$06,"PLY",$07,inval,$07,"JMP",$0C,"ADC",$05,"ROR",$05,"BR7",$0E
 .byte "BRA",$08,"STA",$09,inval,$00,inval,$07,"STY",$01,"STA",$01,"STX",$01,"SB0",$01,"DEY",$07,"BIT",$00,"TXA",$07,inval,$07,"STY",$04,"STA",$04,"STX",$04,"BS0",$0E
 .byte "BCC",$08,"STA",$0A,"STA",$0D,inval,$07,"STY",$02,"STA",$02,"STX",$03,"SB1",$01,"TYA",$07,"STA",$06,"TXS",$07,inval,$07,"STZ",$04,"STA",$05,"STZ",$05,"BS1",$0E
 .byte "LDY",$00,"LDA",$09,"LDX",$00,inval,$07,"LDY",$01,"LDA",$01,"LDX",$01,"SB2",$01,"TAY",$07,"LDA",$00,"TAX",$07,inval,$07,"LDY",$04,"LDA",$04,"LDX",$04,"BS2",$0E
 .byte "BCS",$08,"LDA",$0A,"LDA",$0D,inval,$07,"LDY",$02,"LDA",$02,"LDX",$03,"SB3",$01,"CLV",$07,"LDA",$06,"TSX",$07,inval,$07,"LDY",$05,"LDA",$05,"LDX",$06,"BS3",$0E
 .byte "CPY",$00,"CMP",$09,inval,$00,inval,$07,"CPY",$01,"CMP",$01,"DEC",$01,"SB4",$01,"INY",$07,"CMP",$00,"DEX",$07,"WAI",$07,"CPY",$04,"CMP",$04,"DEC",$04,"BS4",$0E
 .byte "BNE",$08,"CMP",$0A,"CMP",$0D,inval,$07,inval,$02,"CMP",$02,"DEC",$02,"SB5",$01,"CLD",$07,"CMP",$06,"PHX",$07,"STP",$07,inval,$04,"CMP",$05,"DEC",$05,"BS5",$0E
 .byte "CPX",$00,"SBC",$09,inval,$00,inval,$07,"CPX",$01,"SBC",$01,"INC",$01,"SB6",$01,"INX",$07,"SBC",$00,"NOP",$07,inval,$07,"CPX",$04,"SBC",$04,"INC",$04,"BS6",$0E
 .byte "BEQ",$08,"SBC",$0A,"SBC",$0D,inval,$07,inval,$02,"SBC",$02,"INC",$02,"SB7",$01,"SED",$07,"SBC",$06,"PLX",$07,inval,$07,inval,$04,"SBC",$05,"INC",$05,"BS7",$0E

 length: .byte 2,2,2,2,3,3,3,1,2,2,2,3,3,2,3

 format:
 .byte "#$__",$00,$00
 .byte "#'_'",$00,$00
 .byte "$__",$00,$01
 .byte "$__,X",$00,$02
 .byte "$__,Y",$00,$03
 .byte "$____",$00,$04
 .byte "$____,X",$00,$05
 .byte "$____,Y",$00,$06
 .byte "0X__",$00,$08
 .byte "-0X__",$00,$08
 .byte "($__,X)",$00,$09
 .byte "($__),Y",$00,$0a
 .byte "($____)",$00,$0b
 .byte "($____,X)",$00,$0c
 .byte "($__)",$00,$0d
 .byte "$__,0X__",$00,$0e
 .byte "$__,-0X__",$00,$0e
 .byte $00,$07 ; Must be last

 .segment "STARTUP"

 .define inputlen $80
 .define good $81
 .define formattype $82
 .define addrmode $83
 .define opcode $84
 .define indlow $85
 .define indhigh $86
 .define curlow $87
 .define curhigh $88

 .macro dmacopy src, dest, len, mode
 	.ifnblank src
 		.if .const(src) .and .lobyte(src) = 0
 			stz $E041
 		.else
 			lda #<src
 			sta $E041
 		.endif
 		.if .const(src) .and .hibyte(src) = 0
 			stz $E042
 		.else
 			lda #>src
 			sta $E042
 		.endif
 	.endif
 	.ifnblank dest
 		.if .const(dest) .and .lobyte(dest) = 0
 			stz $E043
 		.else
 			lda #<dest
 			sta $E043
 		.endif
 		.if .const(dest) .and .hibyte(dest) = 0
 			stz $E044
 		.else
 			lda #>dest
 			sta $E044
 		.endif
 	.endif
 	.ifnblank len
 		.if .const(len) .and len = 0
 			stz $E045
 		.else
 			lda #<len
 			sta $E045
 		.endif
 	.endif
 	.if .const(mode) .and mode = 0
 		stz $E040
 	.else
 		lda #mode
 		sta $E040
 	.endif
 .endmacro

 .macro dmaload src, dest, len
 	.ifnblank src
 		.if .const(src) .and .lobyte(src) = 0
 			stz $E041
 		.else
 			lda #<src
 			sta $E041
 		.endif
 		.if .const(src) .and .hibyte(src) = 0
 			stz $E042
 		.else
 			lda #>src
 			sta $E042
 		.endif
 	.endif
 	.ifnblank dest
 		.if .const(dest) .and .lobyte(dest) = 0
 			stz $E043
 		.else
 			lda #<dest
 			sta $E043
 		.endif
 		.if .const(dest) .and .hibyte(dest) = 0
 			stz $E044
 		.else
 			lda #>dest
 			sta $E044
 		.endif
 	.endif
 	.ifnblank len
 		.if .const(len) .and len = 0
 			stz $E045
 		.else
 			lda #<len
 			sta $E045
 		.endif
 	.endif
 .endmacro

 .define mode_pp $00
 .define mode_pu $01
 .define mode_up $02
 .define mode_uu $03

 hexprint:
 	; Prints a byte to the screen
 	; A - byte to print
 	; Clobbers: X
 	pha
 	phy
 	tax
 	lsr
 	lsr
 	lsr
 	lsr
 	tay
 	lda hexlookup,Y
 	sta $E003
 	txa
 	and #$0F
 	tay
 	lda hexlookup,Y
 	sta $E003
 	ply
 	pla
 	rts

 uuidprint:
 	; Prints a UUID to the screen
 	; $00, $01 - Address of UUID
 	; Clobbers: A, X (hexprint), Y
 	ldy #$00
 @loop:
 	lda (indlow),Y
 	jsr hexprint
 	iny
 	cpy #$10
 	beq @done
 	cpy #$04
 	beq @dash
 	cpy #$06
 	beq @dash
 	cpy #$08
 	beq @dash
 	cpy #$0A
 	beq @dash
 	bra @loop
 @dash:
 	lda #$2D
 	sta $E003
 	bra @loop
 @done:
 	lda #$0a
 	sta $E003
 	rts

 _readlist:
 	; Reads component list to $0200
 	; $02 - Bytes to skip for component type
 	; Clobbers: A, X, Y, indlow, indhigh
 	lda $E011
 	sta $03
 	stz indlow
 	ldy #$00
 	lda #$02
 	sta indhigh
 @loop1:
 	lda $E012
 	cmp #$00 ; TSF End Tag
 	beq @done

 	; Read UUID
 	ldx #$10
 @loop2:
 	lda $E012
 	sta (indlow),Y
 	jsr inc_y
 	dex
 	cpx #$00
 	bne @loop2

 	; Drop component name
 	ldx $02
 @loop3:
 	lda $E012
 	dex
 	cpx #$00
 	bne @loop3
 	bra @loop1
 @done:
 	lda #$02
 	sta indhigh
 	rts

 .macro readlist skip
 	lda #skip
 	sta $02
 	jsr _readlist
 .endmacro

 loaduuid:
 	; Load a UUID into the component selector buffer
 	; indlow, indhigh - Address to read from
 	; Clobbers: A, X, Y, (uuidprint)
 	jsr uuidprint
 loaduuid2:
 	ldy indlow
 	stz indlow
 	ldx #$10
 	lda #$0b ; UUID Tag
 	sta $E012
 @loop:
 	lda (indlow),Y ; UUID Byte loop
 	sta $E012
 	jsr inc_y
 	dex
 	cpx #$00
 	bne @loop
 	sty indlow
 	stz $E012 ; End Tag
 	stz $E010 ; Map Component
 	rts

 closehandle:
 	; Closes an open file handle
 	; $08-$0C - Handle to close
 	; Clobbers: A
 	dmacopy fsclose, $D001, .sizeof(fsclose), mode_up ; Call close
 	dmacopy $0008, , 5, mode_up ; ($0008, $D001, 5, mode_up)
 	stz $D001
 	stz $D000
 	dmacopy , $E012, , mode_up ; ($0008, $E012, 5, mode_up) Destroy value
 	stz $E012
 	lda #$04
 	sta $E010
 	rts

 loadfile:
 	; Reads a file into memory starting at $0200
 	stz curlow
 	lda #$02
 	sta curhigh
 	dmacopy fsread, $0001, .sizeof(fsread), mode_uu ; Copy read command
 	dmacopy $D001, $0008, 5, mode_pu ; Inject handle
 @loop:
 	ldx curhigh
 	cpx #$D0
 	beq @done ; Too much data read
 	dmacopy $0001, $D001, .sizeof(fsread), mode_up ; Call "read"
 	stz $D000

 	lda $D001 ; Check TSF Tag
 	cmp #$09 ; Byte array?
 	beq :+
 	cmp #$0A ; String?
 	bne @done ; No more data to read

 :	lda $D001 ; Read length
 	sta indlow
 	lda $D001
 	sta indhigh
 	ldy #$01 ; Setup Copy Engine
 	sty $E041
 	lda #$D0
 	sta $E042
 	clc ; Load address and add at same time
 	lda curlow
 	sta $E043
 	adc indlow
 	sta curlow
 	lda curhigh
 	sta $E044
 	adc indhigh
 	sta curhigh
 	lda indlow
 	sta $E045
 	lda indhigh
 	sta $E046
 	sty $E040 ; Execute Copy Engine Command
 	bra @loop
 @done:
 	stz $E046 ; Put high byte of size back to 0
 	jsr closehandle
 	rts

 dispboot:
 	dmacopy bootmsg, $E003, .sizeof(bootmsg), mode_up
 	rts

 bootdrive:
 	; Checks and boots from a drive
 	lda $D000
 	cmp #$00
 	beq :+
 	rts
 :	jsr dispboot
 	pla ; Remove address from stack
 	pla ; We're not returning to havemem
 	lda #$01 ; Setup Copy Engine
 	sta $E041
 	lda #$D0
 	sta $E042
 	stz $E043
 	lda #$02
 	sta $E044

 	lda $D001 ; Discard tag
 	lda $D001
 	sta $E045
 	lda $D001
 	sta $E046

 	lda #mode_pu ; Copy
 	sta $E040

 	stz $E046
 	jsr $0200 ; Boot
 	jmp fschk

 bootfs:
 	; Boots from a file
 	lda $D000
 	cmp #$00
 	beq :+
 	rts ; No file opened
 :	jsr dispboot
 	pla ; Remove address from stack
 	pla ; We're not returning to fschk
 	jsr loadfile
 	jsr $0200 ; Boot
 	jmp commands

 reset:
 	; Display boot greeting
 	dmacopy greeting, $E003, .sizeof(greeting), mode_up

 	; Memory Check
 	lda $E018
 	cmp #$00
 	bne havemem
 	lda $E019
 	cmp #$00
 	bne havemem
 	; No Memory Installed
 	dmacopy nomem, , .sizeof(nomem), mode_up ; (nomem, $E003, .sizeof(nomem), mode_up)
 @loop:	bra @loop

 havemem:
 	dmacopy drives, , .sizeof(drives), mode_up ; (drives, $E003, .sizeof(drives), mode_up)
 	; Look for "drive" components
 	dmacopy umlist, $E012, .sizeof(umlist), mode_up
 	lda #$03
 	sta $E010
 	readlist 8 ; Store list to memory

 	; Parse list
 @loop:
 	lda $03
 	cmp #$00
 	beq fschk ; No "drive" componets left to check
 	jsr loaduuid
 	dmacopy secread, $D001, .sizeof(secread), mode_up ; Call readSector
 	stz $D000
 	jsr bootdrive
 	dec $03
 	bra @loop

 fschk:
 	dmacopy fsmsg, $E003, .sizeof(fsmsg), mode_up
 	; Look for "filesystem" components
 	dmacopy fslist, $E012, .sizeof(fslist), mode_up
 	lda #$03
 	sta $E010
 	readlist 13 ; Store list to memory

 	; Parse list
 @loop:
 	lda $03
 	cmp #$00
 	bne :+
 	jmp failboot ; No "filesystem" componets left to check
 :	jsr loaduuid
 	dmaload , $D001
 	dmacopy fsopend, , .sizeof(fsopend), mode_up ; (fsopend, $D001, .sizeof(fsopend), mode_up) open Thistle/boot
 	stz $D000
 	jsr bootfs
 	dmacopy fsopenf, , .sizeof(fsopenf), mode_up ; (fsopenf, $D001, .sizeof(fsopenf), mode_up) open Thistle
 	stz $D000
 	jsr bootfs
 	dec $03
 	bra @loop

 hex2val:
 	; Converts two hexadecimal characters to a value
 	lda $00,X
 	clc
 	sbc #$2f
 	cmp #$11
 	bcc :+
 	clc
 	sbc #$06
 :	sta good
 	dex
 	lda $00,X
 	clc
 	sbc #$2f
 	cmp #$11
 	bcc :+
 	clc
 	sbc #$06
 :	asl
 	asl
 	asl
 	asl
 	eor good
 	dex
 	sta (curlow),Y
 	iny
 	rts

 inc_y:
 	; Handle page wraps
 	iny
 	cpy #$00
 	bne :+
 	inc indhigh
 :	rts

 failboot:
 	dmacopy noboot, $E003, .sizeof(noboot), mode_up

 	; Try to select a non tmpfs filesystem
 	dmacopy fslist, $E012, .sizeof(fslist), mode_up
 	lda #$03
 	sta $E010
 	readlist 13 ; Store list to memory

 @loop:
 	lda $03
 	cmp #$00
 	beq commands
 	ldx #$00
 	ldy #$00
 	stz good
 @loop2:
 	lda (indlow),Y
 	cmp $E110,X
 	beq :+
 	sty good
 	lda indlow
 	clc
 	adc good
 	stx good
 	sec
 	sbc indlow
 	sta indlow
 	jsr loaduuid2
 	bra commands
 :	inx
 	jsr inc_y
 	cpx #$10
 	bne @loop2
 	ldx #$00
 	dec $03
 	bra @loop

 commands:
 	stz $E001 ; Drop all input
 	stz curlow
 	lda #$02
 	sta curhigh
 @setup:	lda #'$'
 	sta $E003
 	lda curhigh
 	jsr hexprint
 	lda curlow
 	jsr hexprint
 	ldx #' '
 	stx $E003
 	lda #'>'
 	sta $E003
 	stx $E003
 	stz inputlen
 @loop:	lda $E000
 	cmp #$00
 	beq @loop ; No Input
 	ldx inputlen
 	lda $E001
 	cmp #$00 ; Scancode, discard
 	bne :+
 	lda $E001
 	bra @loop
 :	cmp #$08 ; Backspace
 	bne :+
 	cpx #$00
 	beq @loop ; No input to delete
 	sta $E003
 	dec inputlen
 	bra @loop
 :	cmp #$0A ; Enter
 	beq @exec
 	cpx #$80 ; Character
 	beq @loop
 	sta $E003
 	sta $00,X
 	inc inputlen
 	bra @loop
 @exec:
 	sta $E003
 	cpx #$00 ; No Input
 	beq @setup
 	; @setup for comparing cmd names
 	lda #<cmdlist
 	sta indlow
 	lda #>cmdlist
 	sta indhigh
 	ldx #$00
 	ldy #$00
 	stz good
 	; Compare against cmd list
 @ncloop:
 	lda (indlow),Y
 	cmp #$00 ; NUL, end of cmd name
 	beq @nccheck
 	cmp $00,X ; Matches
 	beq :+
 	smb0 good ; Mark as bad
 :	inx
 	jsr inc_y
 	bra @ncloop
 @nccheck:
 	jsr inc_y
 	cpx #$00 ; No more cmd entries?
 	beq @asm
 	cmp good ; A = $00
 	bne @ncbad
 	cpx inputlen
 	beq @ncfound
 	lda $00,X
 	cmp #' '
 	beq @ncfound
 @ncbad:
 	stz good ; Did not match, reset
 	ldx #$00
 	jsr inc_y ; Skip over address
 	jsr inc_y
 	bra @ncloop
 @ncfound:
 	lda #$4C ; JMP $XXXX
 	sta opcode
 	lda (indlow),Y
 	tax
 	jsr inc_y
 	lda (indlow),Y
 	stx indlow
 	sta indhigh
 	jsr opcode
 	jmp @setup
 @asm:
 	; Assembly code!
 	; Uppercase it all
 	ldx #$00
 @ucloop:
 	lda $00,X
 	clc
 	sbc #$60
 	bmi :+
 	adc #$40
 	sta $00,X
 :	inx
 	cpx inputlen
 	bne @ucloop
 	; Setup for comparing format strings
 	ldx #$04
 	ldy #$00
 	stz formattype
 	stz good
 	lda inputlen
 	cmp #$03 ; Three characters?
 	bcs :+
 	jmp @badcmd
 :	beq @amloop
 	lda $03
 	cmp #$20
 	beq @amloop
 	jmp @badcmd ; 4th character not a space
 	; Identify addressing mode
 @amloop:
 	lda format,Y
 	cmp #$00 ; NUL, end of format string
 	beq @amcheck
 	cmp #$5F ; Underscore
 	beq :+
 	cmp $00,X ; Matches
 	beq :+
 	smb0 good ; Mark as bad
 :	inx
 	iny
 	bra @amloop
 @amcheck:
 	iny
 	cpx #$04 ; No more format entries?
 	beq @amfound ; Assume implied
 	cmp good ; A = $00
 	bne @ambad
 	cpx inputlen
 	beq @amfound
 	bcs @ambad ; Not enough imput
 	lda $00,X
 	cmp #' '
 	beq @amfound
 @ambad:
 	stz good ; Wrong addressing mode, reset
 	ldx #$04
 	iny
 	inc formattype
 	bra @amloop
 @amfound:
 	lda format,Y
 	sta addrmode
 	lda #<opcodetbl
 	sta indlow
 	lda #>opcodetbl
 	sta indhigh
 	ldy #$00
 	ldx #$00
 	stz opcode
 	stz good
 	; Compare opcode names
 @oploop:
 	lda (indlow),Y
 	cmp $00,X
 	beq :+
 	smb0 good ; Mark as bad
 :	inx
 	jsr inc_y
 	cpx #$03
 	beq @opcheck
 	cmp #$FF
 	beq @opcheck
 	bra @oploop
 @opcheck:
 	lda (indlow),Y
 	cmp addrmode
 	beq :+
 	smb0 good ; Mark as bad
 :	lda #$00
 	cmp good
 	beq @opfound

 	stz good ; Wrong opcode, reset
 	ldx #$00
 	jsr inc_y
 	inc opcode
 	lda opcode
 	cmp #$00 ; Wrapped back to 0
 	bne :+
 	jmp @badcmd
 :	bra @oploop
 @opfound:
 	ldy #$00
 	lda opcode
 	sta (curlow),Y ; Write opcode to memory
 	iny
 	lda formattype
 	cmp #$00 ; immediate
 	beq @read21
 	cmp #$01 ; immediate w/ character
 	beq @readchar
 	cmp #$02 ; zeropage
 	beq @read20
 	cmp #$03 ; zp indexed x
 	beq @read20
 	cmp #$04 ; zp indexed y
 	beq @read20
 	cmp #$05 ; absolute
 	beq @read40
 	cmp #$06 ; indexed x
 	beq @read40
 	cmp #$07 ; indexed y
 	beq @read40
 	cmp #$08 ; relative
 	beq @read21
 	cmp #$09 ; relative w/ minus
 	beq @relminus
 	cmp #$0a ; zp indirect x
 	beq @read21
 	cmp #$0b ; zp indirect y
 	beq @read21
 	cmp #$0c ; indirect
 	beq @read41
 	cmp #$0d ; indirect x
 	beq @read41
 	cmp #$0e ; zp indirect
 	beq @read21
 	cmp #$0f ; zp relative
 	beq @readzpr
 	cmp #$10 ; zp relative minus
 	beq @zprminus
 	bra @opskip
 @readchar:
 	ldx #$06
 	lda $00,X
 	sta (curlow),Y
 	bra @opskip
 @read20:
 	ldx #$06
 	jsr hex2val
 	bra @opskip
 @read21:
 	ldx #$07
 	jsr hex2val
 	bra @opskip
 @read40:
 	ldx #$08
 	jsr hex2val
 	jsr hex2val
 	bra @opskip
 @read41:
 	ldx #$09
 	jsr hex2val
 	jsr hex2val
 	bra @opskip
 @readzpr:
 	ldx #$06
 	jsr hex2val
 	ldx #$0b
 	jsr hex2val
 	bra @opskip
 @zprminus:
 	ldx #$06
 	jsr hex2val
 	ldx #$0c
 	bra :+
 @relminus:
 	ldx #$08
 :	jsr hex2val
 	dey
 	sec
 	lda #$00
 	sbc (curlow),Y
 	sta (curlow),Y
 @opskip:
 	ldy addrmode
 	ldx length,Y
 	ldy curlow
 @incloop:
 	iny
 	cpy #$00
 	bne :+
 	inc curhigh
 :	dex
 	cpx #$00
 	bne @incloop
 	sty curlow
 	bra :+
 @badcmd:
 	dmacopy unkcmd, $E003, .sizeof(unkcmd), mode_up ; (unkcmd, $E003, .sizeof(unkcmd), mode_up)
 :	jmp @setup

 loadinput:
 	; Loads string from input buffer into Component 1
 	lda inputlen
 	cmp good
 	bcs :+
 	lda good
 :	clc
 	sbc good
 	inc
 	sta $D001
 	sta $E045 ; Copy Engine Length
 	stz $D001

 	lda good ; Setup Copy Engine
 	sta $E041
 	stz $E042
 	lda #$01
 	sta $E043
 	lda #$D0
 	sta $E044
 	lda #mode_up ; Copy
 	sta $E040
 	rts

 .segment "RODATA"

 listtest: .byte 10,4,0,"list",10
 listfail: .byte "Listing failed",10

 .segment "STARTUP"

 cmd_ls:
 	lda #$03 ; inputlen
 	sta good
 	bra :+
 cmd_list:
 	lda #$05 ; inputlen
 	sta good
 :	dmacopy listtest, $D001, .sizeof(listtest), mode_up
 	jsr loadinput
 	stz $D001 ; TSF End Tag
 	stz $D000 ; Invoke
 	lda $D000
 	cmp #$00
 	beq :+
 	dmacopy listfail, $E003, .sizeof(listfail), mode_up
 	rts
 :	lda $D001 ; Drop Array Tag
 @loop:
 	lda $D001
 	cmp #$00 ; TSF End Tag
 	beq @done
 	ldy $D001 ; Length low
 	ldx $D001 ; Length high
 @readloop:
 	cpy #$00
 	bne :+
 	cpx #$00
 	bne :+
 	lda #$0A
 	sta $E003
 	bra @loop
 :	lda $D001
 	sta $E003
 	dey
 	cpy #$FF
 	bne :+
 	dex
 :	bra @readloop
 @done:
 	rts

 .segment "RODATA"

 openfail: .byte "Could not open file",10
 loadmsg: .byte "Loading file ...",10

 .segment "STARTUP"

 cmd_load:
 	lda inputlen
 	cmp #$06
 	bcs :+
 	rts
 :	dmacopy fsopenf, $D001, 8, mode_up ; Copy 10,4,0,"open",10
 	lda #$05 ; inputlen
 	sta good
 	jsr loadinput
 	stz $D001 ; TSF End Tag
 	stz $D000 ; Invoke
 	lda $D000
 	cmp #$00
 	beq :+
 	dmacopy openfail, $E003, .sizeof(openfail), mode_up ; No file opened
 	rts
 :	dmacopy loadmsg, $E003, .sizeof(loadmsg), mode_up
 	jsr loadfile
 	rts

 .segment "RODATA"

 savemsg: .byte "Saving file ...",10
 fswrite: .byte 10,5,0,"write"

 .segment "STARTUP"

 cmd_save:
 	lda inputlen
 	cmp #$06
 	bcs :+
 	rts
 :	dmacopy fsopenf, $D001, 8, mode_up ; Copy 10,4,0,"open",10
 	lda #$05 ; inputlen
 	sta good
 	jsr loadinput
 	lda #10
 	sta $D001
 	lda #1
 	sta $D001
 	stz $D001
 	lda #'w'
 	sta $D001
 	stz $D001 ; TSF End Tag
 	stz $D000 ; Invoke
 	lda $D000
 	cmp #$00
 	beq :+
 	dmacopy openfail, $E003, .sizeof(openfail), mode_up ; No file opened
 	rts
 :	dmacopy savemsg, $E003, .sizeof(savemsg), mode_up
 	dmacopy fswrite, $D001, .sizeof(fswrite), mode_up ; Copy write command
 	dmacopy $D001, $0008, 5, mode_pu ; Save handle
 	dmacopy $0008, $D001, 5, mode_up
 	lda #9
 	sta $D001
 	ldx curlow
 	stx $D001
 	ldy curhigh
 	dey
 	dey
 	sty $D001
 	stz $E041
 	lda #$02 ; Setup Copy Engine
 	sta $E042
 	lda #$01
 	sta $E043
 	lda #$D0
 	sta $E044
 	stx $E045
 	sty $E046
 	lda #mode_up ; Copy
 	sta $E040
 	stz $E046 ; Put high byte back to zero
 	stz $D001 ; TSF End Tag
 	stz $D000 ; Invoke
 	jsr closehandle
 	rts

 cmd_run:
 	jmp $0200

 .segment "RODATA"

 .byte "]]error",$22,"Thistle architecture required",$22,"--"

 .segment "STARTUP"

 nmi:
 	rti

 irq:
 	rti

 .segment	"VECTORS"

 .word nmi
 .word reset
 .word irq
	;
	; Thistle Boot ROM
	;
	.setcpu "65c02"

	.segment "STARTUP"

	.byte "--[[CABE:Thistle:"

	.segment "RODATA"

	; TSF Component Data
	fslist: .byte 10,10,0,"filesystem",0
	umlist: .byte 10,5,0,"drive",0
	secread: .byte 10,10,0,"readSector",3,1,0
	fsopend: .byte 10,4,0,"open",10,12,0,"Thistle/boot",0
	fsopenf: .byte 10,4,0,"open",10,7,0,"Thistle",0
	fsclose: .byte 10,5,0,"close"
	fsread: .byte 10,4,0,"read",14,0,0,0,0,4,0,1,0

	; Messages
	greeting: .byte "Thistle Boot ROM",10,10
	nomem: .byte "No Memory installed"
	drives: .byte "Checking drives ...",10
	fsmsg: .byte 10,"Checking filesystems ...",10
	bootmsg: .byte "Booting ...",10
	noboot: .byte "Nothing to boot from",10

	hexlookup: .byte "0123456789abcdef"

	unkcmd: .byte "Unknown Command",10

	cmdlist:
	.asciiz "ls"
	.word cmd_ls
	.asciiz "list"
	.word cmd_list
	.asciiz "load"
	.word cmd_load
	.asciiz "save"
	.word cmd_save
	.asciiz "run"
	.word cmd_run
	.asciiz ""

	.define inval $FF

	opcodetbl:
	.byte "BRK",$07,"ORA",$09,inval,$00,inval,$07,"TSB",$01,"ORA",$01,"ASL",$01,"RB0",$01,"PHP",$07,"ORA",$00,"ASL",$07,inval,$07,"TSB",$04,"ORA",$04,"ASL",$04,"BR0",$0E
	.byte "BPL",$08,"ORA",$0A,"ORA",$0D,inval,$07,"TRB",$01,"ORA",$02,"ASL",$02,"RB1",$01,"CLC",$07,"ORA",$06,"INC",$07,inval,$07,"TRB",$04,"ORA",$05,"ASL",$05,"BR1",$0E
	.byte "JSR",$04,"AND",$09,inval,$00,inval,$07,"BIT",$01,"AND",$01,"ROL",$01,"RB2",$01,"PLP",$07,"AND",$00,"ROL",$07,inval,$07,"BIT",$04,"AND",$04,"ROL",$04,"BR2",$0E
	.byte "BMI",$08,"AND",$0A,"AND",$0D,inval,$07,"BIT",$02,"AND",$02,"ROL",$02,"RB3",$01,"SEC",$07,"AND",$06,"DEC",$07,inval,$07,"BIT",$05,"AND",$05,"ROL",$05,"BR3",$0E
	.byte "RTI",$07,"EOR",$09,inval,$00,inval,$07,inval,$01,"EOR",$01,"LSR",$01,"RB4",$01,"PHA",$07,"EOR",$00,"LSR",$07,inval,$07,"JMP",$04,"EOR",$04,"LSR",$04,"BR4",$0E
	.byte "BVC",$08,"EOR",$0A,"EOR",$0D,inval,$07,inval,$02,"EOR",$02,"LSR",$02,"RB5",$01,"CLI",$07,"EOR",$06,"PHY",$07,inval,$07,inval,$04,"EOR",$05,"LSR",$05,"BR5",$0E
	.byte "RTS",$07,"ADC",$09,inval,$00,inval,$07,"STZ",$01,"ADC",$01,"ROR",$01,"RB6",$01,"PLA",$07,"ADC",$00,"ROR",$07,inval,$07,"JMP",$0B,"ADC",$04,"ROR",$04,"BR6",$0E
	.byte "BVS",$08,"ADC",$0A,"ADC",$0D,inval,$07,"STZ",$02,"ADC",$02,"ROR",$02,"RB7",$01,"SEI",$07,"ADC",$06,"PLY",$07,inval,$07,"JMP",$0C,"ADC",$05,"ROR",$05,"BR7",$0E
	.byte "BRA",$08,"STA",$09,inval,$00,inval,$07,"STY",$01,"STA",$01,"STX",$01,"SB0",$01,"DEY",$07,"BIT",$00,"TXA",$07,inval,$07,"STY",$04,"STA",$04,"STX",$04,"BS0",$0E
	.byte "BCC",$08,"STA",$0A,"STA",$0D,inval,$07,"STY",$02,"STA",$02,"STX",$03,"SB1",$01,"TYA",$07,"STA",$06,"TXS",$07,inval,$07,"STZ",$04,"STA",$05,"STZ",$05,"BS1",$0E
	.byte "LDY",$00,"LDA",$09,"LDX",$00,inval,$07,"LDY",$01,"LDA",$01,"LDX",$01,"SB2",$01,"TAY",$07,"LDA",$00,"TAX",$07,inval,$07,"LDY",$04,"LDA",$04,"LDX",$04,"BS2",$0E
	.byte "BCS",$08,"LDA",$0A,"LDA",$0D,inval,$07,"LDY",$02,"LDA",$02,"LDX",$03,"SB3",$01,"CLV",$07,"LDA",$06,"TSX",$07,inval,$07,"LDY",$05,"LDA",$05,"LDX",$06,"BS3",$0E
	.byte "CPY",$00,"CMP",$09,inval,$00,inval,$07,"CPY",$01,"CMP",$01,"DEC",$01,"SB4",$01,"INY",$07,"CMP",$00,"DEX",$07,"WAI",$07,"CPY",$04,"CMP",$04,"DEC",$04,"BS4",$0E
	.byte "BNE",$08,"CMP",$0A,"CMP",$0D,inval,$07,inval,$02,"CMP",$02,"DEC",$02,"SB5",$01,"CLD",$07,"CMP",$06,"PHX",$07,"STP",$07,inval,$04,"CMP",$05,"DEC",$05,"BS5",$0E
	.byte "CPX",$00,"SBC",$09,inval,$00,inval,$07,"CPX",$01,"SBC",$01,"INC",$01,"SB6",$01,"INX",$07,"SBC",$00,"NOP",$07,inval,$07,"CPX",$04,"SBC",$04,"INC",$04,"BS6",$0E
	.byte "BEQ",$08,"SBC",$0A,"SBC",$0D,inval,$07,inval,$02,"SBC",$02,"INC",$02,"SB7",$01,"SED",$07,"SBC",$06,"PLX",$07,inval,$07,inval,$04,"SBC",$05,"INC",$05,"BS7",$0E

	length: .byte 2,2,2,2,3,3,3,1,2,2,2,3,3,2,3

	format:
	.byte "#$__",$00,$00
	.byte "#'_'",$00,$00
	.byte "$__",$00,$01
	.byte "$__,X",$00,$02
	.byte "$__,Y",$00,$03
	.byte "$____",$00,$04
	.byte "$____,X",$00,$05
	.byte "$____,Y",$00,$06
	.byte "0X__",$00,$08
	.byte "-0X__",$00,$08
	.byte "($__,X)",$00,$09
	.byte "($__),Y",$00,$0a
	.byte "($____)",$00,$0b
	.byte "($____,X)",$00,$0c
	.byte "($__)",$00,$0d
	.byte "$__,0X__",$00,$0e
	.byte "$__,-0X__",$00,$0e
	.byte $00,$07 ; Must be last

	.segment "STARTUP"

	.define inputlen $80
	.define good $81
	.define formattype $82
	.define addrmode $83
	.define opcode $84
	.define indlow $85
	.define indhigh $86
	.define curlow $87
	.define curhigh $88

	.macro dmacopy src, dest, len, mode
	.ifnblank src
	.if .const(src) .and .lobyte(src) = 0
	stz $E041
	.else
	lda #<src
	sta $E041
	.endif
	.if .const(src) .and .hibyte(src) = 0
	stz $E042
	.else
	lda #>src
	sta $E042
	.endif
	.endif
	.ifnblank dest
	.if .const(dest) .and .lobyte(dest) = 0
	stz $E043
	.else
	lda #<dest
	sta $E043
	.endif
	.if .const(dest) .and .hibyte(dest) = 0
	stz $E044
	.else
	lda #>dest
	sta $E044
	.endif
	.endif
	.ifnblank len
	.if .const(len) .and len = 0
	stz $E045
	.else
	lda #<len
	sta $E045
	.endif
	.endif
	.if .const(mode) .and mode = 0
	stz $E040
	.else
	lda #mode
	sta $E040
	.endif
	.endmacro

	.macro dmaload src, dest, len
	.ifnblank src
	.if .const(src) .and .lobyte(src) = 0
	stz $E041
	.else
	lda #<src
	sta $E041
	.endif
	.if .const(src) .and .hibyte(src) = 0
	stz $E042
	.else
	lda #>src
	sta $E042
	.endif
	.endif
	.ifnblank dest
	.if .const(dest) .and .lobyte(dest) = 0
	stz $E043
	.else
	lda #<dest
	sta $E043
	.endif
	.if .const(dest) .and .hibyte(dest) = 0
	stz $E044
	.else
	lda #>dest
	sta $E044
	.endif
	.endif
	.ifnblank len
	.if .const(len) .and len = 0
	stz $E045
	.else
	lda #<len
	sta $E045
	.endif
	.endif
	.endmacro

	.define mode_pp $00
	.define mode_pu $01
	.define mode_up $02
	.define mode_uu $03

	hexprint:
	; Prints a byte to the screen
	; A - byte to print
	; Clobbers: X
	pha
	phy
	tax
	lsr
	lsr
	lsr
	lsr
	tay
	lda hexlookup,Y
	sta $E003
	txa
	and #$0F
	tay
	lda hexlookup,Y
	sta $E003
	ply
	pla
	rts

	uuidprint:
	; Prints a UUID to the screen
	; $00, $01 - Address of UUID
	; Clobbers: A, X (hexprint), Y
	ldy #$00
	@loop:
	lda (indlow),Y
	jsr hexprint
	iny
	cpy #$10
	beq @done
	cpy #$04
	beq @dash
	cpy #$06
	beq @dash
	cpy #$08
	beq @dash
	cpy #$0A
	beq @dash
	bra @loop
	@dash:
	lda #$2D
	sta $E003
	bra @loop
	@done:
	lda #$0a
	sta $E003
	rts

	_readlist:
	; Reads component list to $0200
	; $02 - Bytes to skip for component type
	; Clobbers: A, X, Y, indlow, indhigh
	lda $E011
	sta $03
	stz indlow
	ldy #$00
	lda #$02
	sta indhigh
	@loop1:
	lda $E012
	cmp #$00 ; TSF End Tag
	beq @done

	; Read UUID
	ldx #$10
	@loop2:
	lda $E012
	sta (indlow),Y
	jsr inc_y
	dex
	cpx #$00
	bne @loop2

	; Drop component name
	ldx $02
	@loop3:
	lda $E012
	dex
	cpx #$00
	bne @loop3
	bra @loop1
	@done:
	lda #$02
	sta indhigh
	rts

	.macro readlist skip
	lda #skip
	sta $02
	jsr _readlist
	.endmacro

	loaduuid:
	; Load a UUID into the component selector buffer
	; indlow, indhigh - Address to read from
	; Clobbers: A, X, Y, (uuidprint)
	jsr uuidprint
	loaduuid2:
	ldy indlow
	stz indlow
	ldx #$10
	lda #$0b ; UUID Tag
	sta $E012
	@loop:
	lda (indlow),Y ; UUID Byte loop
	sta $E012
	jsr inc_y
	dex
	cpx #$00
	bne @loop
	sty indlow
	stz $E012 ; End Tag
	stz $E010 ; Map Component
	rts

	closehandle:
	; Closes an open file handle
	; $08-$0C - Handle to close
	; Clobbers: A
	dmacopy fsclose, $D001, .sizeof(fsclose), mode_up ; Call close
	dmacopy $0008, , 5, mode_up ; ($0008, $D001, 5, mode_up)
	stz $D001
	stz $D000
	dmacopy , $E012, , mode_up ; ($0008, $E012, 5, mode_up) Destroy value
	stz $E012
	lda #$04
	sta $E010
	rts

	loadfile:
	; Reads a file into memory starting at $0200
	stz curlow
	lda #$02
	sta curhigh
	dmacopy fsread, $0001, .sizeof(fsread), mode_uu ; Copy read command
	dmacopy $D001, $0008, 5, mode_pu ; Inject handle
	@loop:
	ldx curhigh
	cpx #$D0
	beq @done ; Too much data read
	dmacopy $0001, $D001, .sizeof(fsread), mode_up ; Call "read"
	stz $D000

	lda $D001 ; Check TSF Tag
	cmp #$09 ; Byte array?
	beq :+
	cmp #$0A ; String?
	bne @done ; No more data to read

	: lda $D001 ; Read length
	sta indlow
	lda $D001
	sta indhigh
	ldy #$01 ; Setup Copy Engine
	sty $E041
	lda #$D0
	sta $E042
	clc ; Load address and add at same time
	lda curlow
	sta $E043
	adc indlow
	sta curlow
	lda curhigh
	sta $E044
	adc indhigh
	sta curhigh
	lda indlow
	sta $E045
	lda indhigh
	sta $E046
	sty $E040 ; Execute Copy Engine Command
	bra @loop
	@done:
	stz $E046 ; Put high byte of size back to 0
	jsr closehandle
	rts

	dispboot:
	dmacopy bootmsg, $E003, .sizeof(bootmsg), mode_up
	rts

	bootdrive:
	; Checks and boots from a drive
	lda $D000
	cmp #$00
	beq :+
	rts
	: jsr dispboot
	pla ; Remove address from stack
	pla ; We're not returning to havemem
	lda #$01 ; Setup Copy Engine
	sta $E041
	lda #$D0
	sta $E042
	stz $E043
	lda #$02
	sta $E044

	lda $D001 ; Discard tag
	lda $D001
	sta $E045
	lda $D001
	sta $E046

	lda #mode_pu ; Copy
	sta $E040

	stz $E046
	jsr $0200 ; Boot
	jmp fschk

	bootfs:
	; Boots from a file
	lda $D000
	cmp #$00
	beq :+
	rts ; No file opened
	: jsr dispboot
	pla ; Remove address from stack
	pla ; We're not returning to fschk
	jsr loadfile
	jsr $0200 ; Boot
	jmp commands

	reset:
	; Display boot greeting
	dmacopy greeting, $E003, .sizeof(greeting), mode_up

	; Memory Check
	lda $E018
	cmp #$00
	bne havemem
	lda $E019
	cmp #$00
	bne havemem
	; No Memory Installed
	dmacopy nomem, , .sizeof(nomem), mode_up ; (nomem, $E003, .sizeof(nomem), mode_up)
	@loop: bra @loop

	havemem:
	dmacopy drives, , .sizeof(drives), mode_up ; (drives, $E003, .sizeof(drives), mode_up)
	; Look for "drive" components
	dmacopy umlist, $E012, .sizeof(umlist), mode_up
	lda #$03
	sta $E010
	readlist 8 ; Store list to memory

	; Parse list
	@loop:
	lda $03
	cmp #$00
	beq fschk ; No "drive" componets left to check
	jsr loaduuid
	dmacopy secread, $D001, .sizeof(secread), mode_up ; Call readSector
	stz $D000
	jsr bootdrive
	dec $03
	bra @loop

	fschk:
	dmacopy fsmsg, $E003, .sizeof(fsmsg), mode_up
	; Look for "filesystem" components
	dmacopy fslist, $E012, .sizeof(fslist), mode_up
	lda #$03
	sta $E010
	readlist 13 ; Store list to memory

	; Parse list
	@loop:
	lda $03
	cmp #$00
	bne :+
	jmp failboot ; No "filesystem" componets left to check
	: jsr loaduuid
	dmaload , $D001
	dmacopy fsopend, , .sizeof(fsopend), mode_up ; (fsopend, $D001, .sizeof(fsopend), mode_up) open Thistle/boot
	stz $D000
	jsr bootfs
	dmacopy fsopenf, , .sizeof(fsopenf), mode_up ; (fsopenf, $D001, .sizeof(fsopenf), mode_up) open Thistle
	stz $D000
	jsr bootfs
	dec $03
	bra @loop

	hex2val:
	; Converts two hexadecimal characters to a value
	lda $00,X
	clc
	sbc #$2f
	cmp #$11
	bcc :+
	clc
	sbc #$06
	: sta good
	dex
	lda $00,X
	clc
	sbc #$2f
	cmp #$11
	bcc :+
	clc
	sbc #$06
	: asl
	asl
	asl
	asl
	eor good
	dex
	sta (curlow),Y
	iny
	rts

	inc_y:
	; Handle page wraps
	iny
	cpy #$00
	bne :+
	inc indhigh
	: rts

	failboot:
	dmacopy noboot, $E003, .sizeof(noboot), mode_up

	; Try to select a non tmpfs filesystem
	dmacopy fslist, $E012, .sizeof(fslist), mode_up
	lda #$03
	sta $E010
	readlist 13 ; Store list to memory

	@loop:
	lda $03
	cmp #$00
	beq commands
	ldx #$00
	ldy #$00
	stz good
	@loop2:
	lda (indlow),Y
	cmp $E110,X
	beq :+
	sty good
	lda indlow
	clc
	adc good
	stx good
	sec
	sbc indlow
	sta indlow
	jsr loaduuid2
	bra commands
	: inx
	jsr inc_y
	cpx #$10
	bne @loop2
	ldx #$00
	dec $03
	bra @loop

	commands:
	stz $E001 ; Drop all input
	stz curlow
	lda #$02
	sta curhigh
	@setup: lda #'$'
	sta $E003
	lda curhigh
	jsr hexprint
	lda curlow
	jsr hexprint
	ldx #' '
	stx $E003
	lda #'>'
	sta $E003
	stx $E003
	stz inputlen
	@loop: lda $E000
	cmp #$00
	beq @loop ; No Input
	ldx inputlen
	lda $E001
	cmp #$00 ; Scancode, discard
	bne :+
	lda $E001
	bra @loop
	: cmp #$08 ; Backspace
	bne :+
	cpx #$00
	beq @loop ; No input to delete
	sta $E003
	dec inputlen
	bra @loop
	: cmp #$0A ; Enter
	beq @exec
	cpx #$80 ; Character
	beq @loop
	sta $E003
	sta $00,X
	inc inputlen
	bra @loop
	@exec:
	sta $E003
	cpx #$00 ; No Input
	beq @setup
	; @setup for comparing cmd names
	lda #<cmdlist
	sta indlow
	lda #>cmdlist
	sta indhigh
	ldx #$00
	ldy #$00
	stz good
	; Compare against cmd list
	@ncloop:
	lda (indlow),Y
	cmp #$00 ; NUL, end of cmd name
	beq @nccheck
	cmp $00,X ; Matches
	beq :+
	smb0 good ; Mark as bad
	: inx
	jsr inc_y
	bra @ncloop
	@nccheck:
	jsr inc_y
	cpx #$00 ; No more cmd entries?
	beq @asm
	cmp good ; A = $00
	bne @ncbad
	cpx inputlen
	beq @ncfound
	lda $00,X
	cmp #' '
	beq @ncfound
	@ncbad:
	stz good ; Did not match, reset
	ldx #$00
	jsr inc_y ; Skip over address
	jsr inc_y
	bra @ncloop
	@ncfound:
	lda #$4C ; JMP $XXXX
	sta opcode
	lda (indlow),Y
	tax
	jsr inc_y
	lda (indlow),Y
	stx indlow
	sta indhigh
	jsr opcode
	jmp @setup
	@asm:
	; Assembly code!
	; Uppercase it all
	ldx #$00
	@ucloop:
	lda $00,X
	clc
	sbc #$60
	bmi :+
	adc #$40
	sta $00,X
	: inx
	cpx inputlen
	bne @ucloop
	; Setup for comparing format strings
	ldx #$04
	ldy #$00
	stz formattype
	stz good
	lda inputlen
	cmp #$03 ; Three characters?
	bcs :+
	jmp @badcmd
	: beq @amloop
	lda $03
	cmp #$20
	beq @amloop
	jmp @badcmd ; 4th character not a space
	; Identify addressing mode
	@amloop:
	lda format,Y
	cmp #$00 ; NUL, end of format string
	beq @amcheck
	cmp #$5F ; Underscore
	beq :+
	cmp $00,X ; Matches
	beq :+
	smb0 good ; Mark as bad
	: inx
	iny
	bra @amloop
	@amcheck:
	iny
	cpx #$04 ; No more format entries?
	beq @amfound ; Assume implied
	cmp good ; A = $00
	bne @ambad
	cpx inputlen
	beq @amfound
	bcs @ambad ; Not enough imput
	lda $00,X
	cmp #' '
	beq @amfound
	@ambad:
	stz good ; Wrong addressing mode, reset
	ldx #$04
	iny
	inc formattype
	bra @amloop
	@amfound:
	lda format,Y
	sta addrmode
	lda #<opcodetbl
	sta indlow
	lda #>opcodetbl
	sta indhigh
	ldy #$00
	ldx #$00
	stz opcode
	stz good
	; Compare opcode names
	@oploop:
	lda (indlow),Y
	cmp $00,X
	beq :+
	smb0 good ; Mark as bad
	: inx
	jsr inc_y
	cpx #$03
	beq @opcheck
	cmp #$FF
	beq @opcheck
	bra @oploop
	@opcheck:
	lda (indlow),Y
	cmp addrmode
	beq :+
	smb0 good ; Mark as bad
	: lda #$00
	cmp good
	beq @opfound

	stz good ; Wrong opcode, reset
	ldx #$00
	jsr inc_y
	inc opcode
	lda opcode
	cmp #$00 ; Wrapped back to 0
	bne :+
	jmp @badcmd
	: bra @oploop
	@opfound:
	ldy #$00
	lda opcode
	sta (curlow),Y ; Write opcode to memory
	iny
	lda formattype
	cmp #$00 ; immediate
	beq @read21
	cmp #$01 ; immediate w/ character
	beq @readchar
	cmp #$02 ; zeropage
	beq @read20
	cmp #$03 ; zp indexed x
	beq @read20
	cmp #$04 ; zp indexed y
	beq @read20
	cmp #$05 ; absolute
	beq @read40
	cmp #$06 ; indexed x
	beq @read40
	cmp #$07 ; indexed y
	beq @read40
	cmp #$08 ; relative
	beq @read21
	cmp #$09 ; relative w/ minus
	beq @relminus
	cmp #$0a ; zp indirect x
	beq @read21
	cmp #$0b ; zp indirect y
	beq @read21
	cmp #$0c ; indirect
	beq @read41
	cmp #$0d ; indirect x
	beq @read41
	cmp #$0e ; zp indirect
	beq @read21
	cmp #$0f ; zp relative
	beq @readzpr
	cmp #$10 ; zp relative minus
	beq @zprminus
	bra @opskip
	@readchar:
	ldx #$06
	lda $00,X
	sta (curlow),Y
	bra @opskip
	@read20:
	ldx #$06
	jsr hex2val
	bra @opskip
	@read21:
	ldx #$07
	jsr hex2val
	bra @opskip
	@read40:
	ldx #$08
	jsr hex2val
	jsr hex2val
	bra @opskip
	@read41:
	ldx #$09
	jsr hex2val
	jsr hex2val
	bra @opskip
	@readzpr:
	ldx #$06
	jsr hex2val
	ldx #$0b
	jsr hex2val
	bra @opskip
	@zprminus:
	ldx #$06
	jsr hex2val
	ldx #$0c
	bra :+
	@relminus:
	ldx #$08
	: jsr hex2val
	dey
	sec
	lda #$00
	sbc (curlow),Y
	sta (curlow),Y
	@opskip:
	ldy addrmode
	ldx length,Y
	ldy curlow
	@incloop:
	iny
	cpy #$00
	bne :+
	inc curhigh
	: dex
	cpx #$00
	bne @incloop
	sty curlow
	bra :+
	@badcmd:
	dmacopy unkcmd, $E003, .sizeof(unkcmd), mode_up ; (unkcmd, $E003, .sizeof(unkcmd), mode_up)
	: jmp @setup

	loadinput:
	; Loads string from input buffer into Component 1
	lda inputlen
	cmp good
	bcs :+
	lda good
	: clc
	sbc good
	inc
	sta $D001
	sta $E045 ; Copy Engine Length
	stz $D001

	lda good ; Setup Copy Engine
	sta $E041
	stz $E042
	lda #$01
	sta $E043
	lda #$D0
	sta $E044
	lda #mode_up ; Copy
	sta $E040
	rts

	.segment "RODATA"

	listtest: .byte 10,4,0,"list",10
	listfail: .byte "Listing failed",10

	.segment "STARTUP"

	cmd_ls:
	lda #$03 ; inputlen
	sta good
	bra :+
	cmd_list:
	lda #$05 ; inputlen
	sta good
	: dmacopy listtest, $D001, .sizeof(listtest), mode_up
	jsr loadinput
	stz $D001 ; TSF End Tag
	stz $D000 ; Invoke
	lda $D000
	cmp #$00
	beq :+
	dmacopy listfail, $E003, .sizeof(listfail), mode_up
	rts
	: lda $D001 ; Drop Array Tag
	@loop:
	lda $D001
	cmp #$00 ; TSF End Tag
	beq @done
	ldy $D001 ; Length low
	ldx $D001 ; Length high
	@readloop:
	cpy #$00
	bne :+
	cpx #$00
	bne :+
	lda #$0A
	sta $E003
	bra @loop
	: lda $D001
	sta $E003
	dey
	cpy #$FF
	bne :+
	dex
	: bra @readloop
	@done:
	rts

	.segment "RODATA"

	openfail: .byte "Could not open file",10
	loadmsg: .byte "Loading file ...",10

	.segment "STARTUP"

	cmd_load:
	lda inputlen
	cmp #$06
	bcs :+
	rts
	: dmacopy fsopenf, $D001, 8, mode_up ; Copy 10,4,0,"open",10
	lda #$05 ; inputlen
	sta good
	jsr loadinput
	stz $D001 ; TSF End Tag
	stz $D000 ; Invoke
	lda $D000
	cmp #$00
	beq :+
	dmacopy openfail, $E003, .sizeof(openfail), mode_up ; No file opened
	rts
	: dmacopy loadmsg, $E003, .sizeof(loadmsg), mode_up
	jsr loadfile
	rts

	.segment "RODATA"

	savemsg: .byte "Saving file ...",10
	fswrite: .byte 10,5,0,"write"

	.segment "STARTUP"

	cmd_save:
	lda inputlen
	cmp #$06
	bcs :+
	rts
	: dmacopy fsopenf, $D001, 8, mode_up ; Copy 10,4,0,"open",10
	lda #$05 ; inputlen
	sta good
	jsr loadinput
	lda #10
	sta $D001
	lda #1
	sta $D001
	stz $D001
	lda #'w'
	sta $D001
	stz $D001 ; TSF End Tag
	stz $D000 ; Invoke
	lda $D000
	cmp #$00
	beq :+
	dmacopy openfail, $E003, .sizeof(openfail), mode_up ; No file opened
	rts
	: dmacopy savemsg, $E003, .sizeof(savemsg), mode_up
	dmacopy fswrite, $D001, .sizeof(fswrite), mode_up ; Copy write command
	dmacopy $D001, $0008, 5, mode_pu ; Save handle
	dmacopy $0008, $D001, 5, mode_up
	lda #9
	sta $D001
	ldx curlow
	stx $D001
	ldy curhigh
	dey
	dey
	sty $D001
	stz $E041
	lda #$02 ; Setup Copy Engine
	sta $E042
	lda #$01
	sta $E043
	lda #$D0
	sta $E044
	stx $E045
	sty $E046
	lda #mode_up ; Copy
	sta $E040
	stz $E046 ; Put high byte back to zero
	stz $D001 ; TSF End Tag
	stz $D000 ; Invoke
	jsr closehandle
	rts

	cmd_run:
	jmp $0200

	.segment "RODATA"

	.byte "]]error",$22,"Thistle architecture required",$22,"--"

	.segment "STARTUP"

	nmi:
	rti

	irq:
	rti

	.segment "VECTORS"

	.word nmi
	.word reset
	.word irq