Added GPLv2.

We're now Free Software!!!

3 files changed, 269 insertions, 51 deletions

diff --git a/programs/forg.s b/programs/forg.s
new file mode 100644
index 0000000..3e6aea1
--- /dev/null
+++ b/programs/forg.s
@@ -0,0 +1,17 @@
+forg:
+	iny		; Increment offset.
+	lda buf, y
+	jsr iswhite
+	bcs forg	; Reset y, if we hit the null terminator.
+	cmp #$2E	; Is this character a '.'?
+	bne forg_exit	; No, so return.
+	sty org		; Yes, so store the origin.
+forg_end:
+	iny		; Increment offset.
+	lda buf, y
+	jsr istoken
+	bcs forg_end
+	dey
+	sty scr_col
+forg_exit:
+	rts		; End of forg.
diff --git a/programs/hex-to-bcd.s b/programs/hex-to-bcd.s
new file mode 100644
index 0000000..53a3ff2
--- /dev/null
+++ b/programs/hex-to-bcd.s
@@ -0,0 +1,7 @@
+hex_to_bcd:
+	pla #1		; Get argument.
+	div #10		; Divide A by 10.
+	lsl #4		; Shift the result left by 4 bits.
+	oab		; Or the result, with the remainder.
+	pha #1		; Push the packed BCD result to the stack.
+	rts		; Return the result.
diff --git a/programs/subasm.s b/programs/subasm.s
index ddb7ba2..50f2e8d 100644
--- a/programs/subasm.s
+++ b/programs/subasm.s
@@ -12,6 +12,111 @@ ver_txt:
 ver_num:
 	.byte "0.1"
 
+; Directives.
+dir:
+	.byte "org"
+	.byte "byte"
+	.byte "word"
+	.byte "dword"
+	.byte "qword"
+
+; Instruction mnemonics.
+mne:
+	.byte "CPS"
+	.byte "ADC"
+	.byte "AAB"
+	.byte "PHB"
+	.byte "PHP"
+	.byte "PHA"
+	.byte "PHY"
+	.byte "TAY"
+	.byte "PHX"
+	.byte "TAX"
+	.byte "TYX"
+	.byte "JMP"
+	.byte "SBC"
+	.byte "SAB"
+	.byte "PLB"
+	.byte "PLP"
+	.byte "PLA"
+	.byte "PLY"
+	.byte "TYA"
+	.byte "PLX"
+	.byte "TXA"
+	.byte "TXY"
+	.byte "JSR"
+	.byte "AND"
+	.byte "ABA"
+	.byte "STT"
+	.byte "TAB"
+	.byte "TSX"
+	.byte "BPO"
+	.byte "ORA"
+	.byte "OAB"
+	.byte "TBA"
+	.byte "SEI"
+	.byte "TXS"
+	.byte "BNG"
+	.byte "XOR"
+	.byte "XAB"
+	.byte "CLI"
+	.byte "BCS"
+	.byte "LSL"
+	.byte "LLB"
+	.byte "STB"
+	.byte "SEC"
+	.byte "STA"
+	.byte "STY"
+	.byte "STX"
+	.byte "BCC"
+	.byte "LSR"
+	.byte "LRB"
+	.byte "LDB"
+	.byte "CLC"
+	.byte "LDA"
+	.byte "LDY"
+	.byte "LDX"
+	.byte "BEQ"
+	.byte "ROL"
+	.byte "RLB"
+	.byte "SSP"
+	.byte "BNE"
+	.byte "ROR"
+	.byte "RRB"
+	.byte "CSP"
+	.byte "BVS"
+	.byte "MUL"
+	.byte "MAB"
+	.byte "SEV"
+	.byte "BVC"
+	.byte "DIV"
+	.byte "DAB"
+	.byte "CLV"
+	.byte "RTS"
+	.byte "CMP"
+	.byte "CAB"
+	.byte "CPY"
+	.byte "CPX"
+	.byte "CPB"
+	.byte "ENT"
+	.byte "RTI"
+	.byte "INC"
+	.byte "IAB"
+	.byte "INY"
+	.byte "INX"
+	.byte "DEC"
+	.byte "DBA"
+	.byte "DEY"
+	.byte "DEX"
+	.byte "WAI"
+	.byte "JSL"
+	.byte "ASR"
+	.byte "ARB"
+	.byte "NOP"
+	.byte "RTL"
+	.byte "BRK"
+
+
 scr_row:
 	.byte $0
 scr_col:
@@ -31,6 +136,13 @@ str_buf:
 .org $2000
 buf:
 
+.org $2400
+ptr1:
+	.qword $2500
+
+ptr2:
+	.qword $2900
+
 ; Control Register.
 .org $C000
 ctrl_reg:
@@ -49,22 +161,22 @@ reset:
 	cps
 	ldx.w #$FFFF
 	txs
-	ldy #$0
+	ldy #0
 	jsr clr_buf
-	ldx.w #$0	; Reset x.
-	ldy #$0		; Reset y.
+	ldx.w #0	; Reset x.
+	ldy #0		; Reset y.
 	jmp print_title
 
 read:
 	lda ctrl_reg	; Is the keyboard ready?
 	beq read	; Loop until the keyboard is ready.
-	lda #$0		; Start resetting the control register.
+	lda #0		; Start resetting the control register.
 	sta ctrl_reg	; Reset the control register.
 	jmp getchar	; We got a key.
 
 rset_x:
 
-	ldx #$0		; Reset x.
+	ldx #0		; Reset x.
 	stx.w x
 	rts
 
@@ -94,7 +206,7 @@ getline:
 	lda #$A
 	sta scr		; Print newline
 	inc scr_row
-	lda #$0
+	lda #0
 	sta scr_col
 	inc y
 	jsr rset_x
@@ -106,7 +218,7 @@ getchar:
 	beq esc		; Yes, so start getting the escape code.
 	cmp #$A		; Did the user type a newline?
 	beq nl		; Yes, so start parsing the input.
-	cmp #$8		; Did the user type a backspace?
+	cmp #8		; Did the user type a backspace?
 	beq bs		; Yes, so start checking the buffer.
 	jsr echo	; Print character to screen.
 
@@ -123,16 +235,16 @@ esc:
 	sta c		; Store the escape code, until we need it.
 	jsr isup	; Check if the user pressed up.
 	lda d
-	cmp #$0
+	cmp #0
 	bne esc_end
 	jsr isdown	; Check if the user pressed down.
 	lda d
-	cmp #$0
+	cmp #0
 	bne esc_end
-	lda #$0
+	lda #0
 	jsr isleft	; Check if the user pressed left.
 	lda d
-	cmp #$0
+	cmp #0
 	bne esc_end
 	jsr isright	; Check if the user pressed right.
 esc_end:
@@ -181,13 +293,13 @@ isleft_done:
 up:
 	dec scr_row
 	jsr update_pos
-	lda #$1
+	lda #1
 	sta d
 	jmp isup_done
 down:
 	inc scr_row
 	jsr update_pos
-	lda #$1
+	lda #1
 	sta d
 	jmp isdown_done
 right:
@@ -197,7 +309,7 @@ right:
 left:
 	dec scr_col
 	jsr update_pos
-	lda #$1
+	lda #1
 	sta d
 	jmp isleft_done
 
@@ -237,47 +349,81 @@ getcol:
 nl:
 	sta scr		; Print newline.
 	inc scr_row	; Move the cursor down one line.
-	lda #$0		; Put a null terminator, in place of the newline.
+	lda #0		; Put a null terminator, in place of the newline.
 	sta scr_col	; Move the cursor back to column 0.
-	sta str_buf, y	; Place it into the input buffer.
-	ldy.w #$0	; Reset y, to parse the input.
+	sta buf, y	; Place it into the input buffer.
+	ldy.w #0	; Reset y, to parse the input.
 	jsr parse	; Start parsing input.
 
 back:
 	sta scr		; Print backspace.
-	lda #$0		; Put a null terminator, in place of the backspace.
-	sta str_buf, y	; Place it into the input buffer.
+	lda #0		; Put a null terminator, in place of the backspace.
+	sta buf, y	; Place it into the input buffer.
 	dey		; Decrement buffer offset.
 	dec scr_col
 	jmp read	; Get next character.
 
 bs:
-	cpy #$0		; Are we at the start of the buffer?
+	cpy #0		; Are we at the start of the buffer?
 	beq read	; We are, so do not store the backspace into the buffer.
 	jmp back	; We are not, so add the backspace to the buffer.
 
 parse:
-	jmp parse	; Keep printing.
-	jsr clr_sbuf
+	jsr getdir
+	jsr
 	rts
 
-forg:
+getdir:
 	iny		; Increment offset.
-	lda str_buf, y
+	lda buf, y
 	jsr iswhite
-	bcs forg	; Reset y, if we hit the null terminator.
+	bcs getdir	; Reset y, if we hit the null terminator.
 	cmp #$2E	; Is this character a '.'?
-	bne forg_exit	; No, so return.
-	sty org		; Yes, so store the origin.
-forg_end:
+	bne getdir_exit	; No, so return.
+	jsr clr_ptr
+
+getdir_end:
 	iny		; Increment offset.
-	lda str_buf, y
+	lda buf, y
+	jsr iswhite
+	bcs getdir_cmp
+	ora #%00100000	; Make character lower case.
+	sta (ptr1), y
+	jmp getdir_end
+gettok:
+	ply #1
+	iny
+gettok2:
+	lda buf, y
 	jsr istoken
-	bcs forg_end
-	dey
-	sty scr_col
-forg_exit:
-	rts		; End of forg.
+	bcs gettok3
+	jmp gettok2
+gettok3:
+	cmp #$
+	cmp #$24	; Is this character, a '$'?
+	beq getaddr	; Yes, so start getting the address.
+
+
+
+getdir_cmp:
+	phy #1
+	ldy.w #0
+	tyx
+getdir_cpl:
+	ldb dir, x	; Start checking if the directive we're using, is "org".
+	stb (ptr2), y
+	beq getdir_scmp
+	inx
+	iny
+	jmp getdir_cpl
+getdir_scmp:
+	ldy #0
+	jsr strcmp
+	cpx #0
+	beq getdir_tok
+getdir_exit:
+	rts		; End of getdir.
+
 
 istoken:
 	cmp #$20	; Is this character a space?
@@ -288,7 +434,7 @@ istoken:
 	beq istoken_f	; Yes, so return false.
 	cmp #$3B	; Is this character a ';'?
 	beq istoken_f	; Yes, so return false.
-	cmp #$0		; Is this character a null terminator?
+	cmp #0		; Is this character a null terminator?
 	beq istoken_f	; Yes, so return false.
 	sec		; Return true.
 	rts		; End of istoken.
@@ -299,7 +445,7 @@ istoken_f
 iswhite:
 	cmp #$20	; Is this character a space?
 	beq iswhite_t	; Yes, so return true.
-	cmp #$09	; Is this character a tab?
+	cmp #9		; Is this character a tab?
 	beq iswhite_t	; Yes, so return true.
 	clc		; No, so return false.
 	rts		; End of iswhite.
@@ -308,7 +454,7 @@ iswhite_t:
 	rts		; End of iswhite_t.
 
 rset_y:
-	ldy.w #$0
+	ldy.w #0
 	jmp print_buf	; Print the input buffer.
 
 print_buf:
@@ -325,15 +471,15 @@ spin:
 	jmp spin
 
 clr_buf:
-	lda #$0
-	cpy.w #$1000
+	lda #0
+	cpy.w #$3FF
 	beq clr_end
 	sta buf, y
 	iny
 	jmp clr_buf
 clr_sbuf:
-	lda #$0
-	cpy.w #$40
+	lda #0
+	cpy.w #$1FF
 	beq clr_end
 	sta str_buf, y
 	iny
@@ -343,7 +489,7 @@ clr_end:
 	rts
 
 echo:
-	sta a
+	tab
 	ldx scr_col
 	cpx #$4F
 	bne echo_print
@@ -351,17 +497,51 @@ echo:
 	beq linewrap
 linewrap:
 	inc scr_row
-	ldx #$0
+	ldx #0
 	stx scr_col
 	jsr update_pos
 echo_print:
-	lda a
+	tba
 	sta scr		; Echo typed character.
 	inc scr_col	; Increment the cursor's x coordinate.
-	sta str_buf, y	; Store typed character into the input buffer.
+	sta buf, y	; Store typed character into the input buffer.
 	iny		; Increment the buffer offset.
 	rts		; Return.
 
+clr_ptr:
+	lda #0
+	cpy.w #$3FF
+	beq ptr_end
+	sta (ptr1), y
+	sta (ptr2), y
+	iny
+	jmp clr_ptr
+ptr_end:
+	rts
+
+strcmp:
+	lda (ptr1), y
+	cmp (ptr2), y
+	bne strcmp_l1
+	tax
+	beq strcmp_l3
+	iny
+	bne strcmp
+	jmp strcmp
+
+
+strcmp_l1:
+	bcs strcmp_l2
+	ldx #0
+	dex
+	rts
+
+strcmp_l2:
+	ldx #1
+strcmp_l3:
+	rts
+
+
 .org $FFC0
 .qword reset
 
@@ -376,9 +556,23 @@ echo_print:
 
 .org $FFA0
 .qword irq_routine
-;.org $0
-;viewmem
-;.org $100
-;viewmem
-;q
-done
+.org $0
+v
+.org $100
+v
+.org $200
+v
+.org $300
+v
+.org $1000
+v
+.org $1100
+v
+.org $1200
+v
+.org $1300
+v
+.org $1400
+v
+q
+