Delete lessons directory

README.md

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 # 6502code
-Code I've collected while creating my Udemy 6502 Assembly Programming course.
+Code I've collected while creating videos.
 Also, two fonts I created that replicate the Apple II screen font and their official manual font.

lessons/lesson1a.txt

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-08FC-00 09             6         .DA     PROG_BEGIN
-08FE-50 00             7         .DA PROG_END-PROG_BEGIN
-FDF0-                  8 cout    .eq $fdf0
-0900-                  9
-0900-                 10 PROG_BEGIN
-0900-                 11 * part 1
-0900-A9 C1            12         lda #"A"	; spelling out "APPLE"
-0902-20 F0 FD         13         jsr cout	; and outputting using
-0905-A9 F0            14         lda #"p"	; the built-in monitor
-0907-20 F0 FD         15         jsr cout	; routines
-090A-20 F0 FD         16         jsr cout	; directly printing
-090D-A9 EC            17         lda #"l"	; one letter at a time
-090F-20 F0 FD         18         jsr cout
-0912-A9 E5            19         lda #"e"
-0914-20 F0 FD         20         jsr cout
-0917-60               21         rts
-0918-                 22
-0918-                 23 * part 2
-0918-A2 05            24         ldx #$05	; the number of letters
-091A-BD 23 09         25 more2   lda text-1,x	; place in acc like before
-091D-20 F0 FD         26         jsr cout	; print it
-0920-CA               27         dex		; decrease x-index register by one (1)
-0921-D0 F7            28         bne more2	; still have more to print
-0923-60               29 done    rts
-0924-E5 EC F0 F0 
-     C1               30 text    .hs e5ecf0f0c1	; elppA (backwards Apple)
-0929-                 31
-0929-                 32 * part 3
-0929-A2 00            33         ldx #$00	; load our index with zero
-092B-BD 36 09         34 more3   lda text2,x	; grab the text form below
-092E-F0 F3            35         beq done	; if it's 00, no more text
-0930-20 F0 FD         36         jsr cout	; print it
-0933-E8               37         inx		; get next letter
-0934-D0 F5            38         bne more3	; branch if x is not equal to zero (0)
-0936-C1 F0 F0 EC 
-     E5 00            39 text2   .hs c1f0f0ece500	; text in order (Apple)
-093C-                 40			; with trailing zero (0)
-093C-                 41 * part 4
-0000-                 42 zploc   .eq     $00	; define our zero-page address
-093C-A9 36            43         lda #text2	; put the pointer in zero-page
-093E-85 00            44         sta zploc	; lower byte --> zero page
-0940-A9 09            45         lda /text2	; grab higher byte of address
-0942-85 01            46         sta zploc+1	; higher byte --> zero page
-0944-A0 00            47         ldy #$00	; set index to zero (0)
-0946-B1 00            48 more4   lda (zploc),y	; grab indirect index to our text
-0948-F0 D9            49         beq done	; if zero (0) then exit
-094A-20 F0 FD         50         jsr cout	; print it!
-094D-C8               51         iny		; increment our index to get the next letter
-094E-D0 F6            52         bne more4	; branch of y is not zero (0)
-0950-                 53
-0950-                 54 PROG_END
-

source/block_000.txt

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+ xc
+ org $800
+
+* Equates
+cold equ $1200
+key equ $c000
+strobe equ $c010
+home equ $fc58
+cout equ $fded
+mainread equ $C002
+auxread equ $C003
+mainwrite equ $C004
+auxwrite equ $C005
+
+* Code
+ hex 01
+ txa  ; #$50 = %0101 0000
+ pha
+ lsr  ; > 0010 1000
+ lsr  ; > 0001 0100
+ lsr  ; > 0000 1010
+ lsr  ; > 0000 0101
+ ora #$C0 ; > #$C5
+ pha
+ sta reboot+2 ; in case we need to reboot
+ sta a1+2 ; fix entry address for ProDOS PC entry
+ sta a3+2 ; fix call address for PC entry
+a1 lda $FFFF ; > $C5FF
+ clc
+ adc #3 ; get PC entry low byte
+ sta a3+1 ; set PC entry byte
+
+* Check for 128K
+ jsr chk80
+ bcs error
+
+* Check for 65C02 processor
+ lda #$99
+ clc
+ sed
+ adc #1
+ cld
+ bpl a2 ; success!
+
+* Error routine
+error lda #<msg1 ;4C 00 20
+ sta pr1+1
+ lda #>msg1
+ sta pr1+2
+ jsr print
+ sta strobe
+restart lda key
+ bpl restart
+ sta strobe
+reboot jmp $FF00
+
+* Load blocks 000000-000018
+a2 lda #<msg2
+ sta pr1+1
+ lda #>msg2
+ sta pr1+2
+ jsr print
+
+a3 jsr $FFFF ; call PC
+ hex 01 ; read block
+ da rdblock
+ bcs error
+ inc rbuffer+1
+ inc rbuffer+1
+ inc rblock
+
+* read equivalent of three tracks (24 blocks)
+ lda rblock
+ cmp #25 ; $19
+ bcc a3 ; blocks 0-24 > $1000-3FFF
+ pla  ; $Cx
+ sta $fe
+ pla  ; $x0
+ sta $ff
+ ldx $ff
+ txs
+ jmp cold
+
+* print message routine
+print jsr home ; home/clear screen
+ ldy #0
+pr1 lda $ffff,y
+ beq pr2
+ jsr cout ; print ASCII char on screen
+ iny
+ bne pr1
+pr2 rts
+
+* check for 128K memory
+chk80 clc
+ ldx #rend-routine
+move lda routine,x
+ sta $100,x
+ dex
+ bpl move
+ jmp $0100
+
+* routine from ProDOS 8
+routine lda #$ee
+ sta auxread ; loads in aux $0200-BFFF
+ sta auxwrite
+ sta $0c00
+ sta $7c00
+ lda $0c00
+ cmp #$ee ; first check
+ bne noaux
+ asl $0c00
+ asl
+ cmp $0c00 ; second check
+ bne noaux
+ cmp $7c00 ; third check
+ bne auxil
+noaux sec
+ bcs r1
+auxil clc
+r1 sta mainread
+ sta mainwrite
+ rts
+rend equ *
+
+* Messages
+msg1 asc "ERROR LOADING.",8d
+ asc "PRESS ANY KEY TO RESTART:",00
+msg2 asc "FIFTH programming language v0.01a",8d
+ asc "Just a moment...",00
+
+* PC call block
+rdblock hex 03 ; parameter count
+ hex 01 ; unit number
+rbuffer hex 0010 ; $1000
+rblock hex 000000 ; block number to read
+
+
+
+
+ xc
+ org $1200
+cout equ $fded
+monz equ $ff69 ; call-151
+
+ ldy #msgend-msg
+loop lda msg,y
+ jsr cout
+ dey
+ bpl loop
+ jmp monz
+
+msg rev "Reached $1200, second stage boot"
+msgend equ *
+
+
+
+
+
+