MDBASIC is an extension to the Commodore 64 BASIC V2.

Download the documentation file mdbasic.pdf for details.

Download Options:

1. mdbasic.d64 - A disk image that contains mdbasic.prg and a few testing/example programs & games
2. mdbasic.prg - The compiled executable program
3. mdbasic.crt - The cartridge image
4. mdbasic.asm - The source code

Download Turbo Assembler to compile source:
https://style64.org/file/TMPx_v1.1.0-STYLE.zip

See the shell script "compile.sh" for an example of how to compile using Turbo Assembler and execute on the VICE emulator.

MDBASIC can run on a C64 computer or any computer that uses the Versatile Commodore Emulator (VICE). VICE can attach the cartridge image (mdbasic.crt) or load & run the executable program (mdbasic.prg). VICE can also mount the disk image (mdbasic.d64). Refer to the VICE manual for details.

VICE can be downloaded using the following link:
http://vice-emu.sourceforge.net/

Example of loading & running MDBASIC as a program file:

READY.
LOAD"MDBASIC.PRG",8,1
 
SEARCHING FOR MDBASIC.PRG
LOADING
READY.
SYS64738

General Features:

* Displays memory address range after LOADing programs
* LOAD/SAVE directly to/from the text screen, bitmap or character definition memory
* SAVE specific memory address range using the SAVE command's alternate syntax
* Binary, Hexadecimal and Octal constant values in expressions
* 8 assignable function keys each with up to 15 characters
* Easily exit editor modes Quote, Insert & Reverse by pressing the Restore key
* Freeze LISTing by holding down the Shift key

Various Examples of statements (not a complete list; commands have many optional parameters):

Immediate Mode:

SAVE49152,53247,"HIRAM",8 :' BINARY SAVE OF 4K HIRAM
RUN "MYPRG",8             :' LOAD AND RUN MYPRG FROM DEVICE 8
RENUM 100,10              :' RENUMBER PRG START AT 100 INC BY 10
FILES                     :' LIST ALL FILES ON DEVICE 8
FILES"M*",9               :' LIST FILES STARTING WITH "M" ON DEVICE 9
DISK"S0:MYPRG"            :' ERASE FILE MYPRG ON DEVICE 8, DRIVE 0
KEY LIST                  :' DISPLAY FUNCTION KEY ASSIGNMENTS
KEY 2,"RUN"+CHR$(13)      :' ASSIGN FUNCTION KEY 2
DUMP LIST                 :' PRINT BASIC PROGRAM ON PRINTER
AUTO 10                   :' AUTO LINE NUMBERING INC BY 10
DELETE 150-170            :' DELETE PROGRAM LINES 150 TO 170 INCLUSIVELY
TRACE                     :' RUN PROGRAM WITH TRACE ENABLED

Program Mode:

0 STOP KEY OFF            :' DISABLE STOP KEY FROM CAUSING BREAK IN PROGRAM
1 STOP OFF                :' DISABLE ALL STOP STATEMENTS
2 SCREEN CLR              :' CLEAR CURRENT SCREEN
3 VOICE CLR               :' CLEAR SID REGISTERS
4 KEY CLR                 :' CLEAR KEYBOARD BUFFER
5 ERR CLR                 :' CLEAR LAST ERROR STATE
6 CURSOR CLR              :' CLEAR CURRENT CURSOR LINE
7 TIME CLR                :' RESET REAL-TIME CLOCK TO 00:00:00 (12AM)
8 ON ERR GOTO 100         :' WHEN AN ERROR OCCURS GOTO LINE 100
9 SCREEN OFF:SCREEN ON    :' TURN DISPLAY OFF THEN BACK ON
10 DISK"V0",9,S$          :' VALIDATE DISK ON DEVICE 9, DRIVE 0 WITH STATUS IN S$
11 POKE 1024 TO 2023,1    :' POKE ADDRESS RANGE WITH VALUE 1
12 POKE1024TO49152,1000,5 :' COPY 1000 BYTES FROM 1024 TO 49152
13 SPRITE 0,1             :' MAKE SPRITE 0 VISIBLE
14 SPRITE 1,1,6,0,13,1,3  :' SPRITE 1 VISIBLE, BLUE, MC OFF, PTR 13, ABOVE FOREGND, FULL EXPAND
15 MOVE 0,50,24           :' PUT SPRITE 0 AT COORD 50,24
16 MOVE1 TO 159,99,50     :' SLIDE SPRITE 1 TO CENTER SCREEN AT SPEED 50
17 MOVE0,0,0TO511,255     :' MOVE SPRITE 0 FROM TOP LEFT TO BOTTOM RIGHT, SLOWEST SPEED
18 PLAYSPRITE0,92,99,5    :' ANIMATE SPRITE 0 WITH PTRS 92 TO 99 WITH 5 JIFFIES BETWEEN FRAMES
19 X = $C000: B=%10101010 :' HEX $, BINARY % AND OCTAL @ IN EXPRESSIONS
20 MAPCOL 2, 1            :' SELECT COLORS FOR HIRES BITMAP RED DOT, BLK BKGND
21 SCREEN CLR 5, 0        :' CLEAR BITMAP PAGE THEN SHOW IN HIRES MODE
22 MAPCOL 1, 2, 3, 0      :' SELECT COLORS FOR MULICOLOR BITMAP WHITE,RED,CYAN WITH BLACK BKGND
23 SCREEN 5, 1            :' SHOW BITMAP IN MULTICOLOR MODE
24 PLOT 160,100           :' PLOT A DOT USING CURRENT PLOT TYPE AND COLOR
25 PLOT 16,10,1,1         :' PLOT A WHITE DOT
26 PLOT 160,100,0         :' REMOVE A DOT
27 DRAW "R60,D55,L60,U55" :' DRAW A 60x55 RECTANGLE RELATIVE TO LAST PLOTTED POINT
30 CIRCLE 48,37,23,18     :' DRAW A CIRCLE CTR 48,37 X-SIZE 23, Y-SIZE 18
34 PAINT 48,27,1          :' FLOOD FILL INSIDE CIRCLE WITH WHITE COLOR
35 TEXT 0,0,"MARK"        :' TEXT ON BITMAP W/DEFAULT CHRSET & SIZING
36 DUMP SCREEN            :' PRINT CURRENT SCREEN TO PRINTER
37 DUMP"HELLO THERE"      :' PRINT EXPRESSION TO PRINTER
39 TEXT                   :' RESTORE SCREEN TO NORMAL C64 TEXT AND COLOR MODE
40 VOL 15                 :' SET VOLUME TO MAX
41 PLAY "AA#BB-CC#DD#F@"  :' PLAY NOTES IN BACKGROUND REPEATEDLY
42 PLAY OFF               :' TURN OFF BACKGROUND PLAY
43 PLAY "!ABC>ABC>ABC"    :' PLAY NOTES IN FOREGROUND GOING UP IN OCTAVE
44 ENVELOPE 1,0,0,15,0    :' SET VOICE 1 ATTACK/DECAY/SUSTAIN/RELEASE
45 FILTER 500, 15, 1      :' LOW PASS FILTER, CUTOFF=500Hz
46 VOICE 1,1000           :' SET VOICE 1 PITCH TO 1000HZ
47 WAVE 1,1,1             :' START ATTACK/DECAY/SUSTAIN CYCLE FOR VOICE 1 WITH TRIANGE WAVEFORM
48 WAIT 60                :' PAUSE FOR 60 JIFFIES (1 SEC)
49 WAVE 1,1,0             :' START RELEASE CYCLE FOR VOICE 1, TRIANGLE WAVEFORM
50 X1 = ROUND(0.125, 2)   :' X1 = 0.13
51 X2 = ROUND(121, -3)    :' X2 = 100
52 T$ = TRIM$(S$)         :' STRING WITH ALL LEADING & TRAILING SPACES REMOVED FROM S$
53 T = TRIM(N)            :' NUMBER WITH DECIMAL PORTION TRUNCATED FROM N
54 PRINT MOD(12,10)       :' DISPLAY THE REMAINDER (MODULO) OF 12/10 WHICH IS 2 (TWO TENTHS)
55 PRINT PTR(X1)          :' DISPLAY MEM LOC OF VAR X1
56 J = JOY(1)             :' VALUE OF JOYSTICK 1 OF 2
57 P = POT(1)             :' VALUE OF PADDLE 1 OF 4
58 PX=PEN(1):PY=PEN(2)    :' GET THE LAST LIGHT PEN X & Y COORDINATES
59 SWAP J,P               :' SWAP VALUES IN VARS J,P
60 CURSOR 10,5: PRINT"*"; :' POSITION CURSOR FOR PRINT
61 C% = INF(0)            :' PHYSICAL COLUMN OF CURSOR (0-39)
62 TIME$="00:00:00"       :' SET REAL-TIME CLOCK TO 12AM
63 T=TIME                 :' GET REAL-TIME CLOCK SECONDS SINCE MIDNIGHT ACCURATE TO 1/10 SECOND
64 T$=TIME$               :' GET REAL-TIME CLOCK TIME OF DAY STRING IN FORMAT HH:MM:SS
65 PRINT T$, T            :' DISPLAY TIME STRING AND NUM SECONDS SINCE MIDNIGHT
66 IF A THEN 100 ELSE 200 :' ELSE TO HANDLE FALSE CONDITION
70 I = INSTR(A$,".")      :' GET INDEX OF THE PERIOD IN STR, 0 IF MISSING
75 PRINT INSTR(2,"TEST THIS INSTR","IS") :' PRINT INDEX OF "IS" STARTING AT INDEX 2
81 KEY WAIT S$            :' WAIT FOR KEY IN BUFFER THEN GET AS STRING
82 KEY WAIT I%            ;' WAIT FOR KEY IN BUFFER THEN GET AS INT (ASCII)
83 KEY WAIT F             ; 'WAIT FOR KEY IN BUFFER THEN GET AS FLOAT (ASCII)
84 KEY"OK"                :' PUT KEYS IN KEYBOARD BUFFER
86 LINE INPUT A$          :' TAKE INPUT FROM KEYBOARD TILL ENTER KEY PRESSED
87 LINE INPUT#1,A$        :' READ LINE FROM FILE 1 TERMINATED BY CR
88 SCROLL 0,0 TO 39,24    :' SCROLL WHOLE SCREEN UP 1 CHAR, NO WRAPPING (DEFAULTS)
90 DESIGN NEW             :' COPIES CHARACTER SET FOR DESIGN MODE
91 DESIGN 1,0, 0,0,0,8,8,0,0,0 :' CHANGE "A" TO LOOK LIKE A CENTERED DOT
92 SCREEN 1               :' PAGES 1-4 CAN USE THE REDEFINED CHARS
93 PRINT"A":WAIT 120      :' DISPLAY CHAR THEN WAIT 200 JIFFIES
94 SCREEN 0               :' PAGE 0 IS NORMAL C64 TEXT MODE
96 SYS $FFD2,ASC("A")     :' CALL ML SUBROUTINE WITH OPTIONAL A,X,Y,P REGISTERS
99 RUN@"PROG2",8          :' LOAD AND RUN ANOTHER PROGRAM WITH MINIMAL SYS INIT
100 PRINT "ERROR #";ERR;" LINE #";ERRL
105 IF ERR = 20 THEN RESUME NEXT :' DIV BY 0, SKIP ERRORED STMT
110 IF ERR = 29 THEN RESUME 65   :' LOAD ERR, CONT AT LINE 65
115 IF ERR = 15 THEN RESUME      :' OVERFLOW, TRY STMT AGAIN
120 ERR 11                       :' INVOKE SYNTAX ERROR

Other Features:
MDBASIC supports numeric constants of base 2 (binary %), 8 (octal @) or 16 (hexadecimal $).
The functions VALB, VALO and VALH (respectively) convert strings of these number bases. The NOT expression short-hand is the exclamation point. REM (remark) short-hand is the apostrophe. See examples below:

B1 = %00001111     :'DECIMAL VALUE OF 15 FROM BINARY CONSTANT %00001111
B2 = VALB("1111")  :'DECIMAL VALUE OF 15 FROM BINARY STRING "1111"
SYS $C000,0        :'CALL TO ADDRESS 49152 WITH ACCUMULATOR LOADED WITH ZERO
H = VALH("C000")   :'DECIMAL VALUE OF 49152 FROM HEX STRING "C000"
O = @20            :'DECIMAL VALUE 16 FROM OCTAL CONSTANT @20
O = VALO("10")     :'DECIMAL VALUE 8 FROM OCTAL STRING "10"
X = !X             :'SAME AS X = NOT X

LOAD/SAVE Text Screen, Charset or Bitmap
MDBASIC has a predefined binary format for storing the text screen, redefined character set and bitmap graphics. For text and bitmap screens all color settings are included in the saved file. On load of a text or bitmap screen the change will automatically be displayed. After loading a character set the new font is shown by using the DESIGN ON command which then should be followed by SCREEN CLR since it is a different page that may not have been initialized. See examples below:

SAVE"SCREEN",8,16   :'SAVES ALL TEXT WITH COLOR FROM CURRENT TEXT SCREEN
SAVE"CHRSET",8,17   :'SAVES THE CURRENT DESIGN OF CHARACTERS ASSUMING DESIGN IS APPLIED
SAVE"BITMAP",8,18   :'SAVES CURRENT BITMAP IMAGE WITH COLOR MODE
LOAD"SCREEN",8,16   :'LOADS SAVED SCREEN TEXT AND COLOR INTO CURRENT SCREEN
LOAD"CHRSET",8,17   :'LOADS CUSTOM DEFINED CHARSET, NEEDS DESIGN ON TO SEE
LOAD"BITMAP",8,18   :'LOADS BITMAP IMAGE AND DISPLAYS IT