Based on Microsoft Basic for 6502. Forked from this repo.

This sources tree targets only to Cerberus 2100 and 2080 computers.

I'm standing on shoulders of titans. Some code possibly acquired from public resources.

• RAM test will check memory from RAMSTART2 up to RAMEND.

• Token table was extended. My article about this modification

• PAUSE n - pauses execution for n-frames(not more than 256)

• RESET - reboots computer

• FILES - lists current directory

• LOAD "filename" - load program from disk

• SAVE "filename" - stores program to disk

• KILL "filename" - deletes file on disk

• BLOAD "filename",addr - load binary file to specified address of memory

• BSAVE "filename",addr,len - save memory dump to disk from specified address with specified lenght

• SYS addr - call routine in machine code with specified address

• KEY$(n) function - reads key if zero - non blocking. For example

    10 A$=KEY$(0)
    20 IF A$="" THEN GOTO 10
    30 PRINT "YOU PRESSED: "; A$

or

    10 PRINT "YOU PRESSED: ";KEY$(1)

Letters will be always uppercased.

• CLS - clear screen

• LOCATE COL, ROW - move cursor to specified point. Example:

   10 CLS
   20 LOCATE 10,10
   30 PRINT "Hello!"

• Updated command POS(n), when N is zero will be returned current COL else ROW. Example:

   10 LOCATE 13, 11
   20 x = POS(1) : y = POS(0)
   30 CLS
   50 PRINT "X=";STR$(x);" Y=";STR$(y)

• SOUND lenght, freq - plays sounds

• PSET X, Y - draw low resolution graphics point.

• LINE x1,y1,x2,y2 - draw line connecting two specified points

• CIRCLE x,y,r - draw circle with center at X,Y and raduis R

User defined graphics that allows use 47(from 1 to 47, zero is empty tile) tiles on screen.

• TILEDEF n,b1,b2,b3,b4,b5,b6,b7,b8 - define tile with number N and bitmap bytes specified by b1..b8

• TILE x,y,n - draw tile N with coordinates X and Y

CC65 compiler suite is required.

make.sh build script will make everything that required for building version.

I've designed font for usage with Cerberus basic:

It have same license that my code - 2-clause BSD.

Feel free to use it in your projects.

More information on the differences of the respective versions can be found on this blog entry: Create your own Version of Microsoft BASIC for 6502.

2-clause BSD