FJ
ÔO INVOKE ANY OF THE COMMANDS USE:

  ÓÙÓ 4112, Î1 [ ,Î2 [ ,Î3 [ ,Î4 ]

Î1 IS THE COMMAND NUMBER. Î2 THRU Î4 
DEPEND UPON THE COMMAND REQUIRED, AND 
SERVE DIFFERENT FUNCTIONS.
Î2 THRU Î4 WILL BE SET TO EQUAL ZERO 
IF NOT FOUND ON THE LINE.

ÔHE COMMANDS AVAILABLE FOR THE VALUES 
OF Î1 ARE AS FOLLOWS ("--" INDICATES 
PARAMETER UNUSED):


ÎAME   Î1  Î2  Î3  Î4   ÕSE

ÉÎÉÔÇÒ  0  --  --  --   ÓET WINDOW 0 
TO FULL SCREEN SIZE.

ÌÉÎÅÔÏ  1   Ø   Ù  --   ÄRAW A LINE 
FROM CURRENT COORDS TO Ø,Ù. ×ITHIN 
SELECTED WINDOW.

ÓÅÔ×ÉÎ  2   Ø   Ù   Î   ÄEFINE WINDOW 
Î. ÃURRENT COORDS TOP LEFT. Ø,Ù BOTTOM 
RIGHT. ÁLL COORDS ABSOLUTE TO SCREEN.

ÓÅÌ×ÉÎ  3   à   Æ   Î   ÓELECT WINDOW 
Î FOR PLOTTING. ÐLOTTING IN COLOUR Ã, 
WITH PLOTTING FUNCTION TYPE Æ.

ÐÌÏÔ    4   Ø   Ù  --   ÐLOT A DOT AT 
Ø,Ù WITHIN SELECTED WINDOW.

ÃÌÅÁÒ×  5  --  --  --   ÃLEAR SELECTED 
WINDOW. ÉF PLOT FUNCTION IS ÅÏÒ THEN 
WINDOW IS FILLED.

ÃÌÅÁÒÓ  6   Î  --  --   ÃLEAR WINDOW 
Î.

ÍÏÖÅÔÏ  7   Ø   Ù  --   ÍOVE TO COORDS 
Ø,Ù FOR SUBSEQUENT FUNCTION.

ÓÁÖÅÃ   8  --  --  --   ÓAVE COORDS 
FOR SELECTED WINDOW.

ÌÏÁÄÃ   9  --  --  --   ÌOAD COORDS 
FOR SELECTED WINDOW.

ÓÅÔÆÕÎ 10   Æ  --  --   ÐLOTTING 
FUNCTION BECOMES TYPE Æ.

ÓÃÒÅÅÎ 11   Ó   Â  --   ÓCREEN COLOUR 
BECOMES Ó. ÂORDER COLOUR BECOMES Â.

ÐÌÏÔÓ  12  --  --  --   ÐLOT DOT AT 
CURRENT COORDS.

ÔÅØÔ   13  ÌÂ  ÈÂ  --   ÄRAW STANDARD 
TEXT CHARACTERS AT COORDS. ÌÂ,ÈÂ ARE 
LOW/HIGH BYTE ADDRESS OF DATA (DATA 
MUST TERMINATE WITH ZERO BYTE).

ÄÒÁ×ÔØ 14  Ì  È  ÄÆ   ÄRAW LARGE 
TEXT CHARACTERS AT COORDS. ÌÂ,ÈÂ ARE 
LOW/HIGH BYTE ADDRESS OF DATA (DATA 
MUST TERMINATE WITH ZERO BYTE). ÄÆ IS 
THE DRAWING FUNCTION.

ÂÏØ    15   Ø   Ù  --   ÄRAW A BOX 
FROM COORDS (TOP LEFT) THRU Ø,Ù 
(BOTTOM RIGHT) BACK TO COORDS.

ÃÏÌÏÕÒ 16   Ã  --  --   ÐLOTTING 
COLOUR BECOMES Ã.

ÄÒÁ×ÃÈ 17   Ä  ÄÆ  --   ÄRAW LARGE 
CHARACTER CODE Ä, USING DRAWING 
FUNCTION ÄÆ.

ÒÅÁÄ   18   Ø   Ù  --   ÒEAD POINT AT 
POSITION Ø,Ù. ÌOCATION $07Æ2 HOLDS 
RESULT.

ÃÓÅÔ   19  ÃÂ  --  --   ÃHARACTER BASE 
HIGH BYTE BECOMES ÃÂ. ÕSED IN DRAWING 
LARGE CHARACTERS.

ÉÎÖÅÒ× 20  --  --  --   ÉNVERT (PIXEL 
WISE) SELECTED WINDOW.

ÉÎÖÅÒÎ 21   Î  --  --   ÉNVERT (PIXEL WISE) WINDOW NUMBER Î.

ÏÌÄ    22  --  --  --   ÐERFORM ÏÌÄ FUNCTION. ÉÅ. ÒEVERSE OF ÎÅ× ON ÂÁÓÉà PROGRAM.




ÃOMMAND NOTES:

×INDOWS:

ÕP TO EIGHT WINDOWS MAY BE DEFINED (0 THRU 7). ÐLOTTING WITHIN SELECTED WINDOW IS RELATIVE TO WINDOW TOP LEFT POSITION. ÉÅ. 0,0 IS AT TOP LEFT OF SELECTED WINDOW. ÃOORDS OUTSIDE SELECTED WINDOW ARE IGNORED.


ÐLOTTING FUNCTION Æ:

0    -   SET DOT.
128  -   RESET DOT.
64   -   FLIP DOT. (ÅÏÒ).


ÄRAWING  FUNCTION ÄÆ: 

0    -   AS PLOTTING FUNCTION USING SET ONLY BITS IN MATRIX.
64   -   USE REVERSE OF MATRIX.
128  -   DRAWN AS MATRIX (SET AND RESET BITS).
192  -   COMBINATION OF ABOVE TWO.

ÁDD 1 TO THE ABOVE FOR TEXT DRAWN DOWNWARDS, ELSE IT'S DRAWN LEFT TO RIGHT IN ÄÒÁ×ÔØ.


ÒEAD RESULT IN $07Æ2 (DECIMAL 2034):

ÅQUALS ZERO IF DOT IS RESET.
ÅQUALS 128 IF NON DOT CHARACTER (TEXT).
ÅLSE INDICATES DOT IS SET.

ÔO READ OUTSIDE WINDOW LIMITS RESULTS IN ZERO (SO MAKE SURE YOU DON'T!).


ÃHARACTER BASE:

ÅÇ. ÉF YOU SET THE CHARACTER BASE TO 63, AND STORE YOUR CHARACTER MATRIX AT 16128 (256*63) TO 16135. ÙOU MAY DRAW IT USING CODE 0.



ÍACHINE CODE COMMAND ACCESS:

ÁLL REGISTERS ARE ALTERED BY THE ROUTINES. ÅXCEPT ÐÌÏÔÓ WHICH DOESN'T ALTER THE Ø AND Ù REGISTERS.

ÒEAD FUNCTION RETURNS RESULT IN Á REGISTER.
 
Î2,Î3,Î4 IN ALL COMMANDS APPLY TO REGISTERS Ø,Ù AND Á, RESPECTIVELY.

ÃOMMAND EXECUTION ADDRESSES ARE STORED IN A TABLE AT ADDRESS $1016. ÉN FORM:

$1016: LOW  BYTE
$1017: HIGH BYTE OF COMMAND 0.
$1018: LOW  BYTE
$1019: HIGH BYTE OF COMMAND 1.

ETC.

ÅXAMPLE MACHINE CODE USE:

 .
 .
 ÌÄØ #$05
 ÌÄÙ #$05
 ÊÓÒ ÌÉÎÅÔÏ; DRAW TO Ø,Ù
 .
 .

ÉÎÉÔÇÒ: ÊÍÐ