F38E
to F530 |
Various routines used by the assembler.
F399 - separate label, separator(;), and REMs (/).
F3F2 - separate immediate (@), indirect( () ), and
accumulator mnemonics.
F454 - act on immediate mode (@).
F462 - act on indirect mode (()).
F49B - act on accumulator commands (e.g. ROL A).
F511 - print "OUT OF RANGE".
F514 - the string "OUT OF RANGE". |
F531
to F541 |
Carries out the OLD command. Exits to
END at CD9B. |
F542
to F641 |
Carries out MOVE, DRAW, and PLOT
commands.
F542 - entry point for MOVE
F546 - entry point for DRAW
F54E - entry point for PLOT |
F644
to F67A |
Subroutines used by MOVE, DRAW, and
PLOT.
F668 - decrement the vector (5A),X.
F671 - increment the vector (5A),X.
F678 - plot point subroutine ( JMP(3FE) ). 3FE/3FF
depends on the mode set by the CLEAR command (see below). |
F67B
to F6CF |
Carries out the CLEAR command. This sets
up the word at B000 for the CRT controller, and places
the appropriate point plot routine address in 3FE/3FF. |
F6C2
to F6CF |
Carries out CLEAR 0. |
F6CF
to F6E1 |
Graphics mode control data, including
appropriate clear mode and point control routine
addresses, and CRT controller words for B000 (port
control from PIA). |
F6E2
to F7C8 |
Point PLOT subroutines used by MOVE,
DRAW, PLOT.
It requires the X co-ordinate in 5A,5B; the Y co-ordinate
in 5C,5D; 5E=0 clears point, 5E=1 sets the point and 5E=2
inverts the point. Entry points are:MODE ADDRESS
0 F6E2
1 F73B
2 F754
3 F76D
4 F7AA
|
F7C9
to F7D0 |
Data used by point plot routines at F6E2
et. al. |
F7D1
to F7EB |
A subroutine that is useful for printing
from your own machine code program. When this routine is
called, all bytes after the call are considered to be
ASCII code, which is outputted to the screen. The routine
will terminate back to your machine code program when it
encounters a negative number (NOP is a good one). See
example of use in chapter 6. |