Tutorial 11
Drawing a line on the Graph Screen

Overview

This tutorial will show how to display a line on the graph. Compare the speed of an Asm program graphing the line to a TI-Basic program doing the same thing. You'll be surprised!

Programming

Follow along now, this is definetly not hard :)

#define B_CALL(xxxx)	rst 28h \ .dw xxxx	
#define B_JUMP(xxxx)	call 50h \ .dw xxxx		

_op1set3		=41a1h
_vertcmd		=48a9h

	.org	9D95h			

	B_CALL(_op1set3)		; Opl1 = 3	
	B_CALL(_vertcmd)		; Draw vertical line at Y = 3	
	ret			
.end			
END

As you can see, the line was drawn lighting quick, almost in a blink of an eye. That's the power, advantage, and speed of Asm! Op1-Op6 are floating point variables. It's called "OP1 to OP6" because it is used as 6 registers each 11 bytes in size. Therefore when you read documentation that refers to OP1, OP2, OP3, OP4, OP5 or OP6, what is meant is the 11-byte "register". The size of each of these registers is driven by the fact that the TI-83 Plus has a floating point number format of 9 bytes and any var name also can be formatted into at most 9 bytes. The 10th and 11th byte in each register is used during floating point math execution. Floating-point number and variable formats are explained in another section. Understanding the use of this area of RAM will expand your ability to use TI-83 system routines.

New Commands

op1set - Set op1 = 3
_vertcmd - Graph verticle line

Conclusion

We will get into more in depth graphing in v1.02. This tutorial was meant to introduce you to graphing.

Tutorial 12