Tutorial 16
Text Formatting (2) Small text

Overview
   
I've put this tutorial off about as long as I could already. It's time I write it down before I forget. This tutorial will cover displaying small text. Displaying small text is not that much different from displaying normal or inverse text, it's all about loading the right values into the right coordinates.

    First, you should know that the coordinates you will be using should be loaded into the X and Y values of the graph screen. They are Pencol and Penrow. How do you tell the difference from each? Well, think of Pencol as Pen Column (Y) and Penrow as Pen Row (X). Why load the coordinates to the graph screen? As you know, the text you can write on the graph screen using the text( is smaller than the text you can write at the home screen. So the coordinates must be loaded into the Penrow and Pencol values.

Programming
   
This program will display small text above normal size text. You'll only need to use Pencol in this program.

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

_ClrLCDFull             =4540h
_GrBufClr               =4BD0h
_VPutS          =4561h
PENCOL         =86D7h
CURROW	      =800Ch
CURCOL        =800Dh
_puts           =450Ah

.org 9D95h

  B_CALL(_clrLCDFull)           ;Clear the screen
  B_CALL(_GrBufClr)    	 ;Clear all values in the graph buffer
  ld hl,0000h           	;Load 0 to hl register
  ld (PENCOL),hl                   ;Load hl value to Pencol
  ld hl,str1                   	 ;Load text string
  B_CALL(_vputs)                ;Call for displaying text on graph screen
  ld hl,0001h          	 ;Same here, load 0 to hl register
  ld (CURROW),hl                ;Load hl value to normal text coordinate
  ld hl,0000h
  ld (CURCOL),hl
  ld hl,str2
  B_CALL(_puts)         ;Put text on homescreen
  ret
str1:                   ;Label for text
  .db "This is small writing.",0   ;Small text
str2:
  .db "This is big.     ",0     ;Normal text
.end
END

New Commands

_GrBufClr - Clears the values stored in the graph buffer
_Vputs - Call for displaying text on the Graph screen
Pencol - Column coordinate for graph screen
Penrow - Row column coordinate

Conclusion
   
Well, what a great way to kick off the new version of this help file. This version fixes bugs, adds new information to the existing tutorials, and includes brand new tutorials.

Tutorial 17

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