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7
applesoft/spc/README.md
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@ -37,7 +37,7 @@ To understand what's happening here, you need to know how characters are printed
The Applesoft general routine to print characters on screen is in `$DB5C` and is named `OUTDO`. The Applesoft general routine to print characters on screen is in `$DB5C` and is named `OUTDO`.
Here's the routine, taken from [S-C documentor website](http://www.txbobsc.com/scsc/scdocumentor/). Here's the routine, taken from [S-C documentor website](http://www.txbobsc.com/scsc/scdocumentor/).
```assembly
1950 * PRINT CHAR FROM (A) 1950 * PRINT CHAR FROM (A)
1960 * 1960 *
1970 * NOTE: POKE 243,32 ($20 IN $F3) WILL CONVERT 1970 * NOTE: POKE 243,32 ($20 IN $F3) WILL CONVERT
@ -55,7 +55,7 @@ Here's the routine, taken from [S-C documentor website](http://www.txbobsc.com/s
DB6C- 20 A8 FC 2090 JSR MON.WAIT SO SPEED=255 BECOMES (A)=1 DB6C- 20 A8 FC 2090 JSR MON.WAIT SO SPEED=255 BECOMES (A)=1
DB6F- 68 2100 PLA DB6F- 68 2100 PLA
DB70- 60 2110 RTS DB70- 60 2110 RTS
```
The routine is called with the accumulator containing the character to print every time Applesoft needs to print something (like when using `PRINT` or `INPUT` or ... `SPC` !) The routine is called with the accumulator containing the character to print every time Applesoft needs to print something (like when using `PRINT` or `INPUT` or ... `SPC` !)
The routine that will effectively print the character on screen is `COUT` (in `$FDED`here named `MON.COUT`) but the `OUTDO` routine here is the pre-treatment of the character to print. The routine that will effectively print the character on screen is `COUT` (in `$FDED`here named `MON.COUT`) but the `OUTDO` routine here is the pre-treatment of the character to print.
@ -139,7 +139,7 @@ Remember that not all characters are printable in FLASH or INVERSE.
This little program will demonstrate what we learned here. This little program will demonstrate what we learned here.
It will fill the screen with one kind of character, using four `SPC` statements with a parameter of 240. It will fill the screen with one kind of character, using four `SPC` statements with a parameter of 240.
```basic
10 HOME 10 HOME
20 X = 255: Y=0: REM INIT VALUES 20 X = 255: Y=0: REM INIT VALUES
30 POKE 243,0: REM RESET ORA MASK 30 POKE 243,0: REM RESET ORA MASK
@ -159,6 +159,7 @@ It will fill the screen with one kind of character, using four `SPC` statements
170 PRINT SPC(240) 170 PRINT SPC(240)
180 PRINT SPC(240) 180 PRINT SPC(240)
190 GOTO 20 190 GOTO 20
```
<img src="spc6.png"> <img src="spc6.png">
# HAPPY CODING ! # HAPPY CODING !