From 2d622afaeabfadf62daaccb7b51447812ad8143c Mon Sep 17 00:00:00 2001 From: tilleul Date: Wed, 19 May 2021 11:55:56 +0200 Subject: [PATCH] Create spc_ex.md --- applesoft/spc_ex.md | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 applesoft/spc_ex.md diff --git a/applesoft/spc_ex.md b/applesoft/spc_ex.md new file mode 100644 index 0000000..afa1243 --- /dev/null +++ b/applesoft/spc_ex.md @@ -0,0 +1,20 @@ +# Use SPC() to print any character ! +## Introduction +You know how `SPC()` can be used to PRINT a number of space characters. For example `PRINT SPC(10)` will print 10 space characters. + +Why didn't they allow to print something else than space characters ? It would have been interesting (?) to have the ability to repeat a sequence of any character. + +Maybe like `PRINT REPT("*",10)` would print 10 asterisks. + +But Applesoft does not provide such an instruction. So are we doomed to use `PRINT "**********"`? + +Here's a technique that will allow you to repeat any character, even in `FLASH` and `INVERSE` without using additional 6502 routines. + +## Discovery +Let's see something weird ... +At the Applesoft prompt, type `FLASH`. +Then `PRINT SPC(10)`. You should now see 10 flashing space characters. +Now, press `CTRL-BREAK`. This exits the "flash" mode (do no type `NORMAL` !!). +Type `PRINT SPC(10)` again. And ... + +WOW ! WHAT IS THAT ??