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Re: help diagnosing an Apple IIe, please.



John B. Matthews wrote:
In article <52bcece6-7077-4ded-8858-2f1218d727b6@q30g2000prq.googlegroups.com>,
 adric22 <adric22@yahoo.com> wrote:

[...]

Well I'm an old school C64 programmer, so let me ask you this.  How do
you write a program in BASIC that continues to loop and do stuff while
waiting for a keypress?  For example, I was trying to write a simple
drawing program for the low-res graphics mode and I wanted it to blink
the pixel it was currently sitting on when no keys were being
pressed.  How would I achieve this?  On the C64 we would use a command
like this:

10 GET A$: IF A$ = "" THEN GOTO 10

That would achieve the same thing as the GET statement alone achieves
on the Apple, but I could remove that GOTO 10, and put it at the end
of several other commands.. That way those commands would continue to
execute until something was pressed.


Maybe something like this?

10  HOME :A$ = " ": ONERR  GOTO 90
20  PRINT "Press any key; ^C exits."
30  KB = -16384 : KC = KB +16
40  IF PEEK(KB) >  128 THEN POKE KC,0 : A$ = CHR$(PEEK(KB))
50  VTAB 12: PRINT ">  ";A$
60  VTAB 12: PRINT "-> ";A$
70  VTAB 12: PRINT "-->";A$
80  GOTO 30
90  END

You can also GET the key after determining that one has
been pressed:

40 IF PEEK(KB)>127 THEN GET A$

-michael

NadaNet and AppleCrate II: parallel computing for Apple II computers!
Home page: http://home.comcast.net/~mjmahon

"The wastebasket is our most important design
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