Feb. 7, 1981
"This letter talks about the Inkey command and aabout cursor control for the Apple 1 computer. Also the statement is made that they was preparing for the Apple II back in 1976 the way the software, Basic looked."
Feb 7, 1981
Boy, I'll be glad when winter is over. It
seems like it lasts forever, only more.
MURPHY'S LAW strikes again!! That
program I sent you has an error at 0311 -
change F8 to F5. You couldn't trace it
because TRACE hangs up waiting for the PIA
to clear, and loops endlessly, but it (the program) should
work correctly. (unless more gremlins got into
INKEY IS SURE O.K.! (Hint, change
20H (JSR) to 4CH(JMP) at E86F, EE43, EE57
and EE5C. JMP is faster than JSR and doesn't
push the return address on the stack. I don't
know if it would happen, but the stack could
overflow on a large BASIC program and wipe
out the game.)
You asked about curosr control - - -
(Print AT, etc.) JOBS, WOZNIAK and COMPANY
made the Apple I with NO way to control
the cursor. That's the biggest difference between
Apple I and Apple II. They used dynamic
shift registers (1K storage - 2504's) to hold
the characters for display, giving us a first-in-
first-out stock in hardware. No way to
change a character, blank or move the cursor,
clear the screen, or add clusters except at
the end of the list. Some BASIC commands of
ours change the vertical cursor pointer, etc.
but since the video isn't in RAM, nothing
happens. (They were preparing for Apple II
back in '76). Our advantage, of course, is
another Kilobyte of RAM free for our use,
plus less overhead in our MONITOR.
Still no keyboard. I can't see paying
80 to 200 bucks at this time for a keyboard
when 16K of RAM is $29. Well, maybe something
will turn up, - I'll let you know when I'm up
and running again.
Oops! I've missed the mailman. -
I'd better get this letter in an envelope or
you'll never get it. - Write when you can.