[4174] in Central_America
Re: New quotes for Sun Mar 22
sethg@ATHENA.MIT.EDU (sethg@ATHENA.MIT.EDU)
Sun Mar 22 09:57:26 1992
*I* remember some of this stuff, and now *I'm* worried.
> 1] What is 20 ED FD? 20 0C FD? 4C 59 FF? 60?
20 ED FD calls the single-character output subroutine.
20 0C FD probably calls some related subroutine.
4C is the "JMP" command: I don't remember what is at memory location $FF59.
Maybe the monitor program?
60 is the "RTS" (return from subroutine) command ... right?
2] Name 3 ways to reboot the computer at the machine language prompt
in 5 characters or less
"6 CTRL-P RETURN" ... and ... uh ...
> 5] Whats the POKE to click the speaker?
"POKE (-16336,0)" clicks the speaker twice.
> 7] Where are the sector locations for the catalog track(s)?
Track 17, starting at Sector 0.
> 8] What are the sector locations for the DOS tracks?
Tracks 0 through 2.
> 9] Whats memory bank switching and why is it important relating to
the Plus?
Bank switching makes different physical RAM chips map onto the same logical
memory addresses at the same time. It's important because the 6502 could
only address 64K, and in order to have 64K of accessible RAM, the machine
needed a way to switch out the ROM and the space allocated to devices.
