One (Ctrl-S) of Those (Ctrl-S) Days

Don’t know what I did but suddenly happy mac was question-mark-the-diskette-ian and i don’t seem to have a “startup cd” for this system. i used the os x install cd which forced a new installation (possibly a step down from an update i dimly recall installing?). but it worked, here i am, back again, furiously backing up my crucial work, including chapter 30 which is now two days late on my impossible schedule.