I have no idea how to write scripts... but I was able to figure out how to change the posted script into an "auto save" that just overwrites the open file every 5 minutes.
Code:
namespace eval asave {
# Autosave implementation
proc auto_save {ms} {
# if a model is loaded, save version, repeat after ms millisec
global unsaved_changes
global acfilename ;# last saved file name
if {$unsaved_changes} {
set orname $acfilename
set fname [file root $acfilename].ac
menu_save_last
set acfilename $orname
}
after $ms "eval asave::auto_save $ms"
}
asave::auto_save 300000 ;# 60000 = 1 minute.
# puts "Autosave start"
}