Save this script as auto_save.tcl in <ac3d_dir>/scripts.
Code:
namespace eval asave {
# Autosave implementation
variable nsave 0 ;# count number of saves for file name.
proc auto_save {ms} {
# if a model is loaded, save version N, repeat after ms millisec
global nsave
global unsaved_changes
global acfilename ;# last saved file name
if {$unsaved_changes} {
incr nsave
set orname $acfilename
set fname [file root $acfilename]_${nsave}.ac
puts "Save $nsave as $fname"
set acfilename $fname
menu_save_last
set acfilename $orname
}
after $ms "eval asave::auto_save $ms"
}
asave::auto_save 60000 ;# 60000 = 1 minute.
# puts "Autosave start"
}
to automatically save your current file as <orignal name>_1.ac and so on.
Will only make a backup if a change is detected (the changes which cause 'changes made do you want to save' on Exit). Makes a save every minute if there is a change; replace 60000 with 10000 if you want to fill up your disk quickly.