On Fri, 2008-10-24 at 18:09 -0700, Bill Campbell wrote: > The Burroughs Medium Systems mainframes I worked on allowed one to store > the program on disk, then compile with modifications in a card deck, using > the sequence numbers to replace or insert lines from the cards. There were > options to create a new disk file with the patches included, and to > resquence the source on disk. Typically there were several card desks in a > drawer which could be loaded to recreate the patched disk file by loading > them in sequence which was fine until the disk file was resequenced when it > was time to punch new cards from the disk file to replace the original deck > and patches. Punch cards were far more reliable backup than mag tape and > in a pinch one could read the printing on the card to fix a badly damaged > card (it was amazing how fast a card reader jam could turn the first card > into an accordian fold). Then came CANDE, TD8xx terminals, and editing on your head-per-track disk. Ah for the good old days, when men were men, and memory upgrades involved fork lifts. Dave