[inforoots] ITS v. CTSS

[Les Earnest]

At 10:26 PM 11/15/2005, John C Green Jr  wrote:
>Along with GE 645 & Multics Project MAC also had DEC PDP-6 and ITS.

The PDP-6 and ITS were in the Artificial Intelligence Project and had 
nothing to do with Project MAC. In fact, ITS stood for "Incompatible 
Timesharing System", which was a slam on MAC's "Compatible 
Timesharing System" (CTSS).

Curiously, what CTSS was compatible with was and old IBM batch 
processing system in which users were identified by a combination of 
project and programmer numbers, with programmers supposedly being 
subordinate to projects. When DEC developed the first commercial 
timesharing system based the PDP-6, they adopted the same convention 
for user IDs.

However, the first thing we did at my lab (SAIL) when we got our 
PDP-6 was to hack the operating system so that both project and 
programmer could be alphanumeric (alas, only up to three characters 
each because of memory allocation limitations) and projects were made 
subordinate to programmers.

Nevertheless DEC's timesharing systems, continuing with TOPS-10, 
persisted in using numeric IDs and this was carried forward in 
commercial timesharing services such as Compuserve. Thus when 
Compuserve joined the Internet, all their users had to put up with 
ugly numeric IDs as their email addresses. In other words, an 
identification scheme developed in an old IBM batch processing system 
survived into the Internet age. Happily, it has now vanished.

My email ID, "les," dates back to the three character era, as do 
those of many of my colleagues from that period.

         -Les Earnest