Re: [TUHS] What was your "Aha, Unix!" moment?

The year was 1986. Top Gun was in the theaters. Lionel Ritchie was belting out “Say you, say me” on serious overplay. I was working on the coolest machine I ever saw. The Motorola S290. Initially, we had System III and eventually System V. At the time, I learned MS DOS months before I was exposed to UNIX. I could not understand how a new small Motorola UNIX Super-microcomputer could have such an extensive set of documentation. I had to read these huge books to learn this same system could run computers from DEC and others. These UNIX books were so extensive and I found there were two ways to use UNIX: (1) sign on to the system at at work; or, (2) sign on to the system in my imagination. Both were equally as fun. The Motorola S290 had a small DPU tower called Data Processing Unit and several other similar shaped small towers linked by a SCSI bus that housed 5.25” devices of the day. This included 50MB hard disks, Wangtek Streaming Tape Drive. Yes! You could mount a streaming tape as a block device! It would “shoe shine” the tape heads if you “cd” into a formatted tape. It was not practical as a block device, but it worked. The Motorola S290 DPU ran a primary operating system called ISOS. It was UNIX like. But not UNIX. Boot disks had to have an ISOS partition and a UNIX partition. The Motorola S290 would first boot ISOS. Then, UNIX would start afterwards. ISOS has similar UNIX commands like “cd”, “ls”, and “ps” After working in a UNIX shell one day, I signed on to ISOS. I wanted to understand how UNIX integrated with ISOS. What blew my 1986 kid mind: After signing on to ISOS, I did a “ps” PID PPID ... COMMAND 123 2 “/UNIX” Aha UNIX! UNIX was a process running under ISOS! Bill Corcoran