On 03/21/2016 11:31 AM, Lew Wolfgang wrote:
On 03/21/2016 08:10 AM, Dave Howorth wrote:
On 2016-03-20 20:25, Anton Aylward wrote:
In the days of the TTY a single user UNIX would give priority to keybaord interrupts, and in the return from the interrupt the scheduler would let the process blocked waiting for the keystroke (an editor perhaps) wake up and process the input.
Those days are long gone. By the time the Consent Decree let UNIX source be available and ported to the early 16-bit micros UNIX was already doing a lot of multi-tasking.
I'm not sure what you meant here. It seems to imply there was a time when UNIX was not multitasking, let alone multiuser. When was that?
Even UNICS was multiprocessing, wasn't it?
I'm not sure about UNICS, but UNIX was multi-user/multi-tasking right from the start, as far as I know. My first experience was with SysV-R2 in the early 1980's, if memory serves, and it supported multiple users via RS-232 connected CRT's. It was even real-time (MASSCOMP) and had a bank of A/D and D/A converters.
The Consent Decree released the V7 code to many developers. There was a flood of small firms porting it to microprocessor in the mid to late 1970s. Along with this there was rapid development at Berkeley and the availability of the VAX. And of course Bill Joy. The 'ownership' of the code changed within bell to the "Unix Systems Group" and they responded with development in a number of areas, not all of which the founders would have approved of. They, of course, went their own way. USG rapidly moved though SYS III; IV seems to have been skipped, I never say it. When SYS V came out USG said there would never be a SYS VI, so I got my custom licence plates - "UNIX V". I started working as a user at university on UNIX V5 on the language development, parsers and interpreters. After graduating I worked as an application developer and later kernel hacker on V6, V7 and backed merged SYS III features into the network enabled HCR XENIX which was - mostly - a V7 code base. That was horrendous!. I later worked on the kernel and some applications of SYSV though to SVR4. Many of the USG implementations of the Berkeley equivalent tools were very bad examples of coding! I remember in particular the morass of spaghetti that was USG's "more'. One of the principles that Brian and the other Founders insisted on was a degree of remote device agnosticism, and the guys at Berkeley picked up on that. The early UNIX implementations had just one KSR-33 :-) In 1975 Ken Thompson took a sabbatical to Berkeley and installed UNIX V6 there. This produced the 'fork' of UNIX that became known as "BSD". Berkeley, being a university, wanted to use a lot of non-standard, non-DEC equipment, and wrote many more drivers for these. Part of the agnosticism was to be able to hang any vendor's "Glass TTY" of not only the DEC serial drivers but any 3rd party units or even ones they had built themselves. So we got "Termcap". Eventually we got "terminfo"! Meanwhile, back at Bell, early graphic terminal were in use and they too made use of the serial protocols. Eventually even MIT X-Windows System used serial lines. I recall using X terminals in the 'terminal room' at USENIX and other meet-ups in the late 1980s. Cue "Those were the days ..." -- A: Yes. > Q: Are you sure? >> A: Because it reverses the logical flow of conversation. >>> Q: Why is top posting frowned upon? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org