Anyone remember FCC Regs on emissions was Tops10 disk quota quandary 1336

I take exception to some of Mark's statements, and disagree with others.

Mark Crispin:

Bottoms-10 was junk in 1964 when it was the PDP-6 monitor. Why do you think that MIT and BBN had to write their own operating systems?

John Sauter:

I think MIT and BBN wrote their own operating systems because they wanted to, not because they had to. One of the nice things about being a research-oriented insbreastution is that you get to do research. Rewriting the PDP-6 monitor didn't interest me, so at the Stanford AI lab we instead modified it to meet our needs. We slowly drifted away from DEC's monitor, but I always made an effort to keep our sources up to date with what DEC was doing, and there was some flow in the other direction also. Bill Weir's COMPIL cusp was written at Stanford and ported to Tops-10 by DEC. If you have ever used the DIR command you owe Bill.

Mark:

Even today, people talk about how various modules (SCNSER, disk service, etc.) were unmaintainable except by one person.

John:

I thought Bob Clements did a fine job with SCNSER. I had no trouble modifying it to do accounting at Sanders. I cannot deny that someone might have said that, but I would have to question that person's ability to understand PDP-10 buttembly language programs.

Mark:

At times, even The One Holy Person had problems. The "Tony in RH20 Land" story is a lesson, not on the design choices of the RH20 but rather the design choices in TOPS-10 which buttumed that all hardware worked the same way. The RH20 did not being treated like an RH10, and was brutal in its punishmnet of anyone who attempted to do so.

John:

Again I do not agree. I had a similar experience, on a smaller scale, when I was trying to program a communicatons controller. I am sorry that I do not remember the name of the device, but some details remain with me to this day. This was on 5-5 around 1973. The documentation for the device was scanty, but I was able to figure out, more or less, how to program it. Of course, my software didn't work, and I was at a loss to understand way. Not being a hardware person I got one of the field service technicians to help me look at the prints, and we discovered that you had to tell the device the value of the sync character by sending it out through the input register! With that additional bit of knowledge I was able to communicate.

Now that isn't a case of an unfamiliar device being unlike a familiar one, it was a blatant omission from the documentation. Without either the engineering drawings or personal access to the designer of the device, I would never have figured out how to program it.

Mark:

developers. Why did so many developers abandon TOPS-10 if TOPS-10 was so wonderful?

John:

You don't work on a system because it is wonderful, you work on it because it is your job. I have seen instruction set architectures come and go; you get used to it. Perhaps those developers left Tops-10 for the same reason I did: in 1978 I saw the handwriting on the wall and took an opportunity to move to VAX development. of my VAX experience, so I conclude, with hindsight, that it was a good move.