Another OS/8 trivia question

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5 total messages Started by Kerry Kurasaki Mon, 12 Oct 1992 18:28

#39

Author: Kerry Kurasaki
Date: Mon, 12 Oct 1992 18:28

4 lines
591 bytes

Wow!  Some pretty sharp netters out there.  Here's another one:

Anyone know how OS/8 knows if batch is running?  That is, how does
KMON know to get stuff from the file instead of the keyboard?

Re: Another OS/8 trivia question

#41

Author: Steven L. Johnson
Date: Tue, 13 Oct 1992 03:26

10 lines
877 bytes

kerry@Ingres.COM (Kerry Kurasaki) writes:

>Anyone know how OS/8 knows if batch is running?  That is, how does
>KMON know to get stuff from the file instead of the keyboard?

By looking at location 7777 in field 0.  Actually I knew it
was someplace in the last few words of field 0, but had to look
it up to remember which one.

-Steve "been a few years since I wrote disk drivers for OS/8"

Re: Another OS/8 trivia question

#43

Author: Kerry Kurasaki
Date: Tue, 13 Oct 1992 17:13

16 lines
1044 bytes

In article <1992Oct13.032611.7348@tigger.jvnc.net> johnson@tigger.jvnc.net (Steven L. Johnson) writes:
>
>>Anyone know how OS/8 knows if batch is running?  That is, how does
>>KMON know to get stuff from the file instead of the keyboard?
>
>By looking at location 7777 in field 0.  Actually I knew it
>was someplace in the last few words of field 0, but had to look
>it up to remember which one.
>

And the bonus question:

	What should the value be at that location and what is the
	significance of that value?

Gee, you guys ARE good!

Re: Another OS/8 trivia question

#45

Author: Charles Lasner
Date: Tue, 13 Oct 1992 19:47

25 lines
1662 bytes

In article <1992Oct13.171324.3141@pony.Ingres.COM> kerry@Ingres.COM (Kerry Kurasaki) writes:

>
>And the bonus question:
>
>	What should the value be at that location and what is the
>	significance of that value?
>
>Gee, you guys ARE good!

If bit[0] of 07777 is a one, batch is running.  If you want to interact with
it, the source of the BAT handler is useful info for this.  Look in the PDP-8
archives for it on ftp.telebit.com where it is or will be soon.

Bits[6-8] are the software core size where 000 and 111 both mean 32K is
available because they both mean the highest field available is 7.

Bits[3-4] are the date base group year bits currently, where each increment
is 8 years starting at 1970-77 going to 1994-2001.  Since it's getting
close to the end of the world, I want a definition for all the bits so I
can at least double the lifetime, if not quadruple it.  So please find me
a bit or two, preferably in that word.  Anyone know what all of the other
6 bits mean?

cjl

Re: Another OS/8 trivia question

#49

Author: Kerry Kurasaki
Date: Tue, 13 Oct 1992 23:19

15 lines
1338 bytes

In article <1992Oct13.194705.6091@news.columbia.edu> lasner@watsun.cc.columbia.edu (Charles Lasner) writes:
>>
>>And the bonus question:
>>
>>	What should the value be at that location and what is the
>>	significance of that value?
>>
>If bit[0] of 07777 is a one, batch is running.  If you want to interact with
>it, the source of the BAT handler is useful info for this.  Look in the PDP-8
>archives for it on ftp.telebit.com where it is or will be soon.
>
Actually, there is an additional check made to ensure that Batch was not
corrupted/overwritten.  It's been a looooooong time, but there is a magic
value in ??? location 0200 ??? in the batch field.  What is that value
and what is the significance of it?

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