Subject: Another OS/8 trivia question

From: [email-masked] (Kerry Kurasaki)
Date: 12 Oct 92 18:28:40 GMT

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?

---

From: [email-masked] (Steven L. Johnson)
Date: Tue, 13 Oct 1992 03:26:11 GMT

>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"

---

From: [email-masked] (Kerry Kurasaki)
Date: 13 Oct 92 17:13:24 GMT

>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!

---

From: [email-masked] (Charles Lasner)
Date: Tue, 13 Oct 1992 19:47:05 GMT

>	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.

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

---

From: [email-masked] (Kerry Kurasaki)
Date: 13 Oct 92 23:19:16 GMT

>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?