[TUHS] Re: A re-analysis of some DECtapes from dmr

[TUHS] Re: A re-analysis of some DECtapes from dmr

[Noel Chiappa]

    > From: Yufeng Gao

    > This version of UNIX appears to be between V1 and V2

It's too bad it's not 'between V2 and V3', since the UNIX kernels V2 and V3
are missing. (V4 is the earlist one that we have, after the V2 and onward gap.)

So, depending on how far from V1 (which we have) it is, it _might_ be worth
dis-assenbling. It would be particularly worth having it if it suppports the
KS11, since almost no documentation of that has survived; code that uses it
would allow re-creation of a programming manual for it.

    > From: Lars Brinkhoff

    > Is the kernel for a PDP-11/20 or /45? 

I don't think it can be the /45; as of V2, the /45 was apparently expected in
the near future, and this was before the V2.

	Noel

[TUHS] Re: A re-analysis of some DECtapes from dmr

[Warren Toomey via TUHS]

On Sat, Dec 07, 2024 at 09:32:58AM +0000, Lars Brinkhoff wrote:
> Is the kernel for a PDP-11/20 or /45?  If /20, does it use the KS11 for
> memory mapping?

Lars, it's the same kernel as in this project:
https://github.com/DoctorWkt/unix-jun72

Here's part of the SimH config:

set cpu 11/20
set cpu 32K
set rk0 enabled
set rf enabled
set tc enabled
set tc enabled
set rf enabled
set ke enabled
set dci en

Cheers, Warren

[TUHS] Re: A re-analysis of some DECtapes from dmr

[Lars Brinkhoff]

Is the kernel for a PDP-11/20 or /45?  If /20, does it use the KS11 for
memory mapping?

[TUHS] Re: A re-analysis of some DECtapes from dmr

[Warren Toomey via TUHS]

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On 7/12/24 08:58, Warren Toomey via TUHS wrote:
> All, I received this detailed e-mail from Yufeng Gao who has done a great
> job at analysing some of the DECtapes that Dennis made available to the
> Unix Archive.P.S. I have a follow-up e-mail coming ...

Here is a follow-up e-mail from Yufeng, I just needed to ensure the 
colours got preserved :-)

Cheers, Warren

---- From Yufeng Gao ----

If you're going to share my email, please consider adding the following 
information about the s1 and s2 files being from the same version of UNIX:

"The maki.s source and a.out executable found in /usr/sys is the exact 
same maki program used to create the INIT tape, judging by the 
unzeroed/leftover bytes at the end of vcboot."

And the row highlighted in green from the following table to the one 
from my last email:

                | UNIX V1  | s1    | UNIX V2

----------------------+----------+-------+---------

Warm boot             | [1]73700 | ???   | ???

Cold boot             | 1        | 1     | 1

Unassigned 3K prog    | 2        | 2     |

Dump core & halt      | 10       | 10    | 10

Boot from RK          |          | 20    | 20

Dump core & warm boot |          | 40    | 40

Boot from paper tape  | 0        | 0     | 0

Load DEC loaders      | 57500    | 57500 | 77500

----------------------+----------+-------+---------

*BOS load address      | 54000    | 54000 | 154000*

UNIX load address     | 400      | 400   | 600

----------------------+----------+-------+---------

Sorry if I sound like I'm asking for too much, the history is quite 
important so I want everything to be in the best possible state :).

Sincerely,

Yufeng Gao

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