[Simh] Getting rsxs to run on the pdp11 emulator

[Johnny Billquist]

On 2015-03-03 22:40, Rhialto wrote:
> On Tue 03 Mar 2015 at 22:08:29 +0100, Johnny Billquist wrote:
>>> attach tm0 BB-J0830-01.M01_RSX11M+_V4.6_1999.tap
>>
>> This would be the full system.
>>
>>> attach tm1 BB-J0830-01.L01_RSX11M+_V4.6_BRU_1999.tap
>>
>> This is slightly weird, as the normal RSX distribution of V4.6 is just one
>> tape that holds both BRUSYS and the distribution.
>
> Hm weird, since going by the file sizes, the L file is the larger one,
> and not bootable.

Weird stuff indeed.

>   11M  BB-J0830-01.M01_RSX11M+_V4.6_1999.tap     <-- booted off this one
>   30M  BB-J0830-01.L01_RSX11M+_V4.6_BRU_1999.tap <-- contains the string
>        ***THIS VOLUME DOES NOT CONTAIN A HARDWARE BOOTABLE SYSTEM ***
>        near the start
>
> I actually tried booting it once, and it then prints the string.

I suspect that second tape is not bootable then. I wonder where these 
tapes came from...? They do not seem to be the original distribution tape.

To make things clear, tapes and disks which are not bootable actually 
have a boot block, which only prints that message to the console, and 
then halts the cpu.

>> The BRU tape, which was separate in older systems, held only the BRUSYS
>> image, which you booted. And then you needed to switch tapes to the
>> distribution tape, to restore from.
>
> Seemingly that is still true with these files despite different names.
> Of course the pdf I have is for installing 4.3 and calls the boot tape
> BRUSYS.
> http://www.mirrorservice.org/sites/www.bitsavers.org/pdf/dec/pdp11/rsx11/RSX11Mplus_V4.x/2a/AA-H431H-TC_RSX-11M-PLUS_4.3_System_Generation_and_Installation_Guide_Jan90.pdf

Yes. V4.3 was distributed on two tapes. But the BRUSYS tape is really small.

It don't look like the tapes you have match a proper distribution. The 
"smaller" tape file do seem to have a BRUSYS image on it, but probably 
have some other stuff as well, based on the size of the thing.

The "large" tape seems to have a full system, but exactly what is in 
there, I have no idea.

> I wonder why the M tape is so large; applying "strings" to it shows lots
> of stuff including Macro-11 source files.
>
> Could it still be, like that manual suggests in section 2.2.1 on page
> 2-5, that it is indeed "BRUSYS Standalone Copy System and Layered
> Product Corrections"?

I don't think so. Sounds more like someone did a backup of a just 
installed/booted system on tape...

> Oh, still haven't had much time to look at Kermit :(

No worry. :-)

	Johnny