[Info-vax] Backup TK50 tapes

[Johnny Billquist]

On 2013-02-27 22:40, Bob Koehler wrote:
> In article <kglb7k$thf$1 at Iltempo.Update.UU.SE>, Johnny Billquist <bqt at softjar.se> writes:
>>
>> Correct, I think.
>> I know that the RL02 on the 86x0 machines holds a full RT-11 system, as
>> that is what the FE is running there.
>> Very simple file system, and the VAX was booted by that thing.
>
>     The LSI-11 on the 11/780 used what looked like a subset of RT-11.
>     A lot like looking at RSX-11F on the PDP-11/40 front end to our
>     PDP-10.  Familiar, but not RSX-11M.  Unlike the LSI, after boot,
>     the 11/40 had more to do in normal operations than just exchange
>     bytes with the console terminal.

To be honest, RSX-20 (the FE of the -10) is actually pretty much an 
unmapped 11M-system. However, few people ever played with unmapped RSX, 
so it might definitely look strange if you are not used to it.
Straight off my head, the biggest differences between RSX-11M and 
RSX-20F was that you had the DTE interface on the 11, and you had a 
modified RH11, which would play on 18-bit formatted RP06., and then some 
modifications to some drivers to live in this environment.
There might have been some change in the kernel as well, but I can't 
remember any offhand. I did play around on RSX-20F at one point, many 
years ago, and it was very much the same as -11M in all aspects I can 
remember. The unmapped part did give me a fit, though. :-)

I never played enough on the FE of an 11/780 to really tell what it was, 
but I've heard it was a subset of RT-11.
I know that the FE of the 86x0 machines is a proper RT-11, which you can 
even get into, and then play as with any RT-11 system. However, it 
normally runs a program (EDSAA?), which makes it just act as the FE to 
the VAX.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol