Date   : Mon, 03 Mar 2008 20:08:57 -0000
From   : dl.harper@... (David Harper)
Subject: TUBE code in the Master

Pete Turnbull wrote:

> I was sure it's in the 1770DFS part.  On a Model B, it's in the DNFS ROM
> or 1770DFS, and in some mid-life versions of the NFS ROM.  On a Master,
> it's only in the 1770DFS, AFAIK.

No, it isn't. It's with "Terminal" in ROM bank &F (see my earlier message).

There is no particular reason why it should be associated with a filing 
system ROM. They just had to find somewhere to put it, and there wasn't room 
in the original Model A/B MOS ROM. (It wouldn't work with the earliest OS 
ROMs anyway.)

It seems to have been assumed that no-one would want to use the Tube without 
a disk or network filing system installed as well, so the Tube host code was 
included with these filing system ROMs. (It never was included with ADFS, as 
far as I recall - again lack of space. Even if you want to use ADFS as your 
only filing system on a Model B, you still have to have one of the other FS 
ROMs in the machine if you want to use the Tube.)

There is other stuff in the same ROM bank as DFS (bank 9), in particular the 
Sideways RAM utilities (SRLOAD, etc.), but not the Tube code.

If you *UNPLUG F, then you will find you cannot use the Tube. On the other 
hand, *UNPLUG 9 will not affect the Tube, though it will disable DFS and the 
Sideways RAM commands.

David Harper