Date   : Sun, 14 Nov 2010 00:02:30 +0000
From   : jgh@... (J.G.Harston)
Subject: ROMs

Rick Murray wrote:
>>> Likewise, I *think* the DNFS is plain DFS and DNFS? I recall building up
>>> that EPROM but I don't know if I fitted it.
>> It's NFS, TUBE and DFS.
>
> Sorry, you got the wrong end of the stick here. I think *my* DNFS is
> DNFS in the lower half of the EPROM (default) and plain DFS in the upper
> half.

Ah, do you mean a 32K EPROM, so you can select between two different
16K images? I think I must have subconciously edited "DNFS" to "NFS"
when reading your post.

>> DNFS 2.00 is NFS 3.40, TUBE 1.00, DFS 1.00
>> DNFS 3.00 is NFS 3.60, TUBE 1.10, DFS 1.20
>> DNFS 3.01 is NFS 3.60, TUBE 1.10, DFS 1.21
>
> Do you know what is different here? I remember seeing a file listing
> NFS differences, but Tube/DFS?

DFS 1.00 enters executed code with A undefined, DFS 1.20 with A=1.
DFS 1.20 replaces a "Delete? (Y/N)" prompt with a call to the same
"Go? (Y/N)" prompt used by *BACKUP, *DESTROY, *WIPE.

TUBE 1.00 sends the transfer sync byte before a delay, TUBE 1.10 sends
it after the delay.
TUBE 1.10 disables IRQs when releasing the Tube.
TUBE 1.00 uses LDA &8000 to delay in language transfer, TUBE 1.10 uses
NOP:NOP:NOP.

DFS 1.21 fixes the Drive not ready problem that occurs when using
3.5" drives. Drive access loops until either OK or another error
occurs.

-- 
J.G.Harston - jgh@...