RE: Trouble Floppy Booting an MVME167
I performed detailed test booting with changes to four parameters.
First, here are all the parameters.
Floppy Types and Formats
IOT Parameter DSDD5 PCXT8 PCXT9 PCXT9_3 PCAT PS2 SHD
0-128 1-256 2-512
3-1024 4-2048 5-4096 1 2 2 2 2 2 2
0-128 1-256 2-512
3-1024 4-2048 5-4096 1 1 1 1 1 1 1
Sectors/Track 10 8 9 9 F 12 24
Number of Heads 2 2 2 2 2 2 2
Cylinders 50 28 28 50 50 50 50
Precomp. Cylinder 50 28 28 50 50 50 50
Current Cylinder 50 28 28 50 50 50 50
Step Rate Code 0 0 0 0 0 0 0
DATA Density D D D D D D D
TRACK Density D D D D D D D
Track Zero Density S E E E E E E
Slow/Fast Data Rate S S S S F F F
The parameters were initially set according to the DSDD5 setting.
I am quite sure that some old Mtool utilities were used successfully at this setting.
Perhaps these tools ignored the above parameters.
The initial setting allowed a successful load of the first stage kernel.
However, during the load of the second stage kernel, system call reads didn't really read.
Four changes were required to change to the PS2 setting:
Sector Size 256 to 512
Sectors/Track 10 to 12
Track Zero Density Single to Equal
Data Rate Slow to Fast
All four changes were apparently required, since changing any three always failed.
If booting was attempted with the four changes except either the sector size,
the track zero density, or the data rate, then the booting failed in a manner
like the initial setting. That is, there was a successful load of the first stage kernel.
Oddly, inspection of the parameters after a boot attempt with no change to the data rate,
but with the other three changes, revealed that the data rate parameter was somehow changed from
S to F and the sectors per track parameter was somehow changed from 12 to 0F.
If booting was attempted with the four changes except either the sectors per track,
then the booting failed to load the first stage kernel.
That is, this setting was worse than the initial setting.
From: Christian T. Steigies [mailto:firstname.lastname@example.org]
Sent: Tuesday, July 03, 2001 2:12 PM
To: Churchill, David
Cc: 'Nick Holgate'; Debian-68k@Lists. Debian. Org (E-mail)
Subject: Re: Trouble Floppy Booting an MVME167
On Tue, Jul 03, 2001 at 01:45:02PM -0600, Churchill, David wrote:
> Thank you for all the great information.
> I determined that the floppy disks were correct.
> Everything up to diskread system call appeared correct.
> The disk drive activity light would come on for about a second only.
> This was not long enough to read the 48 requested blocks.
> I checked the floppy disk parameters using IOT, and found them NOT to be correct.
> After changing these parameters (e.g., sector size), I booted the Woody image.
> It is interesting that the first stage kernel loading appeared OK with the incorrect parameters.
What did you have to change? Is there anything we can fix in the
boot-floppies so that it will work out of the box next time?
Not that I know anything about vme or floppies, but maybe we can improve it.
> Have a great 4th.
I hope so, its my first :-)