In article ,
Dave Hinz wrote:
On 17 Apr 2005 22:03:18 -0400, DoN. Nichols wrote:
In article ,
Dave Hinz wrote:
On 15 Apr 2005 19:12:48 -0400, DoN. Nichols wrote:

Just out of curiosity, I tried surgically removing the floppies
from their jackets and installing them in the jackets of other, already
dead, floppies. Amazingly enough, I could still read everything on the
floppies -- but I am very glad that I did not have to use those to
recover data.

Well, to be fair, at 156K (?) per 8" floppy, you can _see_ the individual
bits at that size...

Are you sure you aren't thinking of 5.25" floppies? Even single
sided single density floppies were 250K per floppy (26 sectors, 128
bytes per sector, and by that time I was running double sided double
density (1 MB per floppy).

I don't remember 8" disks being 250K, but maybe the later ones were.

I've finally got it figured out. The earliest thing that had
8" floppies which I dealt with was an IBM drive (very slow step rate,
with Geneva gears driving the leadscrew). That one was 77 tracks, 26
sectors per track, 128 bytes per sector -- but it was being used for
storing punched card images, so there were only 80 bytes stored in that
128 byte sector -- taking the *effective* capacity down to your 156k.

At least I got in after "hard sectoring", but they still did need the
timing hole.

Yep -- I've dealt with some hard sectored ones as well -- and
they held more, because without the soft sectoring overhead, they got 32
128 byte sectors per track.

Even the 3.5" floppies use a timing hole -- it is just on the
hub in the drive, which is keyed to the floppy.

But most of my use of the 8" floppies was either at 500K (Double
Sided, Single Density) or at 1MB (DSDD).

Media migrations are a pain. But if you don't do 'em, you've got 10 years,
20 tops, before they're very very difficult indeed. Paper & stone tablets
aren't all that bad, in that context.

Some of my migrations involved re-writing the programs, such as
from the original random disk BASIC (SSB's DOS 68) to Pascal (6809 OS9),

I _loved_ OS9 on the 6809. Got my Unix experience started early, more
or less.

So did I. It gave me enough experience so when a friend at the
next building at work got a pair of unix boxen to administer (for
e-mail), I was able to show him some tricks, and that resulted in him
talking his boss into giving me a free account, so I could do things
like port net based utilities to the (rather weird) BBN C70 (10-bit
bytes, 20-bit words, 40-bit longs. :-)

The common compress program (LZW algorithm) would work fine on
text files, but blow up spectacularly on binaries. However, there was a
compress program from the OS-9 UGL which had tuning parameters for
10-bit bytes, and that one worked beautifully. It saved his rear a few
times while doing backups.

I'm trying to remember what OS-9 used for a pipe symbol, instead
of the '|' now. :-)

and from Pascal to C to my first unix box. Once in unix, it went from
8" floppies to 9-track tapes, and from there to a Sun platform, and to
the QIC-150 tapes.

Want a drive? Nice Sun shoe-box enclosure, with those damn hidden latches
on the side?

Oh -- you mean the sandwichbox ones -- half the height of the
LX and several others of the small square box computers. I've already
got several drives, including one QIC-150 in the Solbourne box (a
semi-clone of the SS2 boxen, but faster and neater). From here, I can
see four of the sandwichbox enclosures -- one disk, and three CD-ROMs,
one of the "lunchbox" enclosures with a 1GB 5.25" full height in it) and
two of the later unipack enclosures -- one SCA disk, and one Exabyte
8505XL tape, and below those two, a 6-drive MultiPack (one of three of
those that I have).

I've still got the source and the database -- last properly run
on a 68020 based Sun3, and it would take some work to re-tune it for the
current Ultra-SPARC machines.

Our paths keep crossing, Don.

:-)

Enjoy,
DoN.
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