There have been a couple of comments recently about
old floppies that have got me thinking. My
recollection in regard to floppy disks:
History: Pre-Floppy 3.5 will not be argued. The
following relates to 3.5 inch Auto Shutter "Micro
Floppy" aka "Microdisk" . As of 1998 is becoming a
questionable medium for anything other than cheap
transfer of small files, last ditch "temporary"
storage or use on older machines.
1. 400K: MF1-DD "Single Sided, Double Density,
Double Tracks" 1 square hole (lockable which will open
the hole. Closed is open! ?Stupid!). This is the only
disk 128K and 512K can read! Newer disks can format as
400K w/ preOS8. Not usable w/OS8 and up (data must be
transferred to other disk by use of earlier OS) Disk
can usually* be reformatted to be 800K. *the safety of
the second side is iffy unless reformatted w/OS7 which
skips bad spots. Will read as MFS unless OS7 trick
used (see below 800K). (history note: I paid $60 @
1985 dollars= ?100+$ current dollar price on 10 of
these).
2. 800K: MF2-DD 2S/2D "Double Sided", "DS" disks:1
square hole, identical to 400K, but increase in
technology (*Quality control?) allow newer (512Ke,
Plus, MacII, and some SE) to use both sides of disks.
Erasure allows choice of 400K on older machines. If
reformated to 400K using OS7 holding down Option key
allows HFS on 400K disk. Usable w/OS8 and up to ?. In
essence, you can store 800K on a double-sided, instead
of 400K on a single-sided disk despite both being made
the same way. Inspection methods and formatting
capability is the difference.
3. 1.4 MB: MF2HD or MFD-2HD "High Density" "HD" disks:
2 hole, major change allows X2 improvement. Save old
disks for recycle since new disks won't format to old
(unless fooled by taping over the second hole, which
is not a good idea. Don't trust it!).
4. OS7; HFS (Hierarchical Filing System) instead of
MFS (Macintosh Filing System) formating introduced ?
Essentially this means that HFS floppy won't work
pre-MacPlus and then only if OS7 or later installed.
Double sided disks were formatted as single-sided
disks under MFS. HFS was incorporated into the 128K
ROMs in the Mac 512Ke and up. ? But Mac 512Ke doesn't
have the 8MB req'd for OS7 ?
5. OS8 abandons older formatting capability. HFS+
becomes the new format.
Things that I am very uncertain about:
MFS to HFS change; it seems to me that Folders were
not really folders. You could put folders in other
folders. Your files were really separated. No more 1
huge list of files in the open dialog boxes.???
The Mac 128K/512K could not use HFS with this System.
Unless they had the "Hard Disk 20" file. ??
Early limitations were hardware, later limitations
after Plus (HFS) were software.
The floppies's use now seems to be non-network
transfer for:
A. Economical Transfer: if all that you have to do is
make quick person to person transfer, toss a floppy.
b.: This is the last battle line in order to recover
that which either has not been more efficiently stored
or
c. less reliable, less convenient storage of archived
files seldom used.
1. Mac 128 and 512 require 400K floppy
2. Essentially there is no difference between 400K and
800K except how they are formatted (one side vs.
both). Some early disks were bad enough that both
sides can't be formatted so they are 400K only.
3. 512KE to
Please correct me if I'm wrong. Regardless I hope that
this assists someone besides myself.
Don
__________________________________
Do you Yahoo!?
Yahoo! Mail - now with 250MB free storage. Learn more.
http://info.mail.yahoo.com/mail_250
--
Vintage Macs is sponsored by <http://lowendmac.com/> and...
Small Dog Electronics http://www.smalldog.com | Enter To Win A |
-- Canon PowerShot Digital Cameras start at $299 | Free iBook! |
Support Low End Mac <http://lowendmac.com/lists/support.html>
Vintage Macs list info: <http://lowendmac.com/lists/vintagemacs.shtml>
--> AOL users, remove "mailto:";
Send list messages to: <mailto:[email protected]>
To unsubscribe, email: <mailto:[EMAIL PROTECTED]>
For digest mode, email: <mailto:[EMAIL PROTECTED]>
Subscription questions: <mailto:[EMAIL PROTECTED]>
Archive: <http://www.mail-archive.com/vintage.macs%40mail.maclaunch.com/>
iPod Accessories for Less
at 1-800-iPOD.COM
Fast Delivery, Low Price, Good Deal
www.1800ipod.com
