Share your knowledge on these two classic MPCs
By mike10 Fri Jan 12, 2007 11:50 am
Is there a faster way to format zip disks on OS 3.11(faster than 10 minutes)? I know OS 3.16 has a fast format and slow format, what's the difference besides speed, is one better to do than the other(is the fast format more succeptable to errors)?Thanks
By mpc3000le Fri Jan 12, 2007 12:02 pm
mike10 wrote:Is their a faster way to format zip disks on OS 3.11(faster than 10 minutes)? I know OS 3.16 has a fast format and slow format, what's the difference besides speed, is one better to do than the other(is the fast format more succeptable to errors)?Thanks


FAST format does not erase the disk.

FAST format creates the file system and partition structures only.

FAST format also makes a fresh FAT ( file allocation table ) and directory table; there by making old disk data in essence, inaccessible by the MPC3000.

FAST format on the MPC3000 is essentially the same as a QUICK FORMAT on other systems, M$ WINDOW$, MACO$, MPC2000XL and such.

A SLOW or long format ( available on the MPC60 and MPC3000 ) issues a SCSI "FORMAT UNIT" command to the connected storage device. All sectors get wiped and the bad block table in most cases gets updated.

The SLOW method is the "need to be certain I am writing to a blank disk" preference.

The FAST method will not get you in to trouble.

Note. Many SCSI card reader/writer's such as the PCD-15/25 combo's block the SLOW format command and return "COMMAND STATUS DONE" so in effect they can only be FAST formatted.

Rohan.

By mike10 Fri Jan 12, 2007 12:13 pm
Thanks Rohan for the info.

By mike10 Fri Jan 12, 2007 12:16 pm
Is fast format on the 3000 the same as formatting on the MPC 2000? cause my 2000 formats disk in a couple seconds. Thanks

By mpc3000le Fri Jan 12, 2007 12:37 pm
mike10 wrote:Is fast format on the 3000 the same as formatting on the MPC 2000? cause my 2000 formats disk in a couple seconds. Thanks


In essence, yes.

An MPC2000 creates MBR, PARTITIONS, FAT, EMPTY DIRECTORIES as necessary but doesn't erase the disk first.

I think AKAI removed the SLOW format option from 2000/2000XL ( and certain other machines ??? ) because of the way certain drives were behaving in response to a SCSI "FORMAT UNIT" command.

Rohan.

By mike10 Fri Jan 12, 2007 9:05 pm
So a slow format gives more writable disk space as compared to the fast format? since it erases the whole disk? Is that the advantage of slow format?Thanks.

By mpc3000le Sat Jan 13, 2007 4:05 am
mike10 wrote:So a slow format gives more writable disk space as compared to the fast format? .


No ... like I wrote above.

A SLOW format issues a SCSI "FORMAT UNIT" command.

How this is handled by various storage devices is anyones guess. ( different manufacturers handle this in their own way )

It is tradition for most older spinning platter based SCSI storage devices when issued with a "FORMAT UNIT" command to:

1: Attempt a write of ZERO's to each BLOCK/SECTOR.
2: Update the un-readable/un-writeable BLOCK/SECTORS by adding entries into a "BAD BLOCK or GROWN DEFECTS" table.

Not all disks handle the SCSI "FORMAT UNIT" command in a standard way though.

Again as an example. The popular PCD-25 responds with a "COMMAND DONE" message and doesn't actually do anything to the CF card that is inserted.

Some models of ZIP and JAZ drives in certain scenarios, crash, damage configuration "Z-TRACKS" and behave badly. ( in essence, voiding further use of the ZIP/JAZ cart ).

mike10 wrote:since it erases the whole disk? Is that the advantage of slow format?Thanks.


Assuming the connected storage device handles the SLOW "FORMAT UNIT" SCSI command correctly; then a SLOW format has the effect of presenting a clean slate to the next phase of formatting. IE: The PARTITION and FILESYSTEM creation phase.

I hope this makes sense.

Rohan.

By mike10 Sat Jan 13, 2007 10:36 am
Good enough, Thanks for the info.