[CoCo] 720kb vs 1.4mb 3.5" disks

[John E. Malmberg]

KnudsenMJ at aol.com wrote:
> 
>> IT'S WINDOWS that throws the scare on you when 
>> you reboot, because it KNOWS it was not shut down properly, so it goes 
>> through this whole mess of hard drive scanning and file verifying.
> 
> Yes, and Linux insists on the same thing if not properly exited.  And that 
> includes using Ctrl-Slt-Delete too.  Only OS-9 is capable of booting right back 
> up after a power-down or reset.

It has to do with how the blocks are allocated on the disk and how the 
directories are populated.  When a file is written, the disk must be 
updated in more than one place at a time.  Usually the order is chosen 
so that if it is interrupted, the operating system will have clues to 
clean it up, and files will not get corrupted.  And either the operating 
system will have to clean it up, or space will be lost on the disk.

OpenVMS gives you the option to defer the clean up for a later time, but 
it is still better to do an orderly shutdown.  Except for software or 
hardware upgrades, most of my shutdowns are caused by the power going 
away as I do not have an UPS.

Most of the issues come from operating systems defering updates to the 
disk from having large file cache memory.

The COCO does not have lots of memory to buffer up I/O, so it is less 
likely to have a power interruption at a critical time that would leave 
orphaned space.

If there is not a utility to check the integrity of the OS-9 file 
system, then there should be.

> BTW, every Coco owner knows not to kill power without unclamping any floppies 
> in the drives, right?  I still remember the salesman demonstrating a PC Jr 
> telling me "This is a REAL computer, you don't have to worry about that anymore."

The only issue I ever heard about that is long term storage of the 
floppies with the heads clamped down was bad.

-John
wb8tyw at qsl.network
Persoanl Opinion Only