[Coco] Jumper settings needed

Tony tonym at compusource.net
Thu Oct 2 20:35:16 EDT 2008



----- Original Message -----
From: "LinuxRules" <Linux-Rules at austin.rr.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Thursday, October 02, 2008 6:51 PM
Subject: Re: [Coco] Jumper settings needed



> tonym wrote:

>>> -----Original Message-----

>> I don't how much of a difference it makes, and maybe I have my models

>> mixed up, and I can check when I get home, but I thought the M4853 was a

>> DS/QD 80T 96TPI 720kb FDD? I believe the M4851 is the 360kb DS/DD 40T

>> 48tpi

>>

>> The M4853 is what was used in the Tandy 2000's

>>

>> Wouldn't you have to set it up in the PC's BIOS as a 720kb FDD? It is the

>> exact same geometry as a

>> 3.5" 720KB floppy, and that is how I set it up in my PC for doing imaging

>>

>> Tony

> Would the geometry setup cause it to select the drive, but see it as Not

> Ready?

> I was thinking that incorrect geometry setup would simply make it

> unreadable.

> When I setup Drive-A incorrectly in BIOS, that is what happens.

> I.E. It is still found to be "Ready", but the media cannot be

> read..........

>

> Since last post, I found that Linux LiveCD also fails to mount the drive.

> Sure seems to be a hardware issue.....??....

>

> Aging brain cells don't work well, but I seem to remember that back in

> the "Old Days", floppy drives could be jumpered to provide "Ready"

> based on things like Head Loaded, Drive Selected, and/or Motor On,

> etc. I am suspicious that something like that is going on..........

>


I have a Revision L and Revision U M4853 in front of me.
I KNOW I used my Rev U in a PC, as it still has a diskette inside labelled
"MS-DOS."

On the jumper set near the FDC connector, DS1 is jumpered, and HM is
jumpered.
Going rear (nearest connector) to front (towards front of drive) using
binary:
01000010 1 being jumpered.

Mine also happens to have the term jumpers inserted, whic is about 1 inch
away from edge,
about 2 inches in from the FDC connector.

Rev U and Rev L are VASTLY different on other jumpers, ie, not the jumper
header where DS is
selected.

Tony




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