There is nothing in a standard disk drive MFM interface that signals the
drive size. This is almost always a jumper setting and almost always on the
controller; one set of jumpers for each drive controlled. If the controller
also has some BIOS on it, it could be a BIOS jumper setting.
Tom
-----Original Message-----
From: Robert Jarratt [mailto:robert.jarratt at
ntlworld.com]
Sent: Saturday, January 04, 2014 3:36 AM
To: General Discussion: On-Topic and Off-Topic Posts; DEC discussion list.
Subject: MFM Control Signals and RD disk size
As I don't have a logic analyser to help me with my analysis of the MFM
interface, can anyone tell me how the MicroVAX 2000 determines disk size?
I
know it is related to the number of heads, but what does the drive do when
the host asks for a head that does not exist? How does it report this
back?
The only thing I can think of is the Ready signal, could that be it?
Regards
Rob