Computer Interfacing

Computer interfacing

Basic functions

of a

floppy disk controller

These

are as

follows:

(a) select drive:

one

controller

may

look after

a

maxi-

mum

of

four drives, with

the

ability

to

select

any one on

receipt

of the

appropriate command,

(b) seek track:

a

sequence

of

step pulses moves

the

read/write head

to the

required track,

in a

particular

direction.

If

moving outwards,

the

track

0

signal

is

used

to terminate

the

movement when this track

is

reached,

(c) read/write:

the

controller loads

the

head onto

the

disk surface, allows

a

settling time before

the

transfer

commences

and

generates

a

signal

to

select either

the

read

or

write mode,

(d) data ...