Radio Shack TRS-80 Trsdos & Disk Basic Reference Manual

Mini
Disk
Operation
Drive
Numbering
TRSDOS
requires
at least
one Mini Disk
drive, and can handle
up
to
four. Under TRSDOS,
these drives
are referred
to as drives
0,1,2
and 3
(where drive is closest to the
Expansion
Interface,
and drive 3 is
farthest away). See Figure
5. These
designations cannot
be changed
—
they are built
into
the ribbon
cable
connector.
When the Computer attempts
a bootstrap operation
(power-on or
reset),
it
will automatically
attempt
to load TRSDOS from
drive 0.
Therefore a
TRSDOS
diskette
must
be in drive
when
you
power on
or reset the Computer.
In
fact,
the TRSDOS
diskette
should
always
remain
in
drive
while
TRSDOS
is
in use,
except
in
special
cases.
Operation
Before
powering on
the disk system,
you need to
understand a
few
things
about
how the drives work.
The disk
drive
does not rotate
continuously
while it is "on".
It only
rotates
when
a Motor-On
signal is
sent
from
the Computer.
If more
than one
Mini
Disks are connected, the
Motor-On
signal will turn
them
all on and
off
simultaneously,
even if only one
of them
is to be
accessed
by
the
Computer.
This signal is sent
about a
second
before
the
Computer
accesses
the
disk, to allow
the drives to reach
operating
speed.
While the
Computer
is
accessing
one
of the
Mini
Disks, the red
light
(LED)
on the
front of
that Mini Disk
will remain
lit.
Caution:
Do
not open a drive
latch
to
insert or
remove
a diskette
while
the
drive motors
are running (i.e.,
while one
of the
LEDS
is lit).
How
a
Diskette
Works
A
diskette
is
simply a
circular plastic sheet, one
side
of which
is
coated
with
a highly
polished layer
of
ferromagnetic
material.
Similar
to
a
45
RPM
record, the
diskette
has
a
large spindle
hole to
accommodate
the drive hub,
and
a
small hole which
indexes
the
diskette
as it
rotates.
2-5

Radio Shack TRS-80 Specifications

General

Brand	Radio Shack
Model	TRS-80
Category	Desktop
Language	English