Tektronix 067-0892-00, Инструкция по эксплуатации, Страница: 17 / 110

TAPE
LOAD
(SHIFT
2)
Key
The
TAPE
LOAD
key
is
used
to
load
a
file from
cassette
tape
into
the
MicroLab
|
memory.
When
(SHIFT) TAPE
LOAD
is
pressed, the word
“FILE” is shown
on
the
display.
This
is
your
cue
to
enter
a
two-digit
file name.
After
the
file
name
is
entered, the
monitor
will
display
“SEArCH”,
andscan
the
tape
for
the
file
specified.
If
the
file
is
not found,
press
SHIFT
to escape.
If
the
file
is
found
but
the
file
header cannot
be
verified,
the
display
will
show
“ERROR
C8”.
If
the
file
is
found
and
the
header
is
verified,
the
monitor
will
verify
the
contents of
each
block
in
the
file
by
testing the checksum.
The
checksum
value
is
verified
twice.
If an error
occurs
in
the first checksum,
the
display
will
show
an “ERROR
C9”.
If
the
error
occurs in
the second
checksum,
the
display
shows
“ERROR
CA”.
If
there
are no
checksum
errors,
the
display
will
show the
beginning
address
of
the
file
just
loaded.
TAPE
SAVE
(SHIFT
3) Key
The
TAPE
SAVE key
allows
files
stored
in
MicroLab!
memory to be
saved
on
cassette tape. When
(SHIFT) TAPE
SAVE
is
pressed,
the
display
shows
“FILE”.
After you enter
a
two-digit file name,
the
display
will
show
“SA”
(starting
address). Enter
a
four-digit beginning
address. When the
Operator
Familiarization—MicroLab
|
Instruction
last
address
digit
is
entered, the
display will
clear,
then
show
“EA” (ending address),
and wait
for an ending
address. After you
enter
an ending address, the
display
will
show "GA".
The
“GA”
display
is
the starting
address
of
the
program you want
to
save.
For example,
if
your executable
code
exists
from
137B
to
2000,and
a
data
table
exists
from
1000
to 137A, you'll
want
to
enter
137B
as
the
"GA"
value.
Later,
when
you
load
the
program to run it,
the
"GA”
address
is
loaded
into
the
CAP to tell you
where
the
beginning
of
exacutable
code
is.
Once
the
"GA”
value
is
entered, the
monitor
will
pause
for
about
three seconds, and then begin dumping
the contents
of
the
specified
address range onto
tape.
As
each
byte
is
written,
the
address and
data are shown
on
the
display.
When
the
last
address
is
written,
the
display
will
show the
ending
address and
the
data
at
that
location.
F1—F8
(SHIFT 8—F)
These
keys
are
programmable, and
we'll discuss
how to
program
them, and
some
oftheir
possible
uses,
later
in
this
section.
PROCEDURES
Introduction
The next
few pages
will
help you make
use of
the
capabilities
of
the MicroLab
|.
In
this
part
of
the
manual,
we'll talk about
the
following subjects:
@
using
the cassette
tape
port;
@
programming
the
user-definable
keys;
@
using
the
MicroLab
|
with an optional terminal;
©
programming
the
MicroLab
|
display
and
keypad;
@
relocating
a
1K
block of
RAM;
and
©
using
the
self-test features
of
the
MicroLab
|.
Cassette
Tape
File Storage
and
Retrieval
MicroLab
|
is
able
to
store
and
retrieve
files
from
a
relatively
inexpensive
cassette tape recorder. (The
recorder
is
an
option provided
by
the
you.)
The recording
format
is
called
“Kansas
City
Standard”.
This standard
is
a
fairly
forgiving
@
recording
method
in
terms
of
recorder and
tape
quality.
Data
is
recorded asynchronously at
300
baud.
There are
eight data
bits
and one
stop
bit
used, with even
parity
detection.
Each
file
has
a
two-digit hexadecimal
name
assigned
to
it.
This
file
name
is
entered
when
the
file
is
first
stored.
Files
are retrieved
simply
by
specifying
the
file
name.
Tape
Recorder
Quality
A
word
here
about
the
kind
of tape
recorder you'll use with
the
MicroLab
|.
Although
the "Kansas
City
Standard”
is a
slow, simple
standard
that
will
work with
almost
any
quality audio
cassette tape recorder, good judgement
should be used. A low-priced tape
recorder using
the
cheapest tape
possible
may
work,
but
results
will
be much
more
satisfactory
if
you
use
high quality
tape
in a
medium
priced machine.
If
the recorder
you
use has
an automatic
volume
setting
feature,
it
should
be disabled
in some
way
so
that
you
can
setthe
recording
level.
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