360 Systems AM-16/B User manual

MODEL AM-16/B
AUDIO CROSSPOINT
SWITCHER
OWNER'S MANUAL
REVISION 2.01
360 SYSTEMS
5321 Sterling Center Dr.
Westlake Village, CA 91361
TEL [phone] FAX [phone]

iAM/16-B Audio
PRODUCT IMPROVEMENTS AND
360 Systems reserves the right to make changes or improvements to
its products, without incurring any obligation to incorporate such changes or
improvements in units previously sold or shipped.
TRADEMARKS AND PATENTS
360 Systems and AM/16 are trademarks of 360 Systems. Software
contained in this product is copyright by 360 Systems. Designs incorporated
in this product may be the subject of current or pending U.S. and foreign
patents.
LIMITED WARRANTY
The 360 Systems Model AM/16 Audio Switcher is warranted against
defects in material and workmanship for a period of one year from date of
original purchase. This warranty includes parts and labor.
This warranty excludes units that have been modified, repaired by
unauthorized personnel, or damaged by abuse, improper operation, dirt, or
static electricity.
360 Systems assumes no liability whatsoever for real or consequen-
tial damages, loss of profits, inconvenience or any other losses due to non-
operation of the product.
360 Systems' sole liability under this limited warranty shall be the
repair or replacement of defective product or components. Products being
returned under warranty shall be sent to 360 Systems or one of its foreign
service centers, freight prepaid in the original or equivalent packaging.
SHIPPING ADDRESS
Freight and mail may be sent to 360 Systems at the following address:
360 Systems
5321 Sterling Center Dr.
Westlake Village, CA 91361
The primary telephone number is [phone]. The switchboard is
open from 8:00 AM to 5:00 PM, California time. Faxes may be sent to
[phone], 24 hours. Send email regarding operation and
technical questions to [email protected].
Visit our website at 360systems.com.


AM/16-B Audio Switcher ii
TABLE OF CONTENTS
THE AM-16 SERIES SYSTEM DESCRIPTION
0.10 The AM-16/B Master Crosspoint Switcher 2
0.20 The AM-16/E Expander Module 2
0.30 Remote Control Capabilities 3
0.31 EIA-422/485 Remote Control 3
0.32 MIDI Remote Control 3
0.33 Using MIDI & EIA-485/422 At The Same Time 4
INSTALLING THE AM-16/B AUDIO SWITCHER
1.10 AC Power 5
1.11 Power Switch 5
1.12 Fuse 5
1.20 Audio Connector Wiring 5
1.21 Audio Input Connections 6
1.22 Audio Output Connections 6
1.23 Balanced vs: Single Ended Gain Structure 6
1.24 Rear Panel Gain Adjustments 6
1.25 Front Panel Audio Jacks 7
1.30 Remote Control Ports
1.30 EIA-422/485 Port 7
1.31 MIDI Input Port 7
1.32 MIDI Output Port 7
1.33 Interface Port to AM-16/E Expander Modules 8
1.40 Configuring Internal Jumper Options 8
1.41 Mono/Stereo Select 8
1.42 EIA-422/485 or MIDI Select 8
1.43 EIA-422/485 Termination Jumper 9
USING THE AM-16/B AUDIO SWITCHER
2.00 About The Operating Modes 10
2.01 The Edit Buffer 10
2.10 Program Select Mode 10
2.11 Selecting Stored Programs 10
2.12 Remote Program Selection 10
2.20 Program Edit Mode 11
2.21 Constructing Audio Paths 11
2.22 Multiple Input Assignments 12
2.23 Storing Edited Paths As A Program Number 13
2.24 The Store-Pending Timer 13

iii AM/16-B Audio Switcher
2.25 Memory Protect 13
2.26 Copying Programs 14
2.27 Block Copy/Making Multiple Copies 14
2.28 Using Bypass As An Edit/Compare Function 14
2.30 Program Send Mode 15
2.31 Creating MIDI Program Maps 15
2.32 Storing MIDI Program Maps 16
2.33 Editing MIDI Program Maps 16
2.40 Program Send Enable Mode 17
2.41 Selecting EIA-485 Transmission 17
2.50 Program Chain Mode 17
2.51 Selecting A Stored Chain 18
2.52 Programming a Chain 18
2.53 Storing A Chain 19
2.54 Editing A Chain 19
2.55 Special Chain Characters 19
2.56 Chain Footswitch Jack 19
2.57 Selecting Chain Steps Through MIDI 20
2.60 Receive Channel Mode 20
2.61 Programming the Receive Channel 20
2.70 Mono/Stereo Modes
2.70 The Monaural Mode 21
2.71 The Stereo Modes 21
2.80 The Bypass Mode
2.81 Selecting Bypass 21
2.82 Programming Bypass 22
2.90 Transferring RAM Data Via MIDI System Exclusive 22
2.91 Sysex Transfers To The AM-16/B 22
2.92 Sysex Transfers From The AM-16/B 22
APPENDIX
Appendix A: Initialization 23
Appendix B: Software Revision Number 23
Appendix C: Technical Specifications 24
Appendix D: Connector Components & Wiring 25
Appendix E: Remote Control: AM-16/B Midi Specification 29
Appendix F: Remote Control: AM-16/B Communication Spec. 30
Appendix G: Remote Control: AM-16/B Data Structures 37
Appendix H: Operation at 38.4k Baud 40

AM/16-B Audio Switcher 1
INTRODUCTION
OBTAINING THE AM-16/B MAINTENANCE MANUAL
Fill out the warranty card in the front of this manual and return it to 360
Systems as soon as possible. On receiving it, we will send you the maintenance
manual, which includes schematics and repair tips. Registration of your unit
also entitles you to free repairs during the first year, and will let us contact you in
the event new software or support materials become available.
CAUTION
VERIFY THAT THE VOLTAGE MARKING ON THE REAR PANEL IS
SUITABLE FOR THE MAINS POWER AVAILABLE IN YOUR AREA OR
COUNTRY.
DO NOT REMOVE OR DEFEAT THE GROUNDING PIN ON THE AC
POWER CORD. A SERIOUS SHOCK HAZARD CAN RESULT FROM
FAILING TO MAKE CONNECTION TO A PROPERLY GROUNDED
ELECTRICAL OUTLET.
DO NOT USE THIS PRODUCT OUT OF DOORS, IN RAIN, OR IN DAMP
OR WET ENVIRONMENTS.
360 Systems is in its 20th year of designing unique and useful products for
the audio industry. We rely on feedback from our customers to help us continue
the development of innovative and affordable products. Please feel free to
address any comments regarding 360 Systems products to us at:
360 SYSTEMS
Director Of Marketing
5321 Sterling Center Dr.
Westlake Village, CA 91361

2AM/16-B Audio Switcher
AM-16 SERIES SYSTEM
The AM-16 Audio Crosspoint Switcher contains a large feature set of useful
tools designed to assist the broadcaster, sound contractor and recording
engineer. This manual explores its technical capabilities, and describes a
number of ways it can be used to solve specific problems. Because so many
features are provided, the reader will find it useful to refer to the Table of
Contents when searching for a particular topic.
The AM-16 Series is an expandable audio switching matrix built of two
primary components-- the AM-16/B Master Crosspoint Switcher, and an optional
companion piece, the AM-16/E Expander Module. These two basic blocks can
be associated with each other in a variety of ways. An exceptionally versatile
remote control capability makes it easy to control the switchers, using off-the-
shelf controllers, or sophisticated custom interfaces.
0.10 THE AM-16/B MASTER CROSSPOINT SWITCHER
All the components required for a basic 16 x 16 system are contained in the
AM-16/B master unit. It provides electronically balanced inputs and outputs, and
incorpor-ates a new generation of CMOS crosspoint switches having
exceptionally good audio performance. Audio switching is managed by a micro-
computer system providing instantaneous response, non-volatile storage of
routing programs, and intelligent interfacing with remote controllers. Large
numeric displays provide an easy view of program status, while backlit legends
assist the user in operating the front panel controls.
The master unit may be operated as a 16 x 16 monaural switcher, or as an 8
x 8 stereo unit. In stereo, audio channels are managed as pairs, and are
indicated as 1 through 8 on the displays. Larger systems may be constructed by
using several master units in parallel, to provide an expanded number of inputs
or outputs.
0.20 THE AM-16/E EXPANDER MODULE
Basic systems may be enlarged with the addition of one or more Expander
modules. They contain audio circuits identical to the master unit, and use
commands from the master's micro-computer to control their audio. A single
expander module, together with one master, will make a 16 x 16 stereo switcher,
while one master and three expanders will provide a 16 x 16 matrix, four
channels deep, as used in the new "D2" format VTRs.
Expander Modules connect to the master unit by a single flat cable and are
self-powered. They require no controls, and are designed for use only with the
AM-16/B master. A maximum of three expanders may be connected to a single
master.
0.30 REMOTE CONTROL CAPABILITIES

AM/16-B Audio Switcher 3
The master unit may be controlled locally from its front panel, or remotely
through MIDI or an EIA-422/485 port. Apart from the basic tasks that may be
directly executed through single commands, many "software hooks" have been
incorporated so that specialized functions may be written into custom software.
Basic remote commands include:
Program recall
Increment chain step
Decrement chain step
Bulk data upload
Bulk data download
Bypass On/Off
Software hooks are described in detail in Appendix F. The AM-16/B can
receive commands through MIDI or the EIA-422/485 port, but not both. A user-
installed jumper selects a port, as described in section 1.42.
0.31 EIA-422/485 REMOTE CONTROL
A nine-pin "D" connector is provided for communication by the EIA-422 or
EIA-485 electrical standards. Each has the advantage of operation to at least
1,000 feet (305 meters).
Section 2.41 describes selection of MIDI or EIA-485 communication modes
from the front panel.
EIA-422 is a receive-only port on the AM-16/B. It is possible to connect a
number of switchers to a single 422 cable in a multi-drop configuration, with
each listening on its own channel. It may be convenient to think of 422 as a uni-
directional link.
EIA-485 is electrically similar to 422, but it is bi-directional. Many
transmitters and receivers may be attached to a single twisted pair cable in a
simple multi-drop installation. In use, each box "tests" the cable to see if it is
busy before using it.
An important feature of the AM-16 Series is that if any of the devices
connected to a 485 line is turned off, it releases the line. This greatly enhances
the reliability of larger systems. Similarly, any device can be unplugged from the
485 line without interfering with the integrity of the remote control line.
0.32 MIDI REMOTE CONTROL
MIDI uses two connectors-- one for transmit and one for receive. It is ideal
for short cable runs (less than 50 feet); and because of its popularity in the
music industry, several inexpensive remote control units are available. A wide
range of IBM, Apple and Atari software is also available for remote control.
MIDI cables may not be "Y" connected, or used in multi-drop configurations.
They may be easily split by connecting them to what is known as a "Thru-Box",

4AM/16-B Audio Switcher
which actively drives each of its outputs. Details regarding the Midi specification
can be found in Appendix E.
0.33 USING MIDI AND EIA-422/485 AT THE SAME TIME
When the 422/485 port is used, the AM-16/B is not listening on the MIDI
input port. However, MIDI program maps (see section 2.30) and bulk data
transfers may still be transmitted through the MIDI output port. This way,
outboard audio gear accepting MIDI program commands can be controlled by
the switcher, which in turn is controlled by a 422/485 transmitter.

AM/16-B Audio Switcher 5
Chapter
INSTALLING THE AM-16/B
1.10 A.C.
Connect the power cable to a grounded outlet. Versions of this product are
produced for use with different voltages. Be certain the voltage marking on the
rear panel is suitable for the area in which it is to be used.
1.11 POWER SWITCH
The A.C. power switch is located on the left side of the front panel. It shows
a blue area when in the "on" position. One or more of the displays will also
illuminate when power is applied.
1.12 FUSE
The A.C. fuse is located on the rear panel of the AM-16/B. Replace it only
with the same type and rating. For 120 volts, use a 1-amp, 3AG slow-blow. For
230 volts, use 1/2-amp, 3 AG slow-blow.
1.20 AUDIO CONNECTOR WIRING
Fifty-six pin ELCO Type 8016 connectors are used for audio inputs and
outputs. Mating plugs are provided, with loose terminals. These bifurcated
terminals are gold plated, and provide excellent reliability and resistance to
oxidation. They may be installed in the plug shell while the AM-16/B is
connected and operating, and may be easily removed with an appropriate ELCO
tool. See Appendix D.
The pinout for the ELCO connectors appears in Appendix D. It is also silk-
screened on the rear panel of the AM-16/B. For reference, pin locations are also
provided. Both inputs and outputs use an identical pinout, with the exception of
channel 11, which has the + and - connections reversed on the output
connector. Note that this discrepancy is not reflected in the rear panel silk
screen.

6AM/16-B Audio Switcher
The mating plugs provided with the AM-16/B include cable strain reliefs. A
variety of other connector parts are available from ELCO distributors. See
Appendix D for a listing of optional part numbers and sources.
1.21 AUDIO INPUT CONNECTIONS
Audio inputs are electronically balanced with respect to ground. Each input
is identical, and has an impedance of 40.2 k ohms. For balanced applications,
connect to the + and - terminals, and use the ground terminal for the shield.
Single-ended (unbalanced) connections may be made between ground and
either the + or - terminal. The user therefore has the option of making the overall
signal path inverting if desired. It is a good idea to connect the unused input to
the ground terminal for the same channel.
NOTE: When wiring an input, use only the ground terminal for that particular
channel. Do not share grounds with other channels.
1.22 AUDIO OUTPUT CONNECTIONS
Audio outputs are electronically balanced with respect to ground and have a
source impedance of 100 ohms. For balanced applications, connect to the + and
- terminals and use the ground only for the shield.
Single-ended (unbalanced) connections may be made to either the + or -
terminal, and ground. The user has the option of making the polarity of a signal
path inverting by selecting the minus (-) output. Do not ground the unused
output.
1.23 BALANCED VS SINGLE-ENDED GAIN STRUCTURE
The gain of the AM-16/B depends on the type of connection made to it. A
gain of unity might be obtained with a balanced input connected to the + and -
input terminals, and a balanced output measured between the + and - output
terminals. The same input voltage applied between ground and a single input
terminal will produce a differential output voltage 6 dB less. Similarly, a given
input voltage applied in a balanced connection will produce an output voltage
6 dB less, if measured between ground and either output terminal. If both input
and output are unbalanced, the total reduction will be 12 dB.
1.24 REAR PANEL INPUT GAIN ADJUSTMENTS
Level trims on the rear panel adjust the input gain of each channel; they do
not alter the output amplifier gain. The trims may be used to produce
standardized output levels from different level audio sources. An adjustment
range of -6 dB to +4 dB is available.

AM/16-B Audio Switcher 7
1.25 FRONT PANEL AUDIO JACKS
In addition to the rear panel connectors, input and output channels 8 and 16
(stereo pair #8 in the stereo mode) are available on the front panel as single-
ended 1/4" jacks. These convenience jacks are for studio situations where
outboard equipment or test signals are to be inserted. Plugging a jack into the
front panel input connectors will disconnect signals presented to channels 8 or
16 on the rear panel inputs.
An additional 12 dB of gain is provided on the front panel input jacks. This is
to facilitate connection of consumer gear or -10 dB semi-pro equipment.
The output jacks are at the same level as the rear panel connector, and do
not interrupt the rear panel output.
1.30 THE EIA-422/485 PORT
A 9-pin female "D" connector located on the rear panel serves as an EIA-
422 receive-only port, or as an EIA-485 bi-directional port. See section 1.42,
2.41 and Appendix F for additional data on using the ports. The following
connector pinout is used: Pin 1 Ground
Pin 2
Pin 3 Signal (+)
Pin 4
Pin 5
Pin 6
Pin 7
Pin 8 Signal (-)
Pin 9
1.31 MIDI INPUT PORT
Use a standard 5-pin MIDI cable to connect the MIDI IN of the AM-16/B to
the MIDI OUTPUT of a MIDI equipped computer or MIDI program number
transmitter. Any device capable of sending program numbers via MIDI may be
used to control the AM-16/B, i.e. keyboards, foot controllers, etc.
1.32 MIDI OUTPUT PORT
A cable may be connected from the MIDI OUT connector of the AM-16/B to
send program change information to other MIDI-based audio equipment. It may
be desirable to use a "Thru-Box" or a Midi Patcher to split the MIDI output into
the separate parallel paths for all the outboard equipment. Alternately, the MIDI
cable may be "daisy-chained" through outboard gear equipped with “Thru” jacks.

8AM/16-B Audio Switcher
The MIDI IN and MIDI OUT connectors may also be used to upload and
download the contents of the AM-16/B's memory to a computer or to another
AM-16/B. See section 2.90 for further information on these features.
1.33 INTERFACE PORT TO AM-16/E EXPANDER MODULES
A 15-pin female "D" connector on the rear panel provides all signals needed
to control additional AM-16/E Expander Modules. A maximum of three
expanders may be added, and a special interface cable must be ordered to
connect the expanders to the AM-16/B. When ordering this cable, specify
whether one, two or three AM-16/E expanders are to be connected.
1.40 CONFIGURING INTERNAL JUMPER OPTIONS
CAUTION: Before changing the jumpers, turn the power off
and unplug the unit. Ground yourself to the chassis to
discharge static electricity on your fingers before touching
anything inside the box.
Several push-on jumpers inside the AM-16/B select user options. The
jumpers may be removed with the fingers and replaced in the desired position by
pressing them onto a pair of square pins until seated.
1.41 MONAURAL/STEREO SELECT
Jumper JP1 (located on the front panel printed circuit card) selects whether
the AM-16/B operates as a 16 x 16 monaural switcher, or whether programs are
paired together for stereo, as an 8 x 8 unit. Place the jumper between the center
pin and the appropriate outer pin. Each is clearly labeled STEREO or
MONAURAL. Stereo pairs are arranged as:
1 and 9 5 and 13
2 and 10 6 and 14
3 and 11 7 and 15
4 and 12 8 and 16
This arrangement is also the way channels are paired for stereo on the front
panel scribble strip.
1.42 EIA-422/485 OR MIDI SELECT
The AM-16/B can receive remote control commands through either the 9-pin
EIA-422/485 connector or through the MIDI IN port. It is necessary to select one
or the other with jumper JMP1, located on the right rear corner of the large circuit
card. This is set at the factory for EIA-422/485 for use with the AM-16R Remote.

AM/16-B Audio Switcher 9
Place the jumper between the center pin and the appropriate outer pin. One
is marked "MIDI", and the other is marked "485".
Be certain to select the "normal" (MIDI) or "485" communications mode as
described in section 2.41.
1.43 EIA-422/485 TERMINATION JUMPER
When using long lines to send data via EIA-485 to the switcher, improved
wave shape can be achieved by resistively terminating the line. A 150-ohm
termination can be placed across the line by installing JMP2, located at the right
rear corner of the large circuit card. As shipped, the jumper is installed on only
one of the pins; remove it, and place it across both pins.
AM-16B REAR PANEL

10 AM/16-B Audio Switcher
Chapter Two
USING THE AM-16/B AUDIO SWITCHER
2.00 ABOUT THE OPERATING MODES
This overview begins with the most commonly used features, and then
reviews the more seldom-used aspects. You will find it helpful to put the
AM-16/B in front of you while reading about its operation, or refer to Figure 1.
The AM-16/B has six operating modes, selected by the blue MODE SELECT
button. One of these may be selected at a time, and is indicated by an LED. A
helpful feature of the device is that other legends and displays appear only as
necessary to clarify the task at hand.
2.01 THE EDIT BUFFER
As a convenience to the user, the AM-16/B allows all editing to be done in a
temporary memory space called the Edit Buffer. Information placed in the Edit
Buffer can be altered, deleted and reviewed without fear of damaging "real
information" in the main memory. When a final decision has been reached, the
contents of the Edit Buffer are loaded into main memory with the STORE
function. (Section 2.23)
2.10 PROGRAM SELECT MODE
The PROGRAM SELECT mode allows stored audio routing programs
(together with their associated PROGRAM SEND information) to be recalled
from memory. See section 2.30 for more on auxiliary PROGRAM SEND
capabilities. Stored programs are recalled as program numbers, and appear on
the left numeric display. One hundred program locations (00 through 99) are
provided for storage of routing programs. Program 100 is "bypass", and program
numbers 101 through 127 select program chains 1 through 27. (See Section
2.50 Program Chain Mode.)

AM/16-B Audio Switcher 11
2.11 SELECTING STORED PROGRAMS
To select a program, press the MODE SELECT button until the PROGRAM
SELECT LED comes on. Use the up/down arrows under the left display to
change the program number. When the desired program number is arrived at,
press ENTER. The MODIFIED LED will extinguish, and the new program will be
active.
In PROGRAM SELECT mode, the MODIFIED LED indicates that the
displayed program is not the currently active one-- that is, the one being heard.
To make it active, simply press ENTER. This two-step scheme allows one to
move from a program to another without hearing all the intermediate
possibilities.
Similarly, if it is not known which program is active, scroll through all of them
(which happens very quickly) and note the program number displayed at the time
the MODIFIED LED goes out; this is the current program.
2.12 REMOTE PROGRAM SELECTION
Programs can also be recalled through remote program change commands
without touching the front panel buttons. To receive them, set the AM-16/B to the
channel number on which the programs are to be transmitted. (See section 2.60)
When a program number is received, the switcher retrieves the program from
memory and configures itself accordingly. Incoming program commands are
ignored if the receive channel is set to "OF" (off).
2.20 PROGRAM EDIT MODE
The PROGRAM EDIT mode is used to create one or more simultaneous
source-destination connections within the switcher. Any of the sixteen sources
may be assigned to one or more destinations. In practice, each destination is
assigned to a single source, one at a time; the entire set can then stored in
memory as a program number which can be recalled later.
Constructing a set of audio paths is a two-step process. The source-
destination assignments are assembled in an "edit buffer", in which they are
created, auditioned, and modified, without actually changing the contents of the
crosspoint switches or program memory. They are then written to the crosspoint
switches as a second step. Once all of the audio paths are programmed, the
entire set can then be written to a program memory.
2.21 CONSTRUCTING AUDIO PATHS
First, select the program number to be edited, as described in Section 2.11.
Then press the MODE SELECT button until the PROGRAM EDIT LED lights.
The left display window indicates the program number being edited.

12 AM/16-B Audio Switcher
The right display indicates the DESTINATION to which an input will be
assigned. Select a destination first, using the arrow buttons under that display.
The center display indicates the SOURCE to be assigned to that destination.
Use the arrow buttons under the center display to select the source. Selection of
a source must be done after the destination has been selected. (It is helpful to
think of the Destinations as the locations of data, and the Sources as the data in
those locations. When you want to scan through the audio paths to see how
each is programmed, you step through the Destinations.) So far, the selected
program has only been modified in the Edit Buffer, and is neither being heard or
stored into memory.
Press ENTER to hear the new selection. The MODIFIED LED will light,
indicating that the signal paths just programmed are a modification of the
selected program. The new program may be stored as described below, or
abandoned by pressing either of the left display arrow buttons.
If no source is to be connected to a destination, the source display can
select the symbol "--" which indicates a mute. A shortcut to reaching the
"--" symbol is to press both arrow buttons under the center display at the same
time.
When a number of simultaneous audio paths are to be programmed at once,
it is faster to do it as follows:
Select 1st destination
Select 1st source
Select 2nd destination
Select 2nd source
Select last destination
Select last source
Press ENTER (MODIFIED LED comes on) or STORE
Perform STORE operation
It is always possible to make additional modifications to a program. Simply
select an additional destination, a source to go with it, and press ENTER to
audition it.
Note that it isn't necessary to audition new audio paths with the ENTER
button; if there is no question about their being correct, press the STORE
command to write them to memory at once.
2.22 MULTIPLE INPUT ASSIGNMENTS
An input can drive as many as sixteen outputs at once; each line is
individually buffered so there is no increase in loading on any input.

AM/16-B Audio Switcher 13
Audio "mults" can be created by assigning a single input to many outputs at
once. For example, Input #1 can be assigned to Outputs #1, 2 and 3:
INPUT NUMBER OUTPUT NUMBER
1 1
1 2
1 3
2.23 STORING EDITED PATHS AS A PROGRAM NUMBER
The entire set of sixteen audio paths can now be stored in memory.
Pressing the STORE button once will place the switcher in the PROGRAM
SELECT mode. Notice that the STORE PENDING LED is illuminated. This
means that a STORE operation can happen if STORE is pressed again. It has
not yet happened, but during the STORE PENDING interval, a new program
number may be selected as a location for the edited work. Use the arrow
buttons under the left window to select the new program number. Press STORE
again, and the STORE PENDING LED will go out. The new set of paths is now
stored as a program, with a numeric identity.
2.24 THE STORE-PENDING TIMER
In the "Store Pending" mode, the AM-16/B's computer is waiting to see if a
program number is selected and finally stored. Four seconds are allowed to
complete the operation. If at the end of that interval the STORE button has not
been pressed a second time, the store-pending mode will be exited. This "watch-
dog" prevents accidental damage to valuable programs that might occur if the
switcher was left armed.
2.25 MEMORY PROTECT
Memory protection is provided to prevent accidental erasure of valuable
programs in the switcher. It is a "global" function; that is, all programs are
simultaneously protected. It is also stored in non-volatile RAM, so that when
power is turned off, the protect function is remembered.
To set memory protect, enter the PROGRAM SELECT mode. Press the "up"
arrow button under the center display; the legend "Pr on" will appear. Memory
protect is now active.
To turn memory protect off, press the "down" arrow button under the center
display; the legend "Pr OFF" will appear. Memory protect is now disabled.
Should you attempt to store a program while memory protect is on, it will not
over-write the existing one, and will instead display "Pr on". To store, turn

14 AM/16-B Audio Switcher
memory protect off, and resume the store operation. Memory protect also affects
remote control STORE commands. Note that Memory Protect must be Off in
order to use the unit with an AM-16R Remote Control.
It is a good idea to use the "System Exclusive" data transfer capability to
create external backup copies of memory. This way, no matter what the cause
of damaged memory, it can be recovered. See Section 2.90.
2.26 COPYING PROGRAMS
It is often convenient to copy programs from their original memory location to
one or more new ones. Many programs will be similar to each other, and the
easiest way to create variations is by editing the original-- but under a new
program number.
NOTE: Programs may have identical audio connections, but posses different
auxiliary Program Send information. See Section 2.30.
To copy a single program, go to the PROGRAM SELECT mode and select a
program number. Press STORE once, and using the arrow buttons under the
program display, select a new number in which to place the program copy.
Press STORE again to write to memory.
2.27 THE BLOCK COPY FEATURE/MAKING MULTIPLE COPIES
To make multiple copies of a single program, enter the PROGRAM SELECT
mode, select a program number and press ENTER. Press BLOCK COPY.
Notice that the center display and right display appear. Use the arrow buttons
under the right display to select the upper limit first. Next, use the arrow buttons
under the center display to select the lower limit. The switcher will not allow an
improper range to be selected. Press STORE twice to copy to the new block of
memory.
2.28 USING BYPASS AS AN EDIT/COMPARE FUNCTION
Because the bypass program is instantly available from the front panel, it
can be used to compare the audio effect of two different programs. To do this,
load the BYPASS program with one selection, select any other program and
alternately turn BYPASS on and off, noting the difference.