Alcorn Mcbride AM-4 Reference Manual

AM-4 Digital Audio Machine

Hardware and Software Reference Manual

PLACE HOLDER

FOR THE BACK OF

THE FRONT COVER

DO NOT

PRINT!!!

ii Welcome!

Digital Audio Machine

User’s Guide

Alcorn McBride Inc.

Welcome! iii

Every effort has been made to assure the accuracy of the information contained in this manual, and the reliability
of the Alcorn McBride AM-4 Digital Audio Machine hardware and software. Errors can sometimes go
undetected, however. If you find one, please bring it to our attention so that we can correct it for others. Alcorn
McBride welcomes comments and suggestions on the content and layout of its documentation.

Applications described herein are for illustrative purposes only. Alcorn McBride Inc. assumes no responsibility
or liability for the use of these products, and makes no representation or warranty that the use of these products
for specific applications will be suitable without further testing or modification. Alcorn McBride products are
not intended for use in applications where a malfunction can reasonably be expected to result in personal injury.
Customers using or selling Alcorn McBride products for use in such applications do so at their own risk, and
agree to fully indemnify Alcorn McBride for any damages resulting from such improper use or sale.

This publication was created using Microsoft Word 2000 for Windows XP, Version 9.0.4119 SR-1. Camera­ready art and illustrations were produced using Corel DRAW!, Version 8.0

Digital Audio Machine™ is a trademark of Alcorn McBride Inc., all rights reserved.

Copyright  2006 Alcorn McBride, Inc. All rights reserved.

Hardware Design: Jim Carstensen, Jeremy Scheinberg

Firmware Design: Jim Carstensen, Chris Harden

Software Design: Jim Carstensen, Chris Harden, Scott Harkless, and Joy Burke

Documentation: Jim Carstensen, Chris Harden

Mechanical Design: Martin Chaney

Demo Material:

Demo Material:

“You Took Advantage of Me”
Performed by Tommy Bridges
Sr. Account Manager at Alcorn McBride
CD Trumpet Traditions available www.tradjazz.com
Copyright 2003 Tommy Bridges
All Rights Reserved.

Document Number 110-100974.00 Rev 2.7

Alcorn McBride Inc.
3300 S. Hiawassee, Suite 105
Orlando, Florida 32835
[phone]
FAX: [phone]
Internet: http://www.alcorn.com
e-mail: [e-mail]

iv Welcome!

Table of Contents

Welcome! ............................................................ 1

Features.......................................................... 2

Technical Support ......................................... 2

Quick Start Guide ............................................... 3

Playing the Demo Material ........................... 3

Controls and Indicators...................................... 5

Test Button..................................................... 6

Status LED ..................................................... 6

Configuration DIP Switch ............................ 7

Voltage / Contact Closure Select Switch............. 7

Ground Lift ......................................................... 7

Write Protect ....................................................... 7

Serial Port Mode ................................................. 8

Volume Control and Audio Outputs............ 9

Balanced Outputs (optional) ............................... 9

Amplifier Outputs (optional)............................... 9

Ethernet Interface (optional)...................... 10

Power............................................................ 10

Serial Port: DB-9 Connector ...................... 10

Parallel Port: DB-37 Connector................. 11

Controlling the AM-4 ....................................... 12

Parallel Control ........................................... 12

Parallel Inputs ................................................... 12

Parallel Outputs................................................. 16

Simple Serial Control .................................. 17

Select File.......................................................... 18

Play ................................................................... 18

Loop Play .......................................................... 18

Play File ............................................................ 18

Loop File........................................................... 19

Pause ................................................................. 19

Reset.................................................................. 19

Advanced Serial Protocol ........................... 20

Acknowledge Codes..................................... 23

Serial Error Codes....................................... 23

Ethernet Control ......................................... 23

Hardware and Software Requirements.............. 23

Control Message Format ................................... 24

Control Message Checksum.............................. 24

UDP Message Layer.......................................... 25

Control Message Response ............................... 25

Fields in Detail .................................................. 30

Restrictions........................................................ 33

Comments & Whitespace .................................. 33

Order of Operations ........................................... 33

Double Occupancy ............................................ 34

Schedule Builder ..........................................36

Uploading New Schedules to the AM-4 ............ 40

File Types and Storage ..................................... 41

Supported WAV File Formats ....................41

Making MP3 Files ........................................42

Encoding............................................................42

Quality...............................................................42

Compact Flash Media.................................. 42

Formatting the Compact Flash........................... 43

Getting Files Into The AM-4 .......................44

Copying Files Directly Using a PC....................44

Copying Files Using an FTP Connection ..........45

Required File Name Formats......................46

Play List Files ...............................................47

Overview ........................................................... 47

Special Play List Command Summary...............48

Random Playlists ............................................... 49

Example Play List.............................................. 49

Example Play List with BGM Mode.................. 50

Example Play List with Output Relay Control ..50

Power Up Operation..........................................51

Updating Your Firmware............................51

GPS Operation ..................................................52

GPS Builder..................................................53

Program Description.......................................... 54

Connection Diagram.......................................... 57

Program Operation ............................................ 57

Operating the AM-4 with GPS .......................... 59

Connecting an LED or LCD Sign...................... 60

Troubleshooting Guide / FAQ ..........................61

Mechanical Information...................................65

Mechanical Dimensions..................................... 65

Surface Mounting .............................................. 65

Rack Mounting .................................................. 67

Specifications .................................................... 69

Index.................................................................. 70

Scheduler .......................................................... 27

File Format / Tutorial ................................. 27

Events................................................................ 27

Welcome! v

™.

replaces tape machines, CDs and solid state audio

quality,

Welcome!

A Compact Flash card
is included with your
AM-4.

Thank you for purchasing The Alcorn McBride AM-4 Digital Audio Machine
The AM-4 Digital Audio Machine
players in permanent audio playback installations, providing hours of high­maintenance-free digital audio.

The AM-4 Digital Audio Machine plays MP3 audio files from rugged Compact Flash
media cards. Any size up to 2 Gbytes can be used, providing hours of MP3 audio.

The AM-4 Digital Audio Machine can be serially controlled using standard, ASCII­based Pioneer Laser Disc protocol, or via an optional Ethernet connection. Parallel
control is also possible through the use of contact-closures or voltage inputs.

Please browse the table of contents or index before jumping in, as we have included
valuable sections like one on getting started right out of the box playing audio. Also,
we have included a section that discusses creating of MP3 material and where to get
encoders.

We would like to provide you with the latest Firmware updates for your AM-4 and
notify you when additional features become available. Please visit
http://alcorn.com/library/lists/subscribe.html to sign up for automatic notifications of
Firmware upgrades. You can also visit

http://www.alcorn.com/support/firmware.html to check for upgrades.

Have fun with your new AM-4 Digital Audio Machine!

Welcome! 1

Features

The AM-4 Digital Audio Machine offers a wide range of features including:

• Plays MP3 and WAV files.

• Plays from Compact Flash Storage.

• Near instantaneous access to files.

• Stores over 500 Tracks.

• Sophisticated Play List and Real-Time Clock scheduling capabilities.

• Serial RS-232C, Parallel, or optional UDP control over Ethernet.

• Optional Speaker Level outputs (20Wx2).

• Optional Balanced outputs.

• Optional S/PDIF Digital Audio output.

• GPS positional triggering capability.

Technical Support

You can obtain information about specifying, installing, configuring, updating and
programming your Alcorn McBride AM-4 Digital Audio Machine from several
sources:

For…

Telephone Support

Fax Support

e-mail Support

Firmware Updates

Contact… When?…

[phone] M-F 9am–6pm (EST)

[phone] M-F 9am-6pm (EST)

[e-mail] Any Time

http://www.alcorn.com/support Any Time

2 Welcome!

Quick Start Guide

Throughout this manual you will find detailed discussions on all the features of
the product. But below are a few points to get you going with the AM-4 Digital
Audio Machine right out of the box!

Playing the Demo Material

Your AM-4 Digital Audio Machine comes complete with a Compact Flash Card
already loaded with demo material. File number one is an MP3 audio file. You can
play it by doing the following:

• Don’t plug anything in yet.

• Grab a screwdriver and remove the two screws holding the Compact Flash

Drive cover plate, to reveal the unit’s Compact Flash Socket.

Media Cover Plate

• Remove your Compact Flash Card from its protective packaging, and place

it in the unit’s Compact Flash socket. Push it in until the ejector button
comes out. As a side note, to avoid damage to the unit, never ship these
units with the Compact Flash card inside the unit.

• Connect the RCA jacks to an amplifier capable of playing line level in

signals, or if your AM-4 is equipped with the speaker amplifier option,
connect (non-powered) speakers (20W min power handling) to the screw
terminals on the back of the unit.

• Make sure the volume control on the rear of the unit is turned at a

reasonable level. (The groove in the knob should be almost vertical, rotated
slightly to the left.)

• Plug in the unit with the included power supply. There is a status LED next

to the Compact Flash socket that should blink briefly while it accesses the
Compact Flash card.

• Press the round black test button located on the front of the unit beside the

LED.

• Verify you see the status LED turn Green. You should be hearing audio! If

not, turn up the volume a little. There is a diagram on the next page, and a
Troubleshooting guide in the back of this manual for your assistance.

Quick Start Guide 3

4 Quick Start Guide

Socket

Connector

(option)

Configuration DIP

Switch

Audio Outputs

Output

Balanced Audio

Outputs

Controls and Indicators

The AM-4 Digital Audio Machine provides controls that can accommodate a wide variety of installations. The
front panel incorporates a test button, status indicator, Compact Flash Card slot. The rear panel provides the
line-level audio outputs and control connectors. Depending on which option cards are installed, the rear panel
can also contain speaker-level outputs or balanced and S/PDIF digital audio outputs, or an Ethernet jack.

Test Button

Status LED

Compact Flash

Parallel Control

Ethernet Jack

Balanced Audio Module Option

Power

Input

L/R Line-Level

Volume RS232

Connector

Digital Audio

Amplifier Module Option

Speaker Outputs

Controls and Indicators 5

format the Compact

Test Button

Be sure that the Write
Protect DIP switch is
OFF before trying to

Flash.

Use your PC to format
Compact Flash cards
larger than 2G in size.'

A recessed push-button is located on the front of the unit. This button is used to
“test” play the unit and will play the first file found on the media. It could be a
either a sound file or a playlist.

The test button is also used to format the Compact Flash card. If you hold in the test
button while inserting the card a format operation will take place. While formatting,
the Status LED will turn green. The operation takes only a couple of seconds.

Important: Formatting will result in the loss of all data on the Compact Flash
card.

Status LED

A dual-color LED located on the front of the unit indicates status.

LED Behavior LED Meaning

Steady green Playing

Steady orange Paused or Waiting

Steady red Muted

Flashing red Fault

Flashing green Drive Access or GPS input active

Flashing green/red Updating OS

Off Idle

The LED blinks green briefly during initialization and while accessing the compact
flash media.

6 Controls and Indicators

Configuration DIP Switch

Voltage / Contact Closure Select Switch

A 4 key DIP switch (red with white keys) is located on the rear of the unit below the
DB-37 Control Connector. Its first key selects between voltage inputs or contact
closures for the discrete controls. More information on these inputs may be found in
the section entitled Rear Panel Connectors. For contact closure mode, push the DIP
switch #1 to “ON”.

Ground Lift

Be sure to configure the
AM-4 Digital Audio
Machine’s switches
before rack mounting
the units, or the
switches may be
inaccessible.

Write Protect

In the event of AC hum or noise caused by potential ground loops, the second key on the 4
key DIP switch, may be opened to isolate the AM-4 Digital Audio Machine’s ground from its
chassis. For ground lifting, push the DIP switch #2 to OFF.

You can protect the contents of the Compact Flash card by turning on the third key on the 4
key DIP switch. With this switch ON, all write operations including file copying, file
deleting, renaming, and formatting are disabled. For normal write operations, turn this switch
OFF.

DISABLE ENABLE

Controls and Indicators 7

Serial Port Mode

Refer to the GPS section
in this manual for
details.

For normal serial port control, turn off the fourth key on the 4 key DIP switch. To
enable GPS mouse operation, turn this switch ON.

8 Controls and Indicators

provide a standard

are provided on combination ¼ inch XLR jacks, and the S/PDIF output is on an RCA

jack.

+

_

+

_

Volume Control and Audio Outputs

To increase volume
rotate the post
clockwise.

The RCA outputs

-10dbu unbalanced
signal.

Please refer to the
Advanced Serial
Control section of this
manual for details.

The volume control is the gray colored post protruding from the rear of the unit next
to the RCA jacks. It controls volume for the RCA line level outputs, as well as for
the optional speaker or balanced outputs. It does not control the volume on the
optional S/PDIF digital audio output.

If using power speakers, you may need to adjust the volume control to about 90
degrees from Off for an optimum. You can then adjust the volume on the powered
speakers.

You can also control the volume via serial or UDP commands. When using the serial
or UDP commands to control volume, you might want to set the manual volume
control knob at maximum otherwise full output volume will not be obtainable.

Balanced Outputs (optional)

The balanced output
level is +4dBu. The
S/PDIF output is a
standard IEC-958
signal.

The AM-4 Digital Audio Machine can be ordered with a module which supplies
balanced line-level outputs and a S/PDIF digital audio output. The balanced outputs

Amplifier Outputs (optional)

Be sure to pay attention
to the speaker polarity
while making
connections.

Controls and Indicators 9

If equipped with the amplifier option, each amplifier output is capable of up to
20Watts of power into 8 ohms. The line level outputs work along with the speaker
level outputs.

IMPORTANT NOTE: Do not bridge the speaker outputs or damage will occur.

Ethernet Interface (optional)

pro

Activity (Yellow)

The AM-4 Digital Audio Machine can be ordered with an optional Ethernet Module
which adds control and file transfer capabilities to the AM-4 over a standard Ethernet
connection. The Ethernet interface is provided on a standard RJ-45 jack.

Two LED indicate Ethernet status as shown below. The Green LED should be on
whenever an active Ethernet connection is detected, and the Yellow LED flashes
whenever Ethernet activity occurs.

Power

Link (Green)

Please refer to the sections in this manual explaining FTP and UDP operation for
more details on Ethernet functionality.

The power input is a 2.5x5.5x10mm barrel connector with center pin (+) and the
outer rim (-). The AM-4 Digital Audio Machine requires 12.0 VDC to 25.0 VDC at 2
Amp. This is useful for mobile applications where an automotive battery is used to
power a Compact Flash Card or Compact Flash Card hard drive. DO NOT EXCEED
THE SPECIFIED INPUT VOLTAGE RANGE. An external 100-250 VAC 50/60Hz
input universal switching power supply is provided with the unit.

A plastic strain relief can be threaded through slots near the power input jack to
secure the barrel connector if the AM-4 is installed in a high-vibration environment.

Serial Port: DB-9 Connector

A serial cable is

vided with each AM­4 Digital Audio
Machine.

10 Controls and Indicators

This input is a standard DB-9 male RS-232C connector, intended to be connected to
a PC using a straight-through (not null-modem) 9-pin cable. The pinout appears
below.

Pin Function

2 TXD (data from AM-4

Digital Audio Machine)

3 RXD (data to AM-4 Digital

Audio Machine)

5 GND

The DIP switch located on the side

pin connector can be

Parallel Port: DB-37 Connector

Be sure to configure the
AM-4 Digital Audio
Machine for contact
closures or voltage
inputs before
connecting any wires.

Note: The Fault output
relay will be active
(closed) immediately
after power-up
indicating that power
was lost. The first valid
command causes the
relay to open.

This connector provides all of the signals needed to interface to the AM-4 Digital
Audio Machine. Files numbered 1 through 15 of the AM-4 Digital Audio Machine
may be played, paused or stopped using eight parallel inputs located on the rear
connector. These inputs may be either contact closures such as momentary buttons,
or voltage inputs from a controller such as a PLC.
of the unit next to the connector selects between the two input types. More
information on these inputs may be found in the section entitled Parallel Control.

Two dry-contact relay outputs provide Fault and Playing status (closed when active).

A current-limited (100mA max.) 5VDC output can be used to light external LED
indicators, and an extra power supply input exists so that the 37­used to supply power instead of the barrel jack. Any of the ground connections may
be used for the return.

The pinout of the Control Connector is shown below:

Pin Function Pin Function

1 Mute 20 Ground

2 Pause (see Note 1) 21 Ground

3 Stop 22 Ground

4 Loop (see Note 2) 23 Ground

5 File Select 1 24 Ground

6 File Select 2 25 Ground

7 File Select 4 26 Ground

8 File Select 8 27 Ground

9 Playing Output (contact 1) 28 Playing Output (contact 2)

10 Fault Output (contact 1) 29 Fault Output (contact 2)

11 Mute (voltage input) 30 5 VDC output, 100 mA max.

12 Pause (voltage input) 31 Ground

13 Stop (voltage input) 32 Ground

14 Loop (voltage input) 33 Ground

15 File Select 1 (voltage input) 34 Ground

16 File Select 2 (voltage input) 35 Ground

17 File Select 4 (voltage input) 36 Ground

18 File Select 8 (voltage input) 37 Ground

19 Extra Power Supply Input

Controls and Indicators 11

Note 1: If the Pause input is activated on power-up the Play Next mode is activated
(Please refer to Parallel Control chapter for details).

Note 2: If the Loop input is activated on power-up the Playlist & Volume
Increment/Decrement mode is activated (Please refer to Parallel Control Chapter for
details).

Controlling the AM-4

Parallel Control

Parallel Inputs

Be sure to configure the
DIP switch before
connecting any wires.

The AM-4 Digital Audio Machine can be controlled using either contact closures or
voltage inputs on the female DB-37 Control Connector. DIP switch number 1 selects
between the two input types. Voltage inputs are rated for 24 VDC. The table below
describes the function of each input.

Function Voltage

Input
Pins

Mute 11(+),1(-) 1,20 Ramps the audio to zero volume and

Pause 12(+),2(-) 2,21 Pauses the file currently playing. Pause is

Stop 13(+),3(-) 3,22 Stops the file currently playing. If the file

Loop 14(+),4(-) 4,23 Causes the selected file to loop indefinitely

File Select 1 15(+),5(-) 5,24 Binary-encoded input plays files 1-15.

File Select 2 16(+),6(-) 6,25 Binary-encoded input plays files 1-15.

File Select 4 17(+),7(-) 7,26 Binary-encoded input plays files 1-15.

File Select 8 18(+),8(-) 8,27 Binary-encoded input plays files 1-15.

Contact
Closure
Pins

Description

maintains it there as long as Mute is
asserted. When Mute is released, audio
returns to full volume.

maintained as long as it is asserted. Play
will resume when the file is commanded to
play again.

is a Play List, it is aborted.

from beginning to end. If the file is a Play
List, all tracks will be played and then the
file will loop. The state of this input is
examined at the start of each file.

The binary file select inputs are used to play the first 15 files. These inputs may be
contact closures or voltages, depending upon the input select DIP switch described in
the Configuration DIP switch section of this manual. The inputs are change-sensitive;
that is, when a change is detected, the new file will be played. It is therefore
important that the four bits change at the same time.

If the same file number is selected repeatedly it will normally interrupt itself and
begin again. When processing a Play List, if the Play List is selected repeatedly it
advances from entry to entry within the list – unless the “Uninterruptible” flag has
been set (see the Play List section for more information).

12 Controlling the AM-4

The table below shows the binary combinations possible, and what file they select:

8 4 2 1 File

Off Off Off Off None

Off Off Off On 1

Off Off On Off 2

Off Off On On 3

Off On Off Off 4

Off On Off On 5

Off On On Off 6

Off On On On 7

On Off Off Off 8

On Off Off On 9

On Off On Off 10

On Off On On 11

On On Off Off 12

On On Off On 13

On On On Off 14

On On On On 15

The loop input is read
at the start of the file.

For example, connecting pins 8 and 27 together with the slide switch set in the
contact closure position will cause file 8 to play.

The file will be looped if the loop command is asserted when the file is played. If the
file is a Play List, all tracks will be played and then the Play List will loop.

The file select inputs may also be strapped to automatically play a file on power-up.
That file number takes precedence over any autoexec files that may be on the drive
(see power up operation). If an autoexec file exists and the loop input is strapped, it
will play indefinitely.

The simplest possible configuration is to connect four switches to the unit’s four file
select lines. These switches will play files 1, 2, 4 and 8. (The missing file numbers
need not exist.) Sixteen switches may be connected without an external controller, by
using a diode matrix. One side of each switch is connected to a wire that goes to
signal ground. The other sides of the switches are connected through signal diodes,
such as a 1N914 or 1N4148, to the file select inputs.

Special Modes

Play Next Mode

If the Pause input is activated on power-up, Play commands (and File Selects) will
operate as Play Next, thereby not interrupting the currently playing sound and instead
cue up the next sound to play when the current sound has finished.

Controlling the AM-4 13

Playlist Increment/Decrement & Volume Control
Mode

If the Loop input is activated on power-up, the File Select inputs operate as Playlist
and Volume Increment/Decrement as shown here:

File Select 1 = Increment Playlist Number

File Select 2 = Decrement Playlist Number

File Select 4 = Increase Volume

File Select 8 = Decrease Volume

This allows the use of just two toggle switches for playlist selection and volume
control.

14 Controlling the AM-4

SYMBOLS:

1

2

1N4148

1

2

DB37 Contact Closure Diode Network Diagram for 15 Clips

Note:

please notify Alcorn McBride.

Clip 3

Clip 8

Clip 9

Clip 10

Clip 11

Clip 12

Clip 15

Clip 14

Clip 13

Ground

Using a terminal block
to hold the diodes
makes the wiring neater.

I/O connector

1
20
2
21
3
22
4
23
5
24
6
25
7
26
8
27
9
28
10
29
11
30
12
31
13
32
14
33
15
34
16
35
17
36
18
37
19

For example, the following circuit allows switches to select files 1 to 15:

1 2

1 2

12
12

1 2

1 2

12
12

1 2

12

12

1 2

12

12

12

1 2

1 2

Clip 1

Clip 2

SWITCH

Clip 4

Clip 5

Clip 6

Clip 7

The 37pin connector
on the diagram is

12

1 2

12

inverted from what you
see when looking at
the back of our

12

1 2

12

12

1 2

12

12

12

1 2

12

12

1 2
12
12

12

1 2
12
12

12

1 2
12
12
12

If you don’t want to wire this circuit yourself, we have a cheap, discrete control
breakout-board that lets you directly select all 15 files and the control contacts like
Play, Stop, etc… without touching a diode or your soldering iron. Look for the
Input Expander at www.alcorn.com for details.

product.

This is so that
you can see what it will look
like when making a cable
assembly. Remember to
have the I/O setting to
Contact Closure.

You may use this as a guide
for building a diode network,
but it is only a reference.
We are not responsible for
any obvious errors in the
diagram. Use logic to verify
your setup is correct. If you
find errors with this diagram,

You can help us help other
customers with the same
question.

Controlling the AM-4 15

Voltage

Parallel Outputs

Voltage inputs, such as from a PLC, could be wired this way:

I/O CONNECTOR

1
20
2
21
3
22
4
23
5
24
6
25
7
26
8
27
9
28
10
29
11
30
12
31
13
32
14
33
15
34
16
35
17
36
18
37
19

CONNECTOR DB37

Contacts

Switch set
to voltage

PLC

24 Volt Output 1

24 Volt Output 2

24 Volt Output 4

24 Volt Output 8

Ground Reference

Diodes are not needed, since the PLC can actuate any combination of lines desired.

Two status outputs are provided. They are dry contact closures rated at 24 VDC and

0.9 amp max. Their function is described below.

Function Pins Description

Playing 9,28 Closed when the unit is playing.

Fault 10,29 Closed when the unit detects a fault

condition.

You can also control these outputs with serial “Relay” commands. One practical
application of this is to embed the “Relay” commands in a playlist along with “Play
Sound” commands. This way you can close or open a relay when a sound plays or
stops.

Please refer to the Miscellaneous Commands under Advanced Serial Protocol for
details on how the “Relay” command works, and to the Playlist Section for an
example playlist which demonstrates the use of the “Relay” command.

16 Controlling the AM-4

place on Port 2639.

Simple Serial Control

For serial communications
with a PC or an Alcorn
McBride Show Controller, use
the supplied straight-thru (not
Null) serial cable supplied
with the AM-4.

UDP communications take

The AM-4 Digital Audio Machine may be controlled using serial RS-232C
messages via the rear DB-9 Programming Connector, or with UDP (User Datagram
Protocol) messages via the optional Ethernet interface. The serial data format is
9600,N,8,1: 9600 baud, 8 bits/byte, no parity, with one stop bit.

For UDP operation you must first set the IP address, Subnet Mask, and Gateway
address (if applicable) by issuing the corresponding serial commands. Please refer
to the Advanced Serial Protocol section in this manual for specific details on what
commands are used to set up the Ethernet interface.

AMI Terminal is a Windows application that can be used to control the AM-4 (as
well as other Alcorn McBride equipment). It is available on the Alcorn McBride
Website at http://www.alcorn.com/support/software.html/amiterm.zip.

The control protocol is ASCII-based, and many commands are identical to Pioneer
Laser Disc protocol. Upper or lower case characters can be used interchangeably.

The most commonly used serial commands for playback are:

Command Function

Select File Select a file

Play Play the selected file

Loop Play Play the selected file over and over

Play File Same as Play, except file is specified

in command

Loop File Same as Loop Play, except file is

specified in command

Pause Pause at current location. The Play

Command resumes playback.

Stop Stops playback.

The details of these commands are listed in this section. Many other commands are
also possible, and are summarized in the section entitled Advanced Serial Protocol.
Unless otherwise noted, all of these commands operate on any type of file, whether
audio track or Play List. Throughout this manual <CR> means carriage return, a byte
with the hexadecimal value 0D.

Controlling the AM-4 17

Select File

Description: This command causes the AM-4 Digital Audio Machine to select the specified audio

track or Play List on the currently selected media. Once this command is sent, the
next Play command causes the specified file to play from the beginning. The unit
defaults to file #1 at power-up, unless an autoexec file exists. When receiving this
command, the AM-4 Digital Audio Machine always looks for the file on the currently

selected drive.
Command Bytes: nSE<CR> or nnSE<CR> or nnnSE<CR>
where n, nn, or nnn is the file number in ASCII.
Message Response: R<CR>
Comments: This is similar to the “Search to Address” command in chapter addressing mode used

in Pioneer Laser Disc protocol. The maximum file number is 511.
Examples: Select file 215. 215SE<CR>
Select file 4. 4SE<CR>

Play

Description: This command causes the AM-4 Digital Audio Machine to play the file which was

specified with the “Select File” command. If a track is paused, this command resumes

play. If this command is issued while a Play List is being played, the AM-4 Digital

Audio Machine will skip to the next track in the Play List and play it. This command

sends a response when it is executed, and another when the playback is complete.
Command bytes: PL<CR>
Message Response: R<CR>
Completion Response: <CR>

Loop Play

Description: This command causes the AM-4 Digital Audio Machine to play the file specified by

the Select File command and loop back to the beginning. If the file is a Play List, all

of the tracks in the Play List will be played and then the entire Play List will restart.
Command bytes: LP<CR>
Message Response: R<CR>

Play File

Description: This command is the same as the Play command, except the file number or name is

specified as part of the command so no prior Select File command is required.
Command bytes: nPL<CR>
Where n is the file number or name (surrounded in quotes).
Example: 3PL<CR> plays file number 3.
Example: “bark.mp3”PL<CR> plays the file named “bark.mp3”
Message Response: R<CR>
Completion Response: <CR>

18 Controlling the AM-4