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Original package includes interface cable

2 Bit Systems Ltd.

The Midi Interface

for Atari XL/XE machines

MidiMaster is a full Midi interface for the Atari 8-bit
machines and may be used with any Midi synthesiser to create or play music. MidiMaster allows real time recording on an 8-track sequencer and includes a music player for AMS files, hundreds of which are available in the public domain.


Also included are voice patch editors for Casio CZ and Yamaha DX series synths.


MidiMaster comes complete with a full manual which explains exactly how you can get your Atari to make music the like of which you have never heard before!


MidiMaster Operating Instructions and User Guide

by John S. Davison

MIDI, the Musical Instrument Digital Interface, has caused a revolution in the world of music making. It was originally designed as a standard interface to allow electronic instruments from different manufacturers to easily interconnect with each other, so that for instance, the keyboard on one could play the sound generation circuitry of one or more others. It uses a standard method of physical connection, namely a 5-pin DIN plug and socket, and a standard set of "messages" which can be sent across the interface and acted upon by any or all of the electronic instruments so connected.

The technology in electronic musical instruments is very similar to that used in computers, so it wasn't long before some bright spark fitted a MIDI interface to a computer. OK, so the computer can't produce music as well as the instruments can, but it is rather good at storing and processing digital data, which is what passes through the MIDI connections. Once the computer interface was available all sorts of musical applications began to appear on the scene, allowing the computer to be used for many different music related tasks. These included such functions as recording and playing back music, and producing printed scores from data played into the computer from a standard piano-style electronic keyboard. It also helped make the operation of the musical instruments themselves easier, such as programming them to produce new sounds and to store and catalogue those sounds.

The first computer to feature a MIDI interface built-in as standard was the Atari ST, which is why it can now be found in most of the world's professional recording studios. Even today, years after the ST was launched, there are still very few computers supplied with MIDI fitted as standard, although many can now be retrofitted with MIDI capabilities using separate add-on accessories.

Until now the Atari 8-bit machines have had to rely on their internal sound chip to generate musical sounds, and excellent though this is, it's no match for the sound produced by a proper electronic instrument. However, there have been several good musical applications produced for the 8-bit machines, notably Advanced Music System (sadly no longer available), and Atari's own Music Composer cartridge (which is available still). Wouldn't it be nice if the 8-bit machines could have a proper MIDI interface and make use of some of that existing software? By purchasing MIDI Master you've already answered that question!

MIDI Master is a package of hardware and software designed to allow you to control an electronic musical instrument, such as a synthesiser or drum machine, via MIDI. It was originally designed and produced by 2-Bit Systems, who have since gone on to fame (and fortune?) producing the Replay series of sampling hardware for the ST and other computers. It was probably ahead of its time, as no-one really took much notice when it was offered for sale by 2-bit Systems, so eventually they withdrew it from the market.

I first came across a reference to MIDI Master in a music magazine, and a phone call to 2-Bit Systems established it was no longer available. However, they did manage to find a sample for me to try, and I was so impressed at what it did for such a low price that I just had to bring it to the attention of Page 6 Publishing with a view to saving it before it disappeared forever. Les Ellingham was impressed too, and managed to negotiate a deal with 2-Bit Systems to make MIDI Master available to readers of New Atari User.

Before you go on to use it, please allow me to set your expectations at an appropriate level. This is a very simple package, as you might guess from the price. Don't expect it to have all the facilities of an ST MIDI system, because you'll be disappointed if you do. Top class MIDI software is VERY expensive - you can pay hundreds of pounds for a first rate sequencer alone. Treat MIDI Master as an introduction to MIDI, as something to cut your MIDI teeth on, and you won't go far wrong.

This documentation is a rewrite of the rather sparse original MIDI Master instruction booklet, based on my own personal experience of using the package. I thought this necessary after using MIDI Master for a while and discovering several confusing aspects, certain features that didn't work as expected, and one or two bugs. I've tried to point out these anomalies wherever possible, to save you the frustration of discovering and solving them yourself. However, you may discover different problems, particularly if you use different synthesisers to those I use, which in turn were different from those used by the software developers. My experience with MIDI Master is based on Yamaha PSS-680 and YS-200 instruments. The developers used a Casio CZ101 and Yamaha DX27 I believe, and designed the package with these in mind. When considering this, and its low cost, it's probably inevitable that anomalies will arise when used with different synthesiser equipment.

Having said all that, MIDI Master is capable of some very good results if you're prepared to put some effort into it, especially if used in conjunction with ancillary programs such as Advanced Music System or Music Composer (more of which later).

The programs themselves may look complex from their appearance, but they're really quite simple to use once you get to know them. To help you learn I've included simple step-by-step instructions where appropriate. I suggest you start by reading through this manual and follow the instructions as you encounter them. This should give you a thorough familiarisation in all aspects of the MIDI Master package.

OK, it's now time for YOU to join the MIDI revolution, so let's move on to see how to set up and use MIDI Master. I wish you many happy hours of music making.

John S Davison 

13 December 1989




The MidiMaster Package

The hardware part of the package consists of a lead with an Atari serial port connector (Molex plug) at one end and two 5-pin DIN plugs at the other. However, the interface is NOT just a cable. What you can't see is the electronic circuitry, which is cleverly built into the casing of one of the plugs.

The hardware alone is not enough to enable you to make music - you need some application software to take advantage of it. Accordingly, the package includes a disk containing three types of MIDI software. First there's an eight track sequencer, which enables you to record music in real-time directly from your synthesiser's keyboard, to make various changes to it using the computer, and to play back the result through your synthesiser again. Secondly, there are two music player programs, which enable you to play back music created with separate music composition programs, namely the Advanced Music System or Music Composer programs mentioned earlier. If you don't have either of these programs please remember that disks of music data files produced using Advanced Music System are available as Public Domain disks from Page 6 Publishing. Most of the files play perfectly through MIDI Master's player program, although one or two do have problems. Finally, the package includes two voice patch editor programs. These enable owners of Casio CZ101 and Yamaha DXI00 (and similar) synthesisers to create new sounds (voice patches) for their instruments, and to download them to those instruments or store them on disk for future use.

Hardware Requirements

To use MIDI Master you must have the following equipment: 

An Atari 8-bit machine with at least 48K storage. 

A 5.25" disk drive.
A MIDI equipped electronic musical instrument.

For most people the electronic musical instrument will be a "home keyboard", i.e. a piano-style keyboard unit containing a synthesiser, amplifier and speakers. However, you can use virtually any type of electronic musical instrument as long as it has those vital MIDI ports. It MUST be equipped with MIDI IN and MIDI OUT ports - without them the instrument is useless as far as MIDI Master is concerned. Yamaha, Casio, and other manufacturers produce suitable products costing from about 150. Note that for simplicity the term "synthesiser" is used from hereon in this booklet to generically describe all such instruments.



The MIDI Master cable has an Atari serial interface plug at one end and two 5-pin DIN plugs at the other. If you look at the DIN plugs you'll see one is marked with an "I" and the other an "0". These stand for MIDI IN and MIDI OUT respectively. Make sure the synthesiser, computer, and attached peripherals are turned off then insert the plug marked "I" into your synthesiser's MIDI IN socket, and the one marked "0" into its MIDI OUT socket.

Next, insert the Atari serial plug on the other end of the cable into a spare serial port on your 8-bit system. For most people this will be the unused port on the back of the disk drive.

Note that if your system includes a cassette recorder with a spare serial port on the back, it's recommended that you DON'T connect MIDI Master to this. The reason is that in some circumstances it's possible for MIDI data from a synthesiser to interfere with tape loading and saving. It's safer to disconnect the cassette unit and connect MIDI Master into the port thus freed.




A sequencer gives you the ability to capture and record MIDI data generated by playing on a MIDI equipped musical instrument, here assumed to be a keyboard. Note it's NOT the musical sounds that are recorded, but rather the data describing which keys you pressed to achieve it. Once recorded, the process may be reversed and the data played back into the instrument, when its associated sound generation (synthesiser) circuitry will reproduce the original performance.

The MIDI Master sequencer has eight tracks, which means you can separately record up to eight individual voices in a musical piece (known as a "song" in MIDI terms) and play them back simultaneously. This allows you to build up complex musical arrangements from relatively simple parts. In this respect it behaves rather like an eight track tape recorder.

Loading Instructions

Ensure the computer and synthesiser are correctly connected via the MIDI Master cable as described earlier.

Switch on the synthesiser.

Switch on the disk drive and insert the MIDI Master program disk. 

Hold down the computer's OPTION key and switch on the computer's power. This will boot up DOS with BASIC disabled. After a short while the standard Atari DOS menu will be displayed on the monitor screen.

Key in L and press the Return key to select the DOS program load option from the menu. You will then be prompted to enter the name of the file containing the program.

Key in SEQ and press Return. The Sequencer program will now load, and when complete the program's operating screen will appear. The system is now ready for use.

The Operating Screen

The sequencer's one and only screen is divided into three sections - a status line at the top; a block of track status information in the middle, containing one line for each track; and a message/input line at the bottom. Let's look briefly at each of these in turn.

Status Line - this shows the metronome speed and amount of free input buffer space remaining.

METRONOME speed is used to provide timing when recording, and generates an audible click through the monitor's speaker. The time between each beat is variable between approximately 0.1 second and 3.1 seconds in 0.1 second steps. It can be increased or decreased by pressing the > or < keys respectively. A value of zero disables the metronome.

BUFFER shows how much memory is left for storing MIDI message data. Each note played on the music keyboard generates a Note On message when you press the key, and a Note Off message when you release it. The keyboard sends these messages to the computer via the MIDI Master interface cable, where they are captured and stored in memory.

Track Status Block - this shows the current status of each of the eight sequencer tracks on which you can record. Each track can carry a monophonic music line, i.e. a sequence of musical notes with just one note sounding at any point in time. Therefore it's not possible to record musical chords on a single track, but chords can be handled by using several tracks simultaneously, as we shall see later.

New values may be entered in the status fields to change the way the sequencer operates. To alter the values use the cursor (arrow) keys to move the cursor to the field you wish to alter, then overtype the data there with the required value. There's no need to use the Control key with the arrow keys to move the cursor, just use the appropriate arrow key on its own.

The status line for each track shows the following:

REC shows the MIDI channel from which data will be taken to record onto this track when the Record function is selected. Its range is 00 to 16, with 00 disabling recording on this track.

PLY shows the MIDI channel on which data on this track will play when the Playback function is selected. Its range is 00 to 16, with 00 disabling playback from this track.

PGM indicates the MIDI program number that will be transmitted to the synthesiser (for the channel selected above) before any notes on the track are played. Its effect is to select the voice with this number on your synthesiser. Any notes subsequently played from this track will sound with the selected voice. Its range is 000 to 128, but the actual sound selected varies depending on the synthesiser you are using. Note that a value of 000 results in NO program change message being sent - the synthesiser will play whatever voices it was previously set with. This means the program change numbers run from 1 to 128, whereas some synthesisers (such as the Yamaha PSS series) have their voices numbered from zero. Accordingly, the program change numbers will be one out and you'll have to allow for this. For instance, to get voice 00 to sound you have to request voice 01, for voice 17 request voice 18, and so on.

TRP is used when you want to move all the notes on a track or down in pitch without having to play them from the keyboard again. This is known as transposition. The value shows the number of semitones up or down you want the notes on this track transposed. Its range is -99 to +99, negative for down in pitch, positive for up. Press the Space Bar to change the sign.

REP controls the number of times a track will repeat once it has played.

LEAD allows you to delay the start of a track. The lead in time is nominally in units of 100th of a second.

GAP allows you to insert a delay between repetitions of a track. Delay time is nominally in units of 100th of a second.

Message Line - this line is used to display any messages generated by the program. The messages are simple, but usually self explanatory. Hint - the message referring to "disk error" is usually caused by the user spelling a file name incorrectly.

Sequencer Controls

The sequencer is controlled via six commands, and these are triggered by six keys as follows:

L to LOAD all eight tracks of a song from disk, complete with status field values set at the time of saving.

S to SAVE a song out to disk, complete with status field values.

W to WIPE a single track clear of all data. Confirmation is requested before the data is erased, to guard against accidental loss.

P to PLAY a song over MIDI. Data from all enabled tracks will be transmitted over the specified MIDI channels to the synthesiser.

R to RECORD data coming in from the synthesiser via the MIDI interface. If the Metronome is enabled there will be an eight beat lead in before recording starts. This gives you advance warning of the tempo of the song plus a consistent countdown to the point where you start playing the synthesiser.

T to allow you to RETIME the notes already recorded on the current track by tapping out the rhythm on any key. Otherwise it functions in the same way as RECORD.

Using the Sequencer for Playback

The easiest way to get started is to load and play the sample songs provided with MIDI Master. Follow the steps below to do this:

Ensure your synthesiser and computer are correctly connected with the MIDI Master cable as described above.

Ensure your synthesiser is switched on and it is set for multitimbral operation, i.e. that it can play several different instrumental voices simultaneously. Each synthesiser has its own way of doing this - on the Yamaha PSS machines you press the MIDI Mode button and then the + button under the I.e.d. display, which should then show a value of 99.

Ensure the Sequencer is loaded as described above.

Loading a Song File

Press L to load a file, then key in D1:MINUET.SEQ and press Return. This sequencer song file will then load from disk into the sequencer. It's recorded on Tracks 1, 2, 3, and 4. However, most of the notes come from tracks 1 and 2. with 3 and 4 contributing odd notes of harmony at infrequent intervals. You can't deduce any of this by looking at the screen in its present state as all eight tracks are set to play on channel 1 and the MIDI program number is set to zero for every track.

Press P and after a few seconds the song will play using the voice currently set for channel 1 on your synthesiser. You'll probably notice all voices play with the same sound, so to make them different you'll have to request MIDI program changes as follows.

Changing the Sounds

Using the arrow keys move the cursor to the Track 2 PLY field and change it from 01 to 02 by keying in that value. Similarly change the Track 3 and 4 PLY fields to 03 and 04. You have now set the sequencer to transmit on four different MIDI channels. If you press P now the song will probably still sound the same, as you've still not asked for different program numbers. However, different synthesisers work in different ways, so you might hear different sounds at this point. Try it.

Move the cursor to the PGM field for Track 1 and change it from 000 to some other suitable value. Try a trumpet - this is PSS voice 15, so key 016 into the Track 1 PGM field. Press P to try it.

Now do the same for Tracks 2, 3, and 4, using different voices if you wish. Note that each different voice should use its own unique MIDI channel.

Transposing the Sound

If the solo line doesn't stand out enough try moving it up in pitch, i.e. transpose it up an octave. Move the cursor to the TRP field for Track 1 and key in 12 - as twelve semitones represents an octave. Press P to play, you should hear the trumpet playing an octave higher.

Move the cursor to the + sign in the TRP field and press the Space Bar. The +12 will change to -12, signifying you want to transpose the track down one octave. Press P to hear the difference.

Try changing the key in which the whole piece is played. It plays in B major as supplied, so change the TRP field for Tracks 1 to 4 to +1, then press P. It will now play in C major. Note that when changing the key of a piece you have to change every active track by the same amount. Otherwise you end up with a very strange sounding arrangement!

Repeating a Song

This song is very short, so to make it longer you can request it to be played several times Move the cursor to the REP field for Tracks 1 to 4 and key in 01 for each track in turn. Press P, and the song will play through once and then repeat once.

Interrupting Playback

You can interrupt the playback of a song by pressing the Option key, but doing so may result in "stuck" notes. This happens because the notes are started by a MIDI "Note On" message and the Option key may cause the sequencer to stop before it sends out the corresponding MIDI "Note Off" message which terminates the note. The action required to get rid of the resultant annoying continuous droning varies depending on the type of synthesiser you have. You may have to reset it, or power it off then on again. It can usually be stopped on the Yamaha PSS by briefly switching from MIDI mode 99 to 00 and back.

Saving a Song File

When you are happy with the voices you have chosen for a piece you can save the song to disk. Place a formatted disk in the disk drive, press S then key in D1:filename.SEQ and press the Return key. Filename is the standard Atari DOS file name of up to eight characters. The song file will then be saved to disk complete with all channel, program, and other status information you have provided. When you next load the file it will have these values already set, so you can play it straight away without having to make any further changes.

Unfortunately, the sequencer has no access to DOS facilities, so you can't get a directory listing, delete files, or format a new disk from within the program. Therefore make sure you have a few empty formatted disks available before you start a music session.

Another Sample Song File

Now try something a little more complicated. Press L to load another sequencer song file, and key in D1:BRANDEN.SEQ then hit Return. This file will take much longer than the previous one to load into memory as it's far bigger. It's a movement from one of Bach's Brandenburg Concertos and plays for about 4.5 minutes. The main parts are recorded on Tracks 1, 2, and 3. About 2.5 minutes into the piece Tracks 4, 5, and 6 provide additional material, but these seem to contain notes which "stick", which spoils the effect somewhat. Accordingly, it's probably best to ignore them by setting their PLY channels to zero for playback. Try setting Tracks 1,2, and 3 to three different channels and assign two different violins and a cello to them respectively. On playback it will sound like a string trio. Then experiment with your own selection of voices.

Using the Sequencer for Recording

The MIDI Master sequencer provides very basic recording facilities. Each track is monophonic, so can't record musical chords - it can only handle one note at a time. This is fine if you're a "one finger" keyboard player. However, you can record on multiple tracks in parallel if you need to handle more than this.

Clearing Tracks

To illustrate the principles involved let's build up a series of tracks each of which contains a simple monophonic melody line. First, we need to clear out anything that's already recorded on the tracks. To do this position the cursor on the Track 1 status line, then press W (for Wipe Track). Then press Y to confirm the action, and if there's anything on the track it will be wiped clean. You'll also see the Buffer value increment as the space occupied is freed up. Repeat this for Tracks 2 to 8. You'll then have a completely empty sequencer.

Then make sure all status values in each line are set to zero.

Setting the Metronome Speed

Next, set the metronome speed by pressing the < and/or > key until it has a value of 10. This results in a speed of about one beat per second. Turn the sound up on your monitor, as the metronome clicks will be heard via the monitor speaker.

Setting the Recording Track and MIDI Channel

Move the cursor to the Track 1 REC field and key in 01 to denote that we want to record MIDI data from MIDI channel 1 onto Track 1. Make sure your synthesiser is set to transmit on channel 1, otherwise nothing will be recorded. Also, ensure it's set to play from its keyboard rather than from a MIDI data stream - Yamaha PSS series instruments should be set to MIDI mode 00, otherwise you won't hear what you're playing.

Recording a Track Monophonically

Now press R to start recording. You'll be given an eight beat lead in count by the metronome after which the sequencer will start recording. Play a simple ascending scale, with each note on the metronome beat. Make sure you play the notes in a detached fashion, so you can clearly hear the start and end of each one. If you run the notes into each other you won't have a truly monophonic melody line and this will confuse the sequencer, which could result in notes being lost. When you've finished, press the Option key to stop the recording and set the REC field back to 00 so you don't destroy the track next time you record.

Move the cursor to the PLY field for Track 1 and change it to 01. This sets it to play back over MIDI channel 1. Then move the cursor to the PGM field for Track 1 and set this to the particular voice number you want to use.
Press P to play back the recording. You should hear the scale exactly as you played it, using the voice you selected.

Now repeat the last four steps, but this time use Track 2. Set its REC field to 02 and ensure your synthesiser is set to transmit on MIDI channel 2. Strictly speaking this isn't necessary as you can use any channel you like for recording. However, I prefer to align track and channel numbers to reduce the possibility of confusion. Next, press R to start recording, and after the usual count in you'll hear Track 1 start playing back. Play something different along with it, perhaps a simple descending scale. Whatever you play will be recorded on Track 2.
This time, set the Track 2 PLY field to 02, set its PGM field to a different value from Track 1, and switch your synthesiser into multitimbral mode. When you now press P to play you should hear the two tracks play back together, each with its own voice.

If you wish you can now go on to record other tracks. Remember to match the synthesiser's MIDI transmission channel with the each track's REC channel before recording, and also to set the REC channel for previously recorded tracks to 00 before recording a new track. If you forget, you'll lose the data on those tracks!

Polyphonic Recording

The recording method described above deals only with monophonic melody lines, i.e. "one finger" tunes. To record polyphonically, i.e. using chords - more than one note simultaneously - you have to use several tracks in parallel, with one track used for each note in the chord. For instance, to record a four note chord you'd have to set up four tracks to record on the same channel at the same time. Wipe all the tracks you've already recorded on, zero out all the non Zero track status fields and try the following:

Set up Track I and your synthesiser to record on channel I. Press R to record, and after the count in play three simultaneous notes on your synthesiser's keyboard. Stop the sequencer and play back what you recorded. You'll hear a single note, showing that the single track selected can only record one note at a time.

Now wipe Track 1 and then set up Tracks 1, 2, and 3 all to record on channel 1. Press R to record and play the same three note chord. If you now play back the three tracks you'll hear all three notes of the chord, one on each track. To prove it play each track back individually, and you'll hear each note separately.

You can obtain some interesting effects by giving each track its own playback channel and setting a different voice for each. You'll also be able to hear how the sequencer splits the simultaneous notes across the recording tracks. Don't be afraid to experiment - it's great fun.

Recording Drum Tracks

So far I've been unable to obtain a satisfactory recording from the Yamaha PSS-680's drum pads. However, if you record the drum rhythms required from the keyboard rather than the pads, and set the PLY channel for the track to 16, you'll find you can successfully record and play back a drum track.

You'll have to look in the PSS's instruction manual to find out which keys correspond to which drum sounds (or find out by trial and error). You can't hear the correct sounds when you record, as they can't be directly triggered from the keyboard. However, the correct MIDI data is sent to the sequencer, so will play back fine as long as you transmit it on channel 16 on playback.

If using a PSS instrument and you want to change the drum sound you can use the TRP (transpose) facility to move the rhythm notes up or down in pitch by the required amount. Remember this transposes ALL notes on the track though, so is probably only useful if you've recorded each individual drum sound on its own track, e.g. snare drum on Track 6, hi-hat on Track 7, kick drum on Track 8.

Looping and Delay Facilities

The sequencer's looping and delay facilities can be useful when used with drum tracks. You can record a fairly short, simple set of rhythms on a couple of tracks and then repeat them over and over so they play through the rest of the song. For instance, if your song is 64 bars long you could record a 2 bar bass drum and snare rhythm on two tracks and automatically repeat these a further 31 times by keying in 31 as the REP field value for the two drum tracks.

You can also generate some interesting rhythms by recording several drum tracks and have each repeat of each track delay by a different amount. This is achieved by setting a value in the track's GAP field. When played back together you'll hear the rhythms shift and change against each other. You can also shift the timing of one track relative to another by specifying a value in the track's LEAD field.

However, having said that, it appears that this facility doesn't work as it's supposed to. It only seems to work if you set the GAP and LEAD values to an integer number of hundreds, i.e. 100, 200, 300, etc, which gives delays of approximately 2, 3, 6 seconds. This reduces its usefulness somewhat! You can only really determine how useful it is to you by experimentation, so go ahead and try it with different values.

Retiming a Track

This is a rather strange facility. It allows you to take the notes on a given track and retime them to play in a different rhythm. The operation may be dependent on the synthesiser you're using, so you may have to experiment to make it work with your particular instrument. Look for a mode which disconnects the keyboard from the sound synthesis part of the instrument - it may be called Local Off mode, or something similar. The procedure described below works with the Yamaha PSS-680.

Wipe all tracks, set the metronome to 10, and record an ascending scale in time with the metronome.

Press T - the sequencer will put up a message saying "Retiming - use any key for beat". You now have to tap out the new rhythm you want the recorded notes to play in using any key on the synthesiser's keyboard. The recorded notes will play as you tap the rhythm, and the sequencer will stay in this mode until you have tapped the key once for every recorded note.

The procedure would only work on the PSS-680 when it was switched to MIDI Mode 99. This is normally used for multitimbral operation, but the mode also disconnects the keyboard from the sound generation circuitry. When you tap the key, you're hearing note pitches played by the sequencer, but in the rhythm tapped out by you from the keyboard! It feels very strange to do, but appears to work OK. It could be useful for retiming drums on a rhythm track.

Unexpected Problems

Sometimes the sequencer doesn't record things in the way you're expecting. I've already mentioned a number of actions you should take to ensure you record successfully, but I'll re-iterate them here together with a few extra hints and tips:

Ensure your computer and synthesiser are correctly connected together with the MIDI Master cable. The two DIN plugs are identical, so make sure they're plugged into the correct sockets on your synthesiser. It's quite easy to insert the MIDI IN plug into the MIDI OUT socket and vice-versa.

Remember to boot the MIDI Master disk without BASIC, i.e. hold down the Option key when switching on the computer to perform the boot up.

Don't forget to turn on your synthesiser before use! The ON indication on certain types of instrument is not that obvious.

When recording make sure you set the track REC field and the synthesiser's MIDI transmission channel to the same value. If they don't match you won't record anything.

When recording subsequent tracks, make sure you've set the REC field of previously recorded tracks to 00, otherwise you'll over-record or otherwise destroy what you've already recorded on them.

"Stuck" or "droning" notes can be a nuisance - they can be cleared on Yamaha PSS instruments by momentarily switching MIDI mode from 00 to 99 and hack (or vice-versa). Otherwise, you may have to turn the power off and on again. Other synthesisers may have their own procedures.

If notes seem to be missing from a track you've just recorded, it's probably because you played too smoothly. The notes have run into each other, forming a two note chord for a fraction of a second. The sequencer can't handle this, and may ignore the second note. Try recording the track again, but try to detach the notes a little more.

Sometimes, when using the sequencer with Yamaha PSS instruments, it doesn't accurately handle the recording of a new track while playing back one or more you've previously recorded. The problem may also exist with other makes of synthesiser. This sort of operation seems to stretch the sequencer code up to (and beyond?) its limits, and I've found no reliable way of getting it to work correctly every time It sometimes helps if you turn off some (or in extreme cases, ALL) of the previously recorded tracks while recording the new one. With all playback turned off you'll then only have the metronome beat to guide you. This makes the building up of a multi-track recording more difficult, but it usually does the trick in terms of getting an accurate recording.




The MIDI Master package contains two music players. These can be used to play music files produced by two very popular Atari 8-bit music composition and arrangement programs, namely Atari's own cartridge based Music Composer, and Advanced Music System written by Lee Actor.

The Music Composer cartridge is still available, but Advanced Music System (and its later development Advanced Music System II) are now very hard to find. However, there are many music files produced by these programs in the public domain, and Page 6 Publishing have a series of public domain disks full of such material.

These two programs were designed to allow you to compose and arrange music on the 8-bit machine, and are the forerunners of today's step-time MIDI sequencers as found on the Atari ST. A step-time sequencer is a program which allows you to enter music one note at a time, rather than playing it into the program in real time as you do with MIDI Master's sequencer. They were written well before the advent of MIDI, so only make use of the 8-bit's internal sound chip. This limits them to a maximum of four simultaneously sounding voices, the maximum available on that chip. Even so, it's possible to create some very pleasing musical performances using them. MIDI Master's player programs open up a whole new world of sound to these programs, by reading their customised music data, converting it to standard MIDI messages, and sending them out through the MIDI Master interface to attached MIDI equipped instruments. These will then play the music as from any other MIDI data stream.

Loading the Player Programs

Ensure your computer and synthesiser are correctly connected together with the MIDI Master interface cable.

Turn on your disk drive and insert the MIDI Master program disk. 

Hold down the computer's Option key and turn on the computer. This will boot up DOS without BASIC. The DOS menu will appear on the screen after a short while.

Press the L key then the Return key to select the Binary Load function. In response to the "Load from what file?" message, key in APLAY for the Advanced Music System player, or MPLAY for the Music Composer player. Then press the Return key. The appropriate program will then load from disk.

Playing Music Files

Both programs look and behave similarly. Each has a single operating screen showing four selectable options as follows:

SELECT MONO MODE - press S to toggle the player between Polyphonic mode and Monophonic mode. In Polyphonic mode the data for the original four Atari internal voices are supposedly transmitted on MIDI channels 1 to 4. In Monophonic mode it's all transmitted on MIDI channel 1. After pressing S the message will change to read Select Poly Mode. Actually, the term Polyphonic is a misnomer - the program's author really meant Multitimbral, as this mode of operation is really designed to allow you to play a different sounding voice on each of the four MIDI channels.

In practice, the program doesn't work as intended! The meanings of Monophonic and Polyphonic seem to have been reversed. When Select Mono Mode is displayed the players transmit everything on MIDI channel 1, and when Select Poly Mode appears it's actually transmitting on channels 1 to 4!

LOAD TUNE - press L to load a music file. The message "Enter Filename" will be displayed, to which you reply D1:filename.ext. Filename is the name of your file, while ext is the file extender - usually taking a value of MC for Music Composer files or AMS for Advanced Music System files. However, ext isn't mandatory - your files don't have to have an extender if you choose not to use one. If it's already present on a file on disk, you must use it though.

PLAY TUNE - press P to play the file currently loaded into memory.

TEMPO - press T to change the speed at which the music plays. In reply to the message "Enter Tempo" key in a numeric value between I and 99, then press the Return key. The larger the value is, the slower the music plays

Sample Songs.

The MIDI Master program disk contains two sample music files for  each program. These are JESU.MC and HENRY8.MC for the Music Composer player program, and PRELUDE1.AMS and PRELUDE2.AMS for the Advanced Music System version. Don't forget that when you load them into their appropriate player programs you have to prefix these names with D1: to indicate you want to load them from disk drive 1.

Note - if you're using a Yamaha PSS synthesiser, remember to switch it into MIDI mode 99 if you want to use the player's polyphonic (multitimbral) mode of operation. If you use mode 00 you'll find all four channels play with the same voice, i.e. the one displayed on the instrument's L.e.d.. display. You'll probably have to take similar action with other makes of synthesiser too.


These programs have some limitations which are partly due to the differences between the way MIDI handles notes and the way the Atari 8-bit computer handles them.

Firstly, the programs do not support velocity sensitive data, so can't reproduce differences in volume for different notes.

Secondly, some Advanced Music System users utilise the fact that the Atari 8-bit's sound generators run continuously until told to do otherwise. They can thus produce sound envelope effects by playing identical notes in rapid succession, but with differing volume values. The player programs translate this as a series of discrete notes played as rapid re-iterations, which can sound very strange.

Finally, because neither of the two music systems directly support enveloping to produce different sounds, the music player programs provide no way of inserting MIDI program change messages into the data stream. This means the music plays using the same sound throughout.

There are also some synthesiser dependent points to watch. As we've seen, the programs have no facilities for sending MIDI program change messages to the synthesiser, so the assigning of voices to channels has to be done from the synthesiser itself. This is easy with some instruments, such as the Yamaha YS-200 Others, such as those in the PSS series don't let you do this. The result is that if you operate the program in Polyphonic mode you can't easily assign voices to specific MIDI channels. You may find yourself stuck with the first four preset voices unless you can find some way round the restriction.




Most synthesisers have sets of factory defined sounds (known as presets) which can be accessed and played at the push of a button or via a MIDI Program Change message. If you tire of these, and your synthesiser has programmable voice patch facilities, you may want to construct some custom built sounds of your own.

Sounds are usually defined to a synthesiser's sound generation circuitry as a large number of parameters, each describing some particular characteristic of the sound. Mast synthesisers allow you to manipulate these parameters, thus altering the sound produced. A set of parameters defining a given sound is known as a voice patch, and the synthesiser normally has on-board memory designed to hold sets of patches, so that any one of a number of patches can be called into use at any time. The storage on some instruments is very limited though, for instance the Yamaha PSS series has memory for only five patches. You soon find yourself discarding patches in order to store and use new ones.

Patch parameters may usually be edited from the synthesiser's front panel, but this is often a tedious operation requiring much button pushing and squinting at the instrument's tiny l.e.d. or l.c.d.. display screens. It's often easier to use a computer program to do this, hence the voice patch editor. Editor programs also usually act as librarians, allowing you to save patches to disk for long term storage, and to load them back later from disk into the computer for subsequent downloading into the synthesiser.

Different makes of synthesiser use different methods of sound generation. As you'd expect, each method requires completely different parameters to define the sounds, which in turn means that patch editing software written for a particular synthesiser won't work with instruments from a different manufacturer. Indeed it often won't work with different models from the same manufacturer! However, there are now a few "generic" patch editors available, which are able to handle a whole range of synthesisers. The two voice patch editors supplied with MIDI Master are hardware specific, one being designed for the Casio CZI01, and the other for the Yamaha DXI00, although both will work with certain other models in those manufacturers' ranges.

I've made no attempt here to explain what all the different voice parameters are! You'll have to refer to your synthesiser's instruction manual for this information.

The Casio CZ Patch Editor

This program allows you to edit existing preset voices or create completely new ones on Casio CZ101, CZ230, CZI000, CZ3000, and CZ5000 instruments. This is particularly useful for owners of the CZ230, the voices of which can't be edited from the front panel, but only via MIDI. It effectively turns a non-programmable preset synthesiser into a fully programmable instrument. Once a voice patch has been created it can be stored on disk for safekeeping, and reloaded for use at any later time.

Loading Instructions

Ensure the computer and synthesiser are correctly connected via the MIDI Master cable as described earlier.

Switch on the synthesiser.

Switch on the disk drive and insert the MIDI Master program disk.

Hold down the computer's Option key and switch on the computer's power. This will boot up Atari DOS with BASIC disabled.

From the DOS menu screen key in L and press the Return key to select the DOS program load option. You will then be prompted to enter the name of the file containing the program.

Key in CZV and press the Return key. The CZ voice editor will now load.

Editing a CZ Voice Patch

Once the program has loaded, its main operating screen will appear. This will show all of the parameters required to define a voice on the CZ instruments, but in a slightly different arrangement to that normally used to show CZ patches when printed in magazines, patch books, etc.

If you examine the screen you'll see it's divided into two main blocks of parameters, entitled Line 1 and Line 2. Between them you'll see a two digit number, with arrows above and below it. This number will change as you select different preset voices on the synthesiser, and represents the current memory pointer.

When you press the Option key the editor will fetch the patch parameters corresponding to this preset voice number from the synthesiser, and then display them on the screen for you to examine and change as required.
To change a parameter simply move the cursor to the required parameter using the cursor (arrow) keys (without Control key).

For Line Select, Modulate, and Octave parameters pressing the Return key will cycle through all the possible values for those parameters.

Numbers may be keyed in directly for the other parameters. Note that if you want to change the sign of the Detune parameter from + to - or vice-versa you have to use the P and M keys. This is because the + and - symbols are also on the arrow keys, which are already in use. Also, the S and E keys may be used to place the Sustain and End markers into the sets of Envelope data.

You can initialise a parameter at any time by pressing the Escape key. This will produce the same effect as pressing the INIT button on the synthesiser.

Once you've edited the patch you should press the Select key. This will cause the patch data to be downloaded to the synthesiser's internal buffer where you can play it, write it to a memory location, or write it out to a CZ RAM cartridge.

Note for CZ230 users - this model has only four programmable patch memories, numbered 96 to 99. If the memory pointer is in the range 97 to 99 then pressing Select will cause the patch data to be written directly to the relevant memory. Otherwise it will be written to memory number 96. To hear your edited voice you therefore have to select a voice in the range 96 to 99 on the instrument.

Saving and Loading CZ Voice Patches

To save or load a patch, press the Start key. The screen will change to a prompt saying COMMAND: followed by a cursor. Then key in L or S for Load or Save as required. The word LOAD or SAVE will appear in the prompt. Then key D (for disk) followed by filename.ext, where filename is the usual DOS file name of up to eight characters, and ext is the file extender, which could be CZ for CZ patch files. Press the Return key to execute the command, and the file will be loaded or saved as requested. After loading a patch you can immediately inspect or modify it from the main screen. If you make a mistake, press the Escape key to get you back to the main screen at any time.

Sample CZ Voice Patches

There are five sample CZ voice patches supplied on the MIDI Master program disk. These arc FUZZYWAH.CZ, MEDIEVAL.CZ, SWEEPWAH.CZ, STRING.CZ, and ORCSTRNG.CZ.

Follow the instructions above and try loading each of these in turn to see what they sound like. Then try modifying them to make your own sounds. Remember to save on disk any good patches you create, so you can use them again in the future.

The Yamaha DX Patch Editor

This program allows you to upload voice data from Yamaha DX100, DX21, and DX27 synthesisers and edit the parameters from the computer screen. It may also work with other Yamaha four operator synthesisers such as the TX81Z, YS-100, and YS-200 instruments, but you could find that the differences are enough to affect the sound in various ways.

As well as supporting single voice upload, the program will also allow the bulk upload of the synthesiser's internal programmable memories for storage on disk. These may then be retrieved and bulk downloaded again when required.

This program differs from the CZ patch editor in that data is automatically uploaded and downloaded from or to the synthesiser every time you select a new preset voice on the synthesiser or change a parameter on the computer screen. This means you can hear any changes you made straight away by simply playing the synthesiser's keyboard. However, note that the changes are only transmitted to the synthesiser's internal buffer. To store them permanently in the synthesiser's memory you have to follow the instrument's normal store voice procedure. If you don't do this, the next preset you select on the synthesiser will overwrite the buffer and you'll lose your patch.

Loading Instructions

Ensure the computer and synthesiser are correctly connected via the MIDI Master cable as described earlier.
Switch on the synthesiser.

Switch on the disk drive and insert the MIDI Master program disk.

Hold down the computer's Option key and switch on the computer's power. This will boot up Atari DOS with BASIC disabled.

From the DOS menu screen key in L and press the Return key to select the DOS program load option. You will then be prompted to enter the name of the file containing the program.

Key in DXV and press the Return key. The DX voice editor will now load.

Editing a DX Voice Patch

Once the program has loaded, its main operating screen will appear. At the top you'll see the program option in effect. On loading this will say Voice Editor. If you press the Option or Select key you'll cycle through all the options the program offers. When you see the option you want to use displayed, press the Start key. The available options are as follows:

Voice Editor - to edit voice patch parameters.

Load Voice - to load a single voice patch from disk. Save Voice - to save a single voice patch to disk.

Load Bulk Voices - to load a whole set of DX voices patches from disk and download them into the instrument's patch memories.

Save Bulk Voices - to upload a whole set of DX voices from the instrument's patch memories and save them out to disk.

The rest of the screen area contains the set of DX voice patch parameters, with one parameter on each line of the screen. There are more parameters than will fit on one screen, so a scrolling system is used to reach the ones initially out of view. Use the cursor (arrow) keys to move to the line containing the parameter you want to change. There's no need to use the Control key with the cursor keys, just use them on their own. The currently selected line will be shown highlighted. If you try to move the cursor off the top or bottom of the screen, it will automatically scroll to reveal the other parameters. To change a highlighted parameter, press the Start key. The new value for the parameter may then be keyed in.

I tried using the program with a Yamaha YS-200, which uses a four operator FM synthesis system similar to that in the DX100. I found I had to initiate both single voice and bulk voice upload from the synthesiser rather than the program. Voice parameters appeared on the editor screen OK, but making the simplest change to any parameter sometimes seemed to cause a big change in the sound.

Also, uploaded voices sometimes sounded different after being saved to disk then reloaded. There could be several reasons for this - firstly, there may be something about the YS-200 which makes it not quite compatible with the DX100/2l/27 instruments. Secondly, the YS-200 has a built-in effects processor which can have a dramatic effect on the sound, and the settings of this don't get saved as part of the patch. Thirdly, the program uses only unsigned numeric integers for parameters, and this could cause problems, as certain parameters seem to need fractional and/or negative values in some cases.

Saving and Loading DX Voice Patches

When selecting any option other than Voice Editor you'll be prompted for a filename. This has to be entered in the form D1:filename.ext, where the D1: indicates the disk drive, filename is the usual Atari DOS eight character file name, and ext is the file extender - you could use DX for DX voice patches.

There's just one sample DX voice patch supplied on the MIDI Master program disk. This is called WICKED.DX. To load it, follow the instructions above to activate the program, then repeatedly press the Option or Select key until the Load Voice option is displayed. Press the Start key, and at the prompt key in D1:WICKED.DX followed by the Return key. The voice patch should then load from disk. When loaded it will be automatically downloaded to the synthesiser also, so you should be able to play and hear it straight away.

Now try modifying it to make your own sounds. Remember to save on disk any good patches you create, so you can use them again in the future. To do this use the Select or Option keys to get the Save Voice option on the screen, then press the Start key. At the prompt, key in the File name in the form D1:filename.ext followed by a press of the Return key, and the patch will be saved to disk.

Bulk Voices

When requesting a bulk voice upload on a YS-200, only the first 32 voices from the programmable memories were transferred, instead of the complete set of 100. Again, this is caused by differences in the design of the YS-200 when compared to DX instruments. The same applies to a bulk voice download.

So, if you're using anything other than the three instruments the program was really designed for, you may not get the results you expect. However, if you can construct a voice you like using the editor, you should find you can then save it, reload it, and still get the same sound. This is because the voice is then defined within the limitations of the program. OK, it's not ideal - but then this is a very simple program! You should still get lots of fun from it though, even with all its limitations.



The software for Midimaster has now been upgraded so that many of the previous 'untidy' aspects have now been cleared up. Please read these instructions in conjunction with the manual.


Occasionally the cables are not marked, or are marked incorrectly, so that it is not possible to determine which is the Midi In and which is Midi Out. You will cause no harm to your synth by connecting the cables incorrectly. We suggest that you initially load a song from the disk, following the instructions in the manual, and try to play it. If no sound comes from the synth then change the cables round while the music is playing and the problem should be solved. Note that some synths need to be switched into Midi mode from the keyboard.


The Midimaster disk now boots up directly to the Sequencer. Just insert the disk in your drive and switch on the computer while holding the OPTION key. If you wish to exit from the Sequencer to DOS just press X at any time.


It is no longer necessary to specify the device (i.e. D:) so you may now just use a filename. You must, however, still use the correct extender (e.g..SEQ).

If an incorrect filename is used then the program will indicate the error in standard Atari format and the error will remain on screen for several seconds. Afterwards just press the L or S key and try again.


Disk Directory - Pressing D will search the disk for all files ending in SEQ

Delete File - Press E and you will be prompted for a filename to delete. Enter the filename in full and press RETURN

Format Disk- Press F and the message 'Format Disk in Drive 1 (YIN)' appears. Pressing Y will format the disk in Drive 1, any other key will abort. Note that this option only formats in single density.

Our thanks go to Phil Cardwell for the above improvements to Midimaster

March 1991