Cheetah MIDI Interface

MIDI INTERFACE

For ZX Spectrum 48k/128k/+2



INSTRUCTION MANUAL



Cheetah Marketing





Thank you for choosing the CHEETAH MIDI INTERFACE



The CHEETAH MIDI INTERFACE is an interface to allow the connection of

MIDI devices to a suitable computer, creating a powerful system with

many exciting capabilities.

To assure you that your MIDI INTERFACE will give you many years of

enjoyment, please be sure to read this owners manual carefully before

attempting to operate it.





FEATURES



8 Track Midi Sequencer

Controls any Midi compatible instrument

Records Velocity Data

Midi In Out Through

Real Time input

Step Time input

Forward and Reverse sequence playback

Transpose facility

Midi Delay

Fully menu driven software

Suitable for home or professional use





EQUIPMENT REQUIRED



MIDI INSTRUMENT(S)

CHEETAH MIDI INTERFACE (Supplied)

MIDI LEAD (Supplied)

ADDITIONAL MIDI LEAD (if required)





CONTENTS



INTRODUCTION

SET UP INSTRUCTIONS

THE MAIN MENU

RECORD A VERSE

TRACK AND VERSE TO RECORD

ADJUST A VERSE LENGTH

LINK TWO, OR COPY ONE VERSE

DELETE A VERSE

REVERSE A VERSE

TRANSPOSE FOR KEY SHIFT

DEFINE SEQUENCE TRACKS

TRACK ENABLE SWITCHES

EDIT FACILITY

STEPTIME EDITING

SONG EDITING

PLAYBACK OR DELAY

PLAY THE SONG

ADJUST THE METRONOME

ASSIGN CHANNELS TO TRACKS

CHANGE INPUT CHANNEL

SET INPUT OPTIONS

SET OUTPUT OPTIONS

SYNCHRONISATION

SAVE AND LOAD SEQUENCE DATA

SERVICE INFORMATION





THE CHEETAH MIDI RECORDING SYSTEM



INTRODUCTION



MIDI is an acronym for Musical Instrument Digital Interface, the high

speed communications system used by synthesisers, sequencers and other

music hardware. The main function of the MIDI system is to allow one

instrument to send information about which note is being played to on

or more other instruments.

IN most small MIDI systems there will be only one 'information

provider', (usually a synth), which will send note information to one

or more instruments. They will be used as a 'realtime' system where a

musician can control more than one sound from a single keyboard.

Traditionally, music has been recorded on magnetic tape as sound to be

played back at a later time. This, while satisfactory, does not allow a

musician to change a track's sound (from a flute to a xylophone for

instance) without re-recording.

The advent of computers has changed the professional music industry

by allowing a record producer to store the music as a list of

information held in a computer's memory. For example, the

representation below shows two instruments playing ascending and

descending notes on two separate tracks.



beat track 1 track 2



1 note on, pitch c, octave 1 note on, pitch c, octave 2

2 note off, pitch c, octave 1 note off, pitch c, octave 2

3 note on, pitch d, octave 1 note on, pitch b, octave 1

4 note off, pitch d, octave 1 note off, pitch b, octave 1

5 note on, pitch e, octave 1 note on, pitch a, octave 1

6 note off, pitch e, octave 1 note off, pitch a, octave 1



Track one was originally played on an electronic piano and track two

on a string synth, but rather than being recorded as sound, the two

tracks were recorded as notes in the computer and could be played back

as a synthesised 'slap bass' and a drum beat if required.

Until recently this was only available to a recording studio with

thousands of pounds to spend, but now you can do all that with the

Cheetah MIDI Recording System.

The system will allow you to record up to 8 tracks of music, each

track having 16 verses stored in it, each verse being from 1 to 64 bars

in length. Each track may be assigned to any one of sixteen music

channels and a song constructed and played on any or all of the 8

tracks simultaneously. In addition to this, all of the information may

be stored onto a tape or other storage device.





SET UP INSTRUCTIONS



Turn the computer off. Connect the MIDI Interface to the rear of the

computer. Do not force the connector too hard. Connect the MIDI IN

socket to the OUT socket of your master controller, the MIDI OUT socket

to the IN socket on the slave device. Optionally connect the MIDI

THROUGH socket to any slave device that you do not want to send

sequenced information to. (If you have only one synthesizer connect OUT

to IN and IN to OUT on both devices).





+-------------------------+

| +-------------------+ | .................

| | V | : :

| | +-+--+----+-+ :

| | |IN OUT THRU| :

V | | | V

+-----------+--+-------+ +----+-----------++ +-------+--------------+

| IN OUT | | | | IN OUT |

|+--------------------+| |+++++++++++++++++| |+--------------------+|

||OO|OOO|OO|OOO|OO|OOO|| | +++++++++++++++ | ||OO|OOO|OO|OOO|OO|OOO||

|||||||||||||||||||||||| | +++++++++++++ | ||||||||||||||||||||||||

+----------------------+ +-----------------+ +----------------------+



MASTER CONTROLLER COMPUTER SECOND INSTRUMENT

(Main Keyboard of Synth.) (OPTIONAL)





Switch the computer on. Rewind the tape fully on side 1. Type "LOAD"

and press ENTER. Play the tape. The tape will load one picture and two

blocks of program and you will be asked to stop the tape. You may

choose to transfer the program to microdrive or begin. If you choose to

transfer to microdrive you will be asked to play the tape again. DO NOT

REWIND TO DO THIS. The automatic run program is stored on the tape

AFTER the main program.





THE MAIN MENU



All of the options on the Main Menu may be selected by using the up and

down arrows to highlight the option which may then be accessed by

pressing enter.





RECORD A VERSE



You will be shown a visual metronome which moves in time to the tempo,

the value of that tempo in beats per minute and the present

quantization value. In addition to this an audible metronome will be

played on the beeper or through your television set. The beat is

variable during recording by using the up and down arrow keys between

40 and 244 beats per minute. The quantization is also variable by using

the left and right arrow keys to increase and decrease the level

between 0 and 9. Quantization is a process which automatically moves

the beginnings and ends of notes to fixed positions in the bar. For

example, with the quantise set to 9 any notes played or released will

be moved to the nearest half beat, automatically tidying the bar. This

is fully variable while recording and you may alter the quantise and

listen to its effect before merging the bar.



The quantisation values are:



0 no quantise 5 1/8 triplet

1 1/32 triplet 6 1/8 note

2 1/32 note 7 1/4 triplet

3 1/16 triplet 8 1/4 note

4 1/16 note 9 1/2 note



When you start the record run you will see a magenta border, the

metronomes will run and you will be given two bars lead in. On the last

beat of the second bar the border will flash yellow and a loud beep

sound to tell you to get ready. On the next beat the recording starts,

the border changes to red and any notes you play will be stored. After

the correct number of bars the border will again become magenta and the

process will start again. There is no limit to the number of times you

can repeat this cycle and notes played will be 'layered' onto those

played previously. To stop recording press the spacebar. If the border

is red when you do this you will be asked to wait while the record run

completes itself.

You may then:

RESTART the record run and continue the layering process, MERGE the

recorded verse with the permanent memory (this will simply save the

verse if it is a 'first time run' or layer the verse onto any previous

recordings), APPEND the recording to the current verse (add it on the

end), TRANSPOSE UP or TRANSPOSE DOWN by one semitone. (To try this

record a verse with only one note it, press space, select append, then

transpose up, append, transpose up, append, quit and select play a

sequence), QUIT without keeping the verse.

If your record run fills the memory up, a warble note will sound and

the border will flash yellow (time to start deleting unwanted verses).



WARNING... When a record run starts the computer tidies the memory

beforehand. Sometimes if the verse you want to record has a lot

keypresses or control wheel information in it, the metronomes do not

start straight away. Be patient it may take some time for the poor old

Z80 processor to do all of the work.





TRACK AND VERSE TO RECORD



Each track has sixteen verses labelled A to P. Use the up and down

arrow keys to select the verse you want to work on. Enter returns you

to Main Menu.





ADJUST A VERSE LENGTH



Any or all of the verses may be as long as 64 bars, (for orchestrated

symphonies etc). The only limiting factor is the amount of keypresses

the memory can store. When the program is first loaded, a Verse is four

bars long. To vary the Verse length, use the up and down arrow keys to

increase or decrease the number of bars in the Verse. Enter stores the

required number of bars and returns you to the Main Menu.





LINK TWO, OR COPY ONE VERSE



Select this option to link together (append) two Verses into one, or

copy one Verse.

If you copy a Verse to an empty Verse, then a duplicate of the

original will be formed in the new Verse.

If you append a Verse to another Verse, then the destination Verse

will have the source Verse added to it. You could append one Verse to

the same Verse, giving a Verse twice as long as before. Note however

that this will lengthen the original permanently. Copying the original

to an empty Verse before appending it to itself would avoid this.

When you have entered the source Verse, you will be returned to the

Main Menu. If you entered an empty Verse as the source Verse however,

you will be given an error Message and returned to the Main Menu.





DELETE A VERSE



Will remove the Verse specified, to leave more room in memory.

Enter the Verse to be deleted. You will be asked to confirm your

choice, to avoid deleting any wanted Verses. Confirming your choice

deletes the chosen Verse and returns you to the Main Menu.





REVERSE A VERSE



Turns a bar of music backwards.

Enter the Verse to be reversed. Once you have entered the number and

letter of the chosen Verse, it will be reversed and you will be

returned to the Main Menu. Q will exit if selected by mistake.





TRANSPOSE FOR KEY SHIFT



Select this option to directly transpose a Verse by up to 12 semitones

in one operation. Enter the Verse number and letter and then use up and

down arrow keys to transpose the Verse by up to 12 semitones higher or

lower than the original pitch. Enter carries out the operation and

returns you to the Main Menu.





DEFINE SEQUENCE TRACKS



When recording you are able to hear any Verses specified from this

option as backing. Also if you wish to, you may record a repetitive

sequence to loop continuously from the 'play a sequence' option. In

this way it is possible to have a number of 64 bar backing sequences

stored for playback in a live set for example. To select the track,

press the track number and use the up and down arrow keys to select

Verses A-P. Enter returns you to the Main Menu.





TRACK ENABLE SWITCHES



If a song or sequence track is not needed you may turn it off rather

than delete it. This is also useful while recording to switch out any

distracting music. To toggle a track on or off press its identifying

number. Enter returns you to the Main Menu.





EDIT FACILITY



Here you may edit a Verse in steptime or a song page with up to 30

verses per track. Select the desired edit mode.





STEPTIME EDITING



The Verse is displayed in 'pianola' fashion from left to right. The

beats are marked on the bar as single lines, bars start with a double

line. The beat and bar markers are taken from the current time

signature.

When a note is playing in any one time slot, a black bar will be

displayed.

Only one octave is displayed at a time, but you have a reference in

the form of an 11 octave keyboard at the bottom of the screen. On this

a red flashing bar denotes the current octave.

To select a particular pitch you may use the up and down keys, or

play the note from the keyboard after selecting (N)ote. In all cases,

the octave and pitch will be displayed and a bright bar placed across

the screen. This bright bar is the pitch cursor.

To select the chronological position, the left and right keys move by

one beat in the current signature, (F)orwards and (B)ackwards by one

bar, with Z and X to move a fine cursor 'space invader' style.

You can (I)nsert a note between two end points. Move to the pitch

position, Select I, mark one end with the cursor by using < > F, B, Z

or X, then press SPACE. Select the other end in a similar way, press

SPACE again and the note will appear.

You may move (M)ove one or other note end to a different place. Put

the pitch and time cursors over the note to be moved, select M and then

select (E)nd or (S)tart. Move to the new end point and press SPACE. The

note end will be shifted to a new place (don't worry if the note

disappears momentarily). NOTE... if you move a start to a place after

the note end, or an end before a start the note will be erased.

Be careful not to (I)nsert of (M)ove on top of the other notes as a

housekeeping process removes any unnecessary notes and you cannot play

the same key twice at the same time.

Deleting is done by pointing to the note with both cursors and

selecting D.

When editing is completed to your satisfaction quit, with Q.





SONG EDITING



Songs are generally made up of sections: Introduction, 1st Verse, 2nd

Verse, Chorus, 3rd Verse, etc., etc. When these individual sections are

joined together, a song is formed. In the program, we call each of

these sections Verses and give them different letters to tell them

apart. Thus, Verse A would be the introduction, Verse B would be the

1st Verse, Verse C would be the 2nd Verse and Verse D would be the

chorus etc., etc.

Each of the eight tracks available in the program may have up to

thirty separate Verses. Each of these Verses may have up to 64 bars in

length.

On any track you may specitfy a sequence of verses to be played. Each

verse will be played on the correct channel until its end. Then any

space in the song sequence will stop all activity on that track.

For example, to play on track 1, two verse 'A's, one verse 'C'

followed by three verse 'D's, simply edit track one for: AACDDD

and select 'Play the song'. If you need to put time in with no music

just record a bar and don't press any keys.

To edit the verse letters into position use the cursor keys for

movement and enter the verses by letter. To erase a letter, use the

spacebar. To exit press ENTER.





PLAYBACK OR DELAY



Selecting PLAY A SEQUENCE will repeatedly play the sequence tracks.

To finish playing the sequence loop, press the spacebar. A new menu

will give you the following options:

CONTINUE will restart the loop from wherever you stopped it,

RESTART begins the loop afresh,

QUIT returns to the main menu.

Selecting Delay will give you a MIDI echo. Adjustable in 0.1 second

steps, this echo will re-transmit anything on the MIDI IN line to the

MIDI OUT line after the specified delay. The maximum length of delay

varies according to the amount of Note memory free.





PLAY THE SONG



Sends verses from the appropriate tracks, to the channel specified, in

the order listed on the 'edit song' page.

When selected you will see a new menu with these options, BEGIN, PLAY

NOW, starts the song, EXTERNAL START, waits for a 'start song' command

from the jmidi system or for the run/stop line to go high if you are

using an external sync option, PLAY FROM HERE, continues from the point

where the song was stopped, MAIN MENU, to exit.

To stop playing at any point, press space as for the play sequence

option. The play song menu will be displayed again.





ADJUST THE METRONOME



When recording or playing, a metronome system is provided to help you

to keep in tempo. This metronome defaults to 4:4 time but may be

adjusted to suit the type of music you want to record.

You can hear the metronome beats through the beeper or via the

television speaker and see a visual representation in any of the record

or play windows. To adjust the timing you must decide upon the number

of beats in the bar (numerator) and the number of beats per full note

(denominator). For example, 4:4 time has 4 beats in the bar and each

beat is a quarter note long (4 beats per note), 9:2 time would have 9

beat markers in the bar and each beat would be half a note long. This

can be seen when you steptime edit. The pianola type display has the

current timing superimposed with the note information.

The metronome has no effect on the way that a piece of music is

recorded or played. It is only there to help you to keep time and may

be changed at any stage.

To adjust, select (N)umerator or (D)enominator, then use the up and

down arrow keys, ENTER finishes and stores the selected signature.





ASSIGN CHANNELS TO TRACKS



Each of the eight tracks may be sent to any one of sixteen separate

MIDI channels and thereby to any one of sixteen different MIDI devices.

To select the track, press its identifying number, then use the up and

down keys to adjust the channel number. Enter will store the settings

and quit.





CHANGE INPUT CHANNEL



You may record from any MIDI channel, although in most cases you will

only have one information provider connected to the IN socket. If you

want to record from one channel and exclude information from all

others, you must set the input channel number to match the output

channel on the device you are recording from AND turn off the OMNI mode

with the input options menu. Use the up and down arrow keys to change

the MIDI channel number within the range 1-16. Enter.





SET INPUT OPTIONS



With this menu it is possible to 'filter' the information that you

record.

First check with the instruction manual of the chosen instrument, to

see what MIDI data is transmitted from it, as not all instruments can

transmit such function as key pressure etc. Turn off all the functions

not required to be received by the MIDI INTERFACE, as this will avoid

memory being reserved to record information not being sent. Each of the

eight functions may be switched on or off by pressing the number

corresponding to the required function to be switched. The functions

selected are highlighted in blue. Enter stores the required options and

returns you to the Main Menu.



1..Omni On when selected

allows recording from all MIDI channels regardless of the setting

of input channel.

2..Allow Program Changes

will enable you to record a patch change in the verse.

3..Record Pitch Wheel

allows you to store the pitch controller information in the bar.

The pitch wheel is capable of sending large amounts of information

which may 'clog up' a verse. If this is turned off is may help you

to save space.

4..Record Mod Wheel

as above.

5..Enable Continuous Controller

as above.

6..Allow Mode Changes

if selected this will enable you to record all of the MIDI mode

change information in the verse.

7..Poly Key Pressure

If your synthesizer has pressure sensing on every key it may be

recorded by using this option.

8..Channel Pressure

as above but not so expensive.



When you have selected all of the desired options press enter to store

them.





SET OUTPUT OPTIONS



This menu is used in the same way as the one above, the only difference

is in the first option.



1..Enable Running Status

will only transmit status bytes when a status change is required.

This means a potential time saving of 30% in MIDI transmission

time.





SYNCHRONISATION



The program runs its own internal clock synchronisation in most cases,

providing the timing for other instruments to play the note data being

sent. Use the menu displayed when this function is selected, to change

to an external MIDI clock, such as from a drum machine or other

sequencer. You may also synchronise with a sequencer using 96, 48 or 24

pulses per quarter note. In this instance pins 1 & 3 of the MIDI THRU

socker are used to receive clock pulses. Pin 1 will accept the Run Stop

signal and Pin 3 will accept the Clock.

Use the up and down keys to select and Enter returns you to the Main

Menu.





SAVE AND LOAD SEQUENCE DATA



You may save your recorded information plus the song page to either

tape or MICRODRIVE and retrieve it at a later time. HINT... save it

several times on different tapes or drives, in case your copying media

is suspect -- a lot of hard work can disappear into thin air.





PLAY IT AGAIN SAM!





(C) CHEETAH MARKETING LTD. 1987

Designed by Speedwell Software, I.O.W.







SERVICE INFORMATION



ONE YEAR GUARANTEE



Your new Cheetah product has been tested and inspected before leaving

the factory. It is guaranteed against defective materials or

workmanship for a period of one year from the original purchase date

provided it has been properly operated and maintained.

During the above guarantee period, any defects in parts or

workmanship will be repaired by Cheetah Marketing Limited at no charge,

except for a handling and return transportation charge of L1.50 which

must be enclosed when returning your unit for service. Make remittance

by cheque or postal order payable to Cheetah Marketing Limited. Do not

send cash or stamps. Return your unit postpaid to Cheetah Service

Department, (C.O.D. packages will not be accepted).

Please pack your unit carefully with proper wrapping to avoid

breakage as no liability can be accepted for damage of loss in transit.

To expedite processing, please ensure nature of failure is indicated.

At its option, Cheetah Marketing Limited, may elect to replace the

entire unit, rather than repair it. This guarantee does not cover

replacements of cases or screws.

This guarantee is void if the defect is due to use of the product for

other than the purpose it is designed for, or to accidental (whether in

transit or otherwise), misuse, neglect or repair other than by the

manufacturer.

Cheetah Marketing Limited disclaim any liability for incidental or

consequential damages.

This guarantee becomes effective only if a letter is completed and

mailed within ten days of purchase giving the following details:--

When and where purchased, with copy of receipt.

These statements in no way prejudice the statutory rights of the

purchaser.



This applies to UK only.



CHEETAH MARKETING LTD

Norbury House, Norbury Road,

Fairwater, Cardiff CF5 3AS.

Telephone: Cardiff (0222) 555525

Telex: 497455 Fax: (0222) 555527