HARDWARE

The rear panel of the 23 x 21.5 x 3.5cm ADAS unit sprouts a 14" multicore cable which plugs into the Atari's DMA port. To the left of the cable is a conventional DMA socket into which a hard drive should be plugged. Rear panel sockets for both DMA connections would be a more robust solution, but there simply isn't room. Space considerations also dictate the use of stereo quarter-inch jack sockets for analogue audio inputs, so a trip to Tandy for an adaptor (or some cable and solder) looks inevitable.

The remainder of the rear panel is taken up by two phonos (that provide digital I/O with an additional £359 S/PDIF interface card) and a multipin socket (for an external PSU). The ADAS front panel is a spartan affair, with just two ventilation grills and four LEDs labelled Power (on), Disk (access), Record (in progress) and Digital (I/O in use).

For nasty technical reasons, individual DMA cables must be less than 14" long. This isn't a problem for Mega ST owners, as the ADAS unit and hard drive can be stacked on top the Mega ST brain. However, if you have a 520/1040ST, the only solution is to make enough space for ADAS and hard drives to sit to the right of your computer.

SETTING UP

Most hard drives ship with disk formatting software, however due to a limitation in the Atari's GEM software hard disks larger than 250 megabytes cannot be formatted as one partition. To overcome this, the ADAS application includes a menu item called 'Extendidrive' that makes space above 250MB (megabytes) available to ADAS, though not to GEM. For this reason, files longer than 25 minutes, or files residing in the non-GEM area, will not be visible on the Atari desktop.

With large drives it's best to make a small partition so that ADAS (and all your other software) can be run direct from the hard disk. With a small capacity hard disk (40MB or less) it's best run both ADAS (and your MIDI sequencer) from the ST's floppy drive, leaving more room for audio, and reducing the effects of disk fragmentation. The ADAS Editor/CueSheet application (ADAS.PRG/ADAS.RSC) and desk accessory (ADAS.ACC) are not copy protected and can therefore be dragged onto your main sequencer application disk.

RECORDING

The ADAS main screen contains a vertical strip of 20 icons, with most functions duplicated in the File, Edit, Options and Windows menus. A cassette-like icon provides access to the Transport window from where a recording is setup. As with all tapeless systems, it's necessary to specify a file name, sample rate, and duration for the recording.

ADAS offers both 44.1 kHz and 48kHz sample rates, though the latter does not produce the appropriate increase in frequency response, since the ADAS anti-aliasing circuitry is optimised for 44.1 kHz. This exercise in cost cutting means that it's best to record at 44.1kHz, since 48kHz requires around 10% more space per stereo minute yet produces no tangible improvement in audio quality. 48kHz is provided purely to support the transfer of ADAS files to DAT players incapable of 44.1kHz digital recording (when using the optional S/PDIF interface card).

On clicking the Transport window Record button, ADAS checks the hard disk, displaying a warning message if there is insufficient space, though without actually revealing how much recording time is available. If all is well in the space department, audio at the ADAS input is routed through to the ADAS output, and a dialogue box appears bearing the legend "Press OK To Start Sampling". At this stage you can monitor the recording level by accessing the Meters window. ADAS provides no way to alter the recording level, so you have to make alterations at source. On pressing OK, the ADAS Disk and Record LEDs illuminate, and the hard drive whirrs into a frenzy of activity.

Recordings can be checked using the Transport window controls, the counter displaying the current location in hours: minutes:seconds:frames, ie. timecode format. The transport window also has fields for setting up punch in and out times. However, as it's impossible to hear audio up to or after the punch in/out points, the feature is musically redundant, though it may be of some use to those willing to take their cue from the transport window counter.

ADAS recordings cannot synchronise to incoming MIDI Timecode (which would require external control of the ADAS sample rate), but an 'MTC Time Stamp' can be recorded along with audio by ticking a field in the Transport window. This allows files in the CueSheet to be triggered from MTC, as we'll see later.

EDITING

Editing can begin once a recording is opened from the file menu, whereupon its contents are displayed as two amplitude envelope displays (representing left and right channels) in an Edit window (see Edit window screenshot). As Atari file names are restricted to eight letters, the top of the Edit window provides a field in which you can add a further 10 letters of description. ADAS automatically inserts the word "whole" in parenthesis for a newly recorded file.

When first opened, the entire Edit window is displayed in inverse video, indicating that the whole file is 'selected'. Clicking the loudspeaker icon therefore plays all the file, a marker indicating the current playback position by moving (rather jerkily) across the Edit window. You can stop playback at any point by pressing both shift keys simultaneously. A single key — preferably the space bar — would have been less awkward.

A smaller part of the file can be selected for playback by clicking and dragging the cursor within the edit window, the lower row of tiny numbers at the top of the window indicating the selected area start/end times. As ADAS offers no Cut and Paste commands, editing involves selecting the desired start and end points and "Save(ing) The Marked Area" (using the scissors icon) as a new file ready for insertion into a CueSheet. Thus the CueSheet can play bits of a song in a different order or, with enough disk space, multiple tracks can be compiled into a new running order.

A marked area saved under a new name is referred to as a 'seg'(ment). Segments are not audio data, but simply files instructing ADAS to access an original (whole) file, and play from sample x to sample y, thus they occupy hardly any disk space. Segment files also permit non-destructive editing since the original file is left untouched. Saving a marked area under its original filename will replace the original with the segment, but this is ADAS's way of providing 'topping' and 'tailing' — editing space from the start and end of a file to recover valuable recording time.

To aid the location of start and end points, ADAS offers 10 markers (that can be entered on the fly), and a very primitive form of audio scrubbing. It works by repeating 0.25 of a second of audio around the current position of the edit point when the mouse button is held down. As such, ADAS scrubbing is not a precise tool, but an audio aid to assist in finding the general area of interest.

Having located a rough position, the 'Zoom In On Marker 1' command (accessed from the magnifying glass icon labelled M1) doubles the display resolution, and rather cleverly centres the start point in the middle of the Edit window. (A 'Zoom In On Marker 2' end point command is also provided, labelled M2). Subsequent Zoom Ins continue to double the resolution up to sample accuracy.

Zoom Out versions of M1 and M2 would be a good idea, and could replace the standard 'Zoom In/Out X Axis' commands which are essentially redundant. 'Zoom In/Out On Y Axis' commands are also provided, and are useful for examining quieter passages. Zooms take around two seconds to re-draw the waveform, but you can turn the waveform display ('Waveform Edit') off and view a simple black strip ('Tape Edit'), in which case zooming is instantaneous.

As the Edit window Zooms, the current magnification ratio is displayed in the top right hand corner of the Edit window, while the top row of tiny numbers display the file start and end times of the current view — in other words the length of audio in the edit window. The numbers are tiny, and large amplitude waveforms actually obscure them. Auto-calibrating scaled axes would have been an easier solution.

A unique and very useful ADAS Edit facility is the ability to swiftly and accurately divide a song into its constituent parts — say Intro, Verse, Chorus, Bridge etc. — ready for rearrangement in the CueSheet. Having found the start and end points of the Intro and 'Saved Marked Area', you can turn the end marker into the start marker for the next segment by holding down the shift key while moving the cursor in the edit window. Having saved segments for the entire song, each can be added into the CueSheet, and as the end point of one segment becomes the start time of the next, the join is sample accurate and therefore perfect.

CUESHEET

The ADAS CueSheet window fills the entire screen and contains its own scrollable window into which up to 128 files and/or segments (entries) can be added (see CueSheet screen dump). Clicking the Entry Open button accesses a standard file dialogue box, and when you select the desired file, a second 'Add' box appears giving the file's full name, length and start time, plus various timing, insertion and panning possibilities.

By default, CueSheet entries follow on from each other making it very swift and easy to build up a CueSheet with no gaps. However, as the CueSheet can read MTC (by clicking the clock source field), provision is made to insert a file using its MTC time stamp or even by typing in a new time code address (in the Add box).

Under MTC control, and assuming you have a SMPTE/MTC synchroniser, entries in the CueSheet are 'triggered' at their respective time code addresses. However, as there is no control of the ADAS sample rate, the CueSheet cannot be said to be truly in sync. However, for adding sound effects to video, all is well provided that files are less than a minute long.

The CueSheet MTC trigger facility is, however, made somewhat less useful by ADAS' inability to treat left and right channels independently — you must make and play back recordings in stereo. In terms of sound effects, this means that you cannot use two separate mono files, so overlapping sound effects must be added in separate passes.

The Add box also allows values for left and right volume to be entered. By setting them to different values, you can pan a recording. Playback from any part of the CueSheet can be made by clicking on a particular entry before pressing Play, which is handy. Another useful facility is that if you change the CueSheet Start Mode from File to Absolute, you can check splice points by typing in a time value close to the end of one entry and the beginning of the next.

If a splice doesn't work, there are no facilities to edit the segment within the CueSheet, so it's necessary to return to the Editor, open the file and edit the start and end points in the usual way. As there's no way to 'nudge' the start or end points in tiny (user definable ) increments, fine tuning takes a lot of work.

If a splice works musically and rhythmically but still glitches, it cannot be improved by crossfading techniques since the ADAS crossfade time is fixed at 0.25 milliseconds. Other systems use computer RAM to increase crossfade times, but ADAS steers clear of using Atari RAM to ensure that the ADAS application will run on the lowly 520ST. In practice this means that the CueSheet is fine for editing rhythm based songs such as dance tracks, but splicing together lots of fiddly bits, or a song based on an acoustic instrument is almost impossible. However, Plasmec are considering an upgrade option that will allow ADAS to use the Atari's RAM for crossfades and other purposes.

For those with hard disks large enough to store an album's worth of music (450MB = 45 minutes), the ADAS CueSheet can be used to assemble a running order. For this task, the ability to insert a CueSheet entry at a specific time is useful to determine the gap between tracks. Checking how the tracks segue is fast and simple thanks to Absolute mode.

If you are lucky enough to own a DAT machine, it's possible to keep everything in the digital domain by installing the ADAS S/PDIF interface (a simple open the case and plug in job). However, it's important to ensure that all tracks have the same sample rate, otherwise some will transpose in pitch. (On the other hand, the Enos of this world will probably exploit this limitation to good effect!) Any CueSheet can be saved, so you can make several different edits or compilations from the same song(s). As with the Editor, you stop playback by pressing both shift keys simultaneously.

MIDI CONTROLLED RECORDING

The ADAS desk accessory allows up to 36 files to be triggered (into record or playback) from a MIDI note number derived from Notator/Creator, Cubase/Cubeat or Virtuoso MIDI sequencers. The way each sequencer addresses ADAS is slightly different, but in each case it's essentially as simple as assigning a track to ADAS instead of a MIDI port. Cubase/Cubeat requires a driver that should be inserted in the M.ROS folder. ADAS support is built in to the latest versions of Notator/Creator and Virtuoso.

Unfortunately, you can't simply go straight into record and start singing or playing; there's rather a lot of setting up to do. Firstly you have to decide whether you intend to play or sing an entire song, or record a line (or a verse etc.) at a time. In either case, you have to record a file of appropriate length from the ADAS Editor application first.

The next stage is to insert a Note On Event (of equal length to the ADAS file) on a sequencer track at the point you wish to record, remembering to programme a track delay of -75 in Cubase/Cubeat and -40 in Creator/Notator (no value was supplied for Virtuoso). The delay is necessary so that ADAS has time to prepare the hard disk.

The final preparatory stage is to open the ADAS desk accessory and choose the file you wish to record into, and set the MIDI channel and note number to which ADAS should respond. Six files can be 'primed' in any one 'control card', with six additional cards available by inserting a MIDI program change into a track. The card system is required to limit ADAS's use of Atari RAM, so as not to deny 520ST owners the pleasure of MIDI controlled recording. (The RAM is required in order to provide a 'buffer' to ensure instant playback when a note on is received. Each card requires 200K of RAM, so 36 files, in six primed cards, would require 1.2MB).

It's important to remember the names given to the files prepared in the ADAS Editor application, since the desk accessory does not offer the standard GEM file selection dialogue box. Instead, it's necessary to type in a file name using the DOS convention, eg. "C:\audio\vocal.trk". In English that means "I want the file 'Vocal.trk' which is in the folder called 'Audio' on drive C." Having filled in the MIDI channel and note number boxes, set the file status to record, and selected analogue or digital ADAS input, you can close the desk accessory and, yes, you can finally make a recording by clicking your sequencer's record or play button.

Having made a fluff-free recording, it's necessary to set the ADAS file back into Play mode before pressing the sequencer's playback control, otherwise your perfect take will be overwritten. It's also important to remember that the audio recording will only remain 'in sync' with MIDI data as long as the tempo stays fixed at the tempo at which it was originally recorded.

Though ADAS is a 2-channel stereo device, you cannot record left and right channels independently. This means that though you have two channels, you cannot record (say) a vocal and a guitar part in separate passes — it's either or both. Still, limitation breeds creativity right?

Should you run out of recording time, it's possible to create a little more by topping and tailing files in the ADAS Editor application. If you prepared multiple ADAS files to record a performance phrase by phrase, it's unlikely that much time will be recovered in this way. However, if your performance was recorded in one or two takes, you could split it into lines or riffs and save plenty of recording time, though it would then be necessary to insert new notes on the ADAS track.

So there you have it — MIDI controlled hard disk recording on the Atari. It takes a fair amount of setting up, but it works, and if you already own a hard drive it's only £839. Depending on the interest that ADAS generates, Steinberg, C-Lab et al may be willing to integrate ADAS into their sequencers more fully. C-Lab began work on an Atari Sound Tools version of Notator (called Notator HD), but the demise of the former soon put paid to that project. The mission of integration that faces the MIDI software houses (should they choose to accept it) is somewhat daunting — it took Opcode over a year to adapt their top-flight Mac MIDI sequencer Vision to work with Sound Tools.

IS IT FOR ME?

The question arises, 'Is ADAS useful for me?', to which the answer is, 'It depends on what you want it to achieve'. If you own an Atari, some sequencing software and a few sound modules, you could buy a portastudio, plus a domestic DAT machine, and even a synchroniser for the price of ADAS and a 40MB hard disk. ADAS' audio quality is certainly better than a portastudio, but recording time is limited by (expensive) hard disk storage, and ADAS cannot perform overdubs. Nor can ADAS compete with a portastudio in terms of setting up time.

If you already own an analogue multitrack of some kind, ADAS' MIDI controlled recording facility will be useful, providing high quality vocal and live instrument recording plus the ability to edit songs into new shapes (bearing in mind the limitations described earlier). Buying ADAS simply to re-order the running time on cassette or DAT tape does not make economic sense since you could buy at least two DAT machines for the price of ADAS, the S/PDIF interface and a decent-sized hard drive. However, if you already own a DAT and a multitrack and an Atari, ADAS is currently the cheapest way to get in to direct to disk recording.

FURTHER INFORMATION

ADAS £839.00 (all prices listed include VAT)
S/PDIF Interface £359.00
DMA/SCSI Convertor £176.25

Plasmec Systems, (Contact Details).