Entrepo QD Drive (Entrepo) Review | Computer Gamer - Everygamegoing

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Entrepo QD Drive
By Entrepo
Commodore 16/64/Vic 20

 
Published in Computer Gamer #3

Cassettes are unreliable but disks are expensive. Mike Roberts finds an answer to this dilemma for C64 and Vic owners

Entrepo QD Drive

Cassette storage is an unsuitable storage medium for home computers. It is only with us due to economics - i.e. it's cheap. Even the ubiquitous paper tape has a number of advantages over this unsuitable medium.

On the other hand, the main competitor to cassettes - floppy disks, are extremely expensive, running to hundreds of pounds a time (they were not designed for storage any more than audio tapes were, but for data transfer, however that's another story).

The disadvantages of tape are mainly slow speed, lack of direct access (try to record at the end of a tape), and unreliability.

Disks are also unreliable, but less so, and have quantitive problems when it comes to storage space - disks are between 100K for the smallest BBC drive at around £150, 180K for the Commodore 64 at around £175, to 640K for the modified non-standard BBC drive at around £300.

The storage media (i.e. the disks) all weigh in at about £2, though some people will try and rip you off with prices up to £4 for a single disk! Price is no guide to quality.

When you come to tapes, at £30-£40 tape deck and a £1 CPO will store about 300K.

As I previously mentioned, both these data storage devices were never originally designed for data storage, so getting down to the crux of the matter, the Wafadrive is.

What Is A Wafadrive?

Everybody has heard of the infamous Sinclair Microdrive, an attempt to provide a fast disk alternative. However it failed to live up to its claims, was unreliable, slow, had a low data capacity, and was badly supported by software houses.

Now a group of multinational companies headed by BSR/Astec (famous for their power supplies and modulators) and Entrepo have, over the last few years, developed their own wafer or continuous loop tape system. The system is, in concept, similar to all 'stringy floppies' that have been developed. A loop of tape that is joined at the ends. So that, if you want some data that is at the beginning of a tape and read head is just past it, it will wind on past the join until it is in the appropriate place to read it again.

So direct access is possible. The big unreliability problem comes with the spooling method. When you have unravelled the tape, you have to shove it back onto the spool again. This is where the Sinclair devices fall down; at this point, after continuous use they get all munched up - losing all data, programs, etc.

The Entrepo units do not have this problem, due to a highly developed tape system, lubricants, and various other systems to keep the tape tight.

In Britain, the system first saw the light of day with the Rotronics Wafadrive about a year ago, for the Spectrum. The unit since went on to win the CTA 'peripheral of the year' award.

However, other computer owners will not have to suffer any more. Dean Electronics are now importing the Quick Data Drive from Phonemark for the Commodore 64 and Vic-20.

The unit is very small indeed and is a lot smaller than the standard tape deck. Like the tape deck it plugs into the cassette port and requires no extra power supply. Quite a change from the heavy and large disk system with all its trailing wires.

The QOS (Quick Operating System) needs to be loaded so that the Commodore 64 can use the new system through the tape port. This is done by inserting the operating system wafer and hitting run/stop (where have I seen that before?) the QDD will emulate the tape recorder, and load in the program at normal tape speeds. This obviously takes a while, as 'normal' tape speeds are very slow indeed.

When booting has taken place, the commands LOAD, SAVE, VERIFY and the file handling commands all work through the QOS and go directly to the wafer at high speed.

The QOS does take up memory space though, and the 4K of spare RAM from $C000 is taken over. 4K from $A000 is also taken, but this is banked under Basic and is not normally used by the Basic user.

For normal disk-type commands, a separate program needs to be loaded, called a File Management Utility. The FMU provides tape to wafer, wafer to wafer, disk to wafer, and most other combinations of copying. It does not copy protected files.

The FMU also provides a directory display, formatting, system creation, and clean drive (this needs a cleaning wafer). It is a shame that these essential functions could not be provided in a permanent command-driven environment.

On the whole, the QDD is a very good alternative to tape; whether it will challenge disk or not is another matter as the price of disks is falling. The QDD is currently supported well by American software houses and there is a lot of imported software available for it.

If the price drops to significantly lower than disks, this will be well worth getting.

Mike Roberts

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