The following article was taken from Your Sinclair Issue 5 - May 1986
What does a Wafadrive offer me that I can't
get from my cassette ?
Speed's the obvious answer - it takes
just 40 seconds to load Spectral Writer, the free word processor that comes with
the Wafadrive from a 16k wafer. But the really big advantage is that you can store
programs as files on a wafer. It's a real chore finding where you've put a particular
program on a cassette, especially if you've got loads and loads of them on there.
So just how fast is a Wafadrive ?
Well, it all depends on the position of
the tape in the wafer and it depends on the size of the wafer. But as an average, Sherlock
on a 64k wafer takes 43 seconds to load. You can uaually reckon on 2k of bytes going in
every second plus the access time.
So it's not as fast as a microdrive ?
That depends as well. You're right, its
not as fast at loading in the data. But, if you take into account the Wafadrives
more friendly operating system and its easier command syntax, you'll probably find it
takes you no longer to load in a program. All that "m";1; stuff goes straight
out the window. It's just LOAD * "filename" and your away.
Yes, but what about reiability ? The reason
i've been put off microdrives are all the stories about
how unreliable the cartridges are.
Microdrive cartridges do have a finite
life but there's no way you're going to wear out a wafer cartridge. There's more tape in a
wafer than in a microdrive cartridge so it's under less stress. And the protective cover
that slides across when the tape's not in use stops people putting their grubby fingers
all over your tape.
What other advantages are there over
Other than performance, you mean ? Well
now there's price. £45.95's what you'd pay for a microdrive without the interface 1 - the
Wafadrive plugs directly into the back of your Speccy, of course. And remember, you get
two drives on a Wafadrive just like on a professional system.
[Note: This article was
published when the Wafadrive was selling at £49.95]
Why are there three different sizes of
wafer cartridge ?
That's so you can choose the most
appropriate size for the job you want it to do. The larger the memory, the more tape in
the cartridge and the longer it'll take to access the files. So, there's no point in
choosing a 128k wafer to store programs that you're loading frequently. Much better to
develop your programs on a small wafer and then transfer them onto a 64k one that has
planty of storage and medium access times. The 128k wafer is really only useful for
archiving because of the longer access times. but when you do want an old program, you can
quickly find it by CATing the wafer - try that with all your old cassettes.
Is the capacity of the wafers exactly 16,
64 and 128k ?
No, that's just for convenience. On
average you could expect to get about 75k on a 64k wafer and anywhere up to 140 odd k on a
Can I connect any full size printer via the
Centronics and RS232 interfaces ?
Yes - with the one exception of the MCP
I'm used to word-processing with Tasword
II and i'd like to continue with it - is it possible to
transfer it to Wafadrive ?
Yes. You can get an information sheet
that shows you how to do it directly from Rotronics. For anyone who hasn't used a word
processor before, Spectral Writer will fulfil all your requirements.
Is it easy to transfer programs from
cassette onto Wafadrive ?
If the programs are in Basic, you've
got no problems. Just load them in, then save them onto the Wafadrive. Machine code
programs can present more of a problem, especially if they're very large and don't leave
around 2k for the Wafadrive Operating System. You'll find the transfer utility on the
Rotronics Toolkit wafer very useful. It also includes routines to COPY to Epson printer,
print graphics from Basic, a printer channel driver, a de-initialise routine and a file
The following review
was taken from Home Computer Course 1985
The initial lack of a reliable, fast
storage medium has meant that the Sinclair Spectrum has generally been overlooked as a
machine for serious applications. The introduction of Sinclair's own Microdrive system,
however, did not deter independent companies from producing storage systems such as the
Although the Sinclair Spectrum has become one of the most
popular home microcomputers, it has been criticised in many quarters as being unsuitable
for the 'serious' user. This has led to the Spectrum being dismissed as merely a games
machine. Part of the problem has centred around the keyboard, which has not allowed the
user to seriously consider using the machine for applications such as word processing and
database management. Recently, Sinclair Research has attempted to defuse some of this
criticism by launching the Spectrum +, which is fitted with a QL-style keyboard.
However, this is only part of the problem. Other difficulties hounding the supporters of
the Spectrum as a serious machine are the computer's lack of standard interfaces and, more
importantly, a fast and reliable mass storage system vital to any business or serious
application for the hobbyist. Of course, with the introduction of Interface 1 and the
Microdrive, the Spectrum could at least claim to have these facilities available. But the
suspicion remained that the Microdrive was slow and unreliable. Furthermore, although the
software base on cassette for the Spectrum is enormous, very little software has made the
transition to the medium used by the Microdrive. In a situation like this, third party
suppliers tend to step into the gap and produce alternatives. Here we look at the first of
two contenders in the race to dominate the Spectrum mass storage market - the Wafadrive
Unlike Interface 1 and the accompanying Microdrive units, the Rotronics Wafadrive is an
'al-in-one' unit. That is to say that both the peripheral interfaces and the mass storage
units are enclosed in a single box. The advantage of this system is that the units do not
have the trailing leads necessary for the Sinclair system, but it does mean that they lack
something of the flexibility of the Microdrives, which can be daisy-chained together to
expand storage space.
THE LOOK OF THE MACHINE
The Wafadrive is encased in black plastic with a 35-way ribbon cable ending in a cartridge
slot fitted onto the Spectrum's expansion bus. On the front of the unit there is a pair of
wafer cartridge drive slots. Between the slots are three light emitting diodes (LEDs). The
central light is the power-on indicator, while the other two indicate drive activity.
On the rear of the drive unit are three edge connectors. On the left is a parallel
expansion bus to allow Interface 2 to be connected. The centre edge connector is a
Centronics-compatible interface to allow the drive to be attached to a parallel printer.
The third is an RS232 serial port that enables the device to be interfaced with modems and
other serial devices. These interfaces are an improvement over those provided on the
Sinclair Interface 1, where, for example, one still has to connect a second Centronics
interface to the units edge connector in order for it to run parallel printers.
Unfortunately, however, users will still have to shop around for Centronics printers or
modems with Wafadrive-compatible cartridge connectors.
The stringy floppy wafers specifically designed for the Wafadrive are in many ways similar
to those used on the Sinclair equivalents. Inside each wafer is a continuous loop of
video-type cassette tape with a width of 1.8mm. This tape is used instead of the more
conventional audio tape because of its improved endurance and information storage
capabilities. Once formatted, this tape can contain approximately 128 Kbytes of data,
although Rotronics has also made 64 and 16 Kbyte cartridges available.
The cartridges themselves are approximately twice the width of the Sinclair waters,
although they are of similar length and breadth in their protective boxes. This gives the
Rotronics cartridges an appearance of miniature cassettes. The Wafadrive cartridges do not
need protective casings, as the delicate tape is protected by an automatic sliding cover,
similar in design to that on the Sony 3 inch microfloppy disks, although the Rotronics
protection is made out of plastic instead of metal. On the left side of the wafer is a
write protect tab, which can be snapped off. Of course, this tab cannot be replaced once
it is broken off and users will have to find some other method of re-enabling their
The commands used by the Wafadrive are more or less identical to those used on the
Sinclair Microdrives. In both systems the command is followed by a , indicating that the
external storage device is to be accessed. Examples of this usage are SAVE * , LOAD * and
VERIFY *. However, the Wafadrive system does have slight differences because there are
always two wafadrives present, as opposed to the numerous Microdrives that could be in the
system. For example, when formatting a Sinclair wafer one uses the command FORMAT 'm' ;0;
"name", where m;0 refers to the number of the Microdrive being used. When using
the Wafadrive, the command is altered to FORMAT * 'a:name', with the a: referring to the
name of the drive in use. Note that with the Wafadrive, there can only be a section a: or
b:, whereas on Microdrive the number can be from zero to seven.
THE 'STREAM' SYSTEM
The Wafadrive also takes advantage of the 'stream' system used on the Spectrum, in which
there are 16 streams set aside for input/output management. Some of these are reserved for
use by the screen and printer. However, channels four to 15 are available to other
peripheral devices, and output streams to the Wafadrive are accessed by use of the OPEN #
command. The Wafadrive also adds two extra streams to the system. Channels r and c (these
letters can also be capitalised) are reserved for the RS232 and Centronics interfaces,
respectively, and their usages are similar to the t and b channels - used when accessing
the RS232 port on Interface 1.
There is an eight Kbyte ROM on board containing the extended BASIC commands used in
controlling the system. This Wafadrive Operating System (WOS) is able to function by
'paging out' the lower eight Kbytes from the Spectrum's ROM, in much the same way that
Interface 1 does. For example, the command LOAD * actually generates an error on the
Spectrum: thus, when the BASIC interpreter encounters this command on the screen, it will
call the error-handling routine. However, this call command will be intercepted by the
WOS, which will then page in the Wafadrive ROM. This in turn will take over the error
handling and interpret LOAD * as a command.
Compared with the Microdrives, the Rotronics Wafadrive is somewhat slower. For example, a
100 Kbyte Microdrive requires an average of 3.5 seconds to locate a piece of information,
which is then transferred to the computer at a rate of up-to 19.2 Kbaud. The Wafadrive, on
the other hand, can only manage a maximum transfer rate of 18 Kbaud, with a maximum access
time of 45 seconds on a 128 Kbyte wafer. This is significantly slower, although this
relative sluggishness is partially compensated for by its increased reliability. However,
it must be noted that the Sinclair Microdrives were consistently faster than the Wafadrive
in benchtest timings.
Although these access times are much faster than could possibly be achieved on cassette,
they are still slower than comparable disk drive times. However, the Wafadrive, like the
Microdrives incorporates a handy procedure when accessing the tapes catalogue. The
catalogue is held on the first sector of the cartridge after the splice joining both ends
of the tape together. Thus, to CATalogue a wafer, the drive has to wind the tape until it
discovers the splice and can read the next suitable sector, After several seconds, the
tape head will be past the catalogue sector. However, should the CAT command be entered
again, instead of winding the whole of the tape round again, the drive will move for only
a fraction of a second before displaying the catalogue again -it will be held in RAM once
it has been called. Thereafter, the WOS merely checks to see whether the same wafer is
inserted by looking at the next sector. If it is, the WOS will display the catalogue it
already holds in RAM.
In keeping with the idea of implementing a mass storage system
allowing the Spectrum to be used for more serious applications, Rotronics has included the
Spectral Writer word processing program in the package. This is a relatively comprehensive
system making full use of the Wafadrive. Functions such as reform paragraph, insert words
and delete lines are called by using the Spectrum's Symbol Shift key in conjunction with 5
other keys. Other functions that access files held on wafer can be obtained by means of
the options command: these include SAVE and LOAD text files from cassette or from
Wafadrive. Spectral Writer is a fine word processor, although it does not enable you to
set the line length on the screen. It is perhaps unfortunate that even when using a
Spectrum+, the quality of the keyboard somewhat diminishes the Spectral Writer's
Of course what makes or breaks any storage medium on a computer is the willingness of
software houses to support it. At the moment this seems to be a serious drawback to the
Wafadrive's success, since none of the major software houses are producing their programs
on Wafadrive cartridges (this is also a problem that has been encountered by Sinclair
itself). However, all is not lost for the Wafadrive user. At least one company is now
producing a program that enables you to dump commercial software onto Wafadrive
cartridges. This means that users will be forced to buy both the commercial cassette and a
wafer to transfer it to, but a small price to pay for the vastly improved access times
that are produced.
Another minor difficulty of the Wafadrive is the edge connectors on the back of the
machine. Because they are non-standard, users must be willing to convert the interfaces
themselves, or else they will have to look hard for peripherals with suitable connectors.
But, although the Wafadrive does have its drawbacks, it is a finely made machine, and
certainly a viable alternative to the Interface 1 and Microdrive provided by Sinclair