RCN REVIEW: DivMMC EnJOY! for Sinclair ZX Spectrum

The DivMMC EnJOY! mates well with Retro Computing News editor Stuart Williams' Sinclair ZX Spectrum +3
The DivMMC EnJOY! mates well with Retro Computing News editor Stuart Williams’ Sinclair ZX Spectrum +3

One of the most useful developments in retro computing and retro gaming in recent years has been the introduction of ‘digital hard drives’, created by means of interfacing digital camera memory cards via custom IDE interfaces, to speed up the use and enable the expansion of many aging but still serviceable computers. This is a great convenience – especially for those machines which were never intended to have such drives!

Of course, ‘back in the day’ – the 1980s-90s – for typical home computers, many programs were available only on slow and not always reliable audio tape cassette, and typically the most advanced storage system for such machines as, for example, the British Sinclair ZX Spectrum range, was nothing better than a microdrive tape loop system or a floppy disk with a few hundred kilobytes of capacity at most.

So it was that the most enthusiastic of home computer owners inevitably ended up with a large collection of tape cassettes or floppy disks, and it was only in the late 1980s, when the 16-bit and PC era began to get underway, that the average user could even think of owning, for example, a whopping great ten or twenty megabyte hard drive!

FLASH – A-HAA!

In recent years, then, a great boon to the growing numbers of retro computing enthusiasts, especially gamers, has been the invention of such very clever, and affordable, compact IDE interfaces. They offer the capability of clipping in a CompactFlash or, more often of late, SD card, with a few electronic components and some clever firmware to provide, in effect, a disc operating system or DOS – thus forming an affordable and high capacity solid state drive system with capabilities which would have been a mere pipe dream in the 1980s.

The enormous advantage of such a system is, of course, that it enables the mass storage of the hundreds, thousands, or – in the case of the Sinclair range, tens of thousands – of games and other programs which, having in many cases been abandoned by their past publishers, many of whom are no longer in business, are readily available online as digital files, in various formats, for use with emulators.

DivMMC EnJOY!
Top and bottom views of the DivMMC EnJOY! in its 3D-printed case
Top and bottom views of the DivMMC EnJOY! in its 3D-printed case

One such system was launched for the Sinclair ZX Spectrum range of computers last year by Ben Versteeg of ByteDelight.com in the Netherlands, who is well-known in the world-wide retro computing community.  It is called the DivMMC EnJOY!

The DivMMC EnJOY! (sic) followed its earlier, widely-used predecessor, the DivIDE, in similar vein, but upped the ante by adding an SD-card slot, which since most PC and Apple Mac computers now have either a built-in SD card slot on the computers, or can take an inexpensive USB-connected SD card reader, makes it a no-brainer for simple file transfer from PC/Mac to Speccy. This is particularly handy if the user has already sourced a large collection of games for use with emulators, for example.  It also has 128k of RAM by default, four times that of the DivIDE.

The new device also added a very handy joystick interface – Kempston compatible, being a natural choice as one of the most popular options for Sinclair Spectrum computers – which allows the use of a single Atari-compatible joystick with the many games that offer the Kempston option.

DivMMC EnJOY! in operation on the ZX Spectrum +3
DivMMC EnJOY! in operation on the ZX Spectrum +3

The device has two simple controls – blue push-buttons, the NMI button (right) offering a simple break-in loading menu and command system, the other (left) a handy reset button. When fitted to the expansion edge connector of the computer, these buttons offer a direct means of loading programs from the SD card, as the DivMMC EnJOY! overrides the loading menu of the 128k Spectrums. Two green LEDs indicate power on and card access.

The top level of the ESXDOS file menu
The top level of the ESXDOS file menu

The operating system DOS built-in to the DivMMC EnJOY! is ESXDOS, a FAT and FAT 32-compatible filing system which allows the selection and running of programs by use of the computer’s cursor and enter keys. Support is built-in for various emulator formats, including .TAP, .SNA, .TRD and more.

First screen of the Games folder as currently set up on the editor's DivMMCenJOY!
First screen of the Games folder as currently set up on the editor’s DivMMCenJOY!
COMMANDS

ESXDOS also offers a range of commands which may be used from BASIC in the following format: “command <args>”

Most commands are self-explanatory or show onscreen help when run without arguments (or by adding the -h parameter).  Most  (but not all) commands and parameters are listed below:

GOTO [drive] [“path”]

CAT [drive]

LOAD drive “path/filename”

SAVE drive “path/filename”

ERASE drive “path/filename”

-c   Close file

-o   Overwrite file

.ls   Show directory listing

.cd somedir   Change directory

.tapein somefile.tap   Attach .tap file for reading

.tapeout somefile.tap   Attach .tap file for writing

.mkdir newdir   Create new directory

.mv oldname newname   Rename/move file/dir

.cp source target   Copy file

.more textfile   Display the contents of a text file

.chmod +h somefile.sys   Set/unset attributes on file/dir

There is also a TRS-DOS emulator, of all things! The DivMMC EnJOY! firmware is updatable, and can be flashed as updates are made available.

It is also possible, via the NMI menu called up by the right-hand blue button, to create an auto-incrementing snapshot file for a game, allowing the game to be continued later.

WHAT’S IN A NAME?

ESXDOS, while very useful and simple to use, does however have an obvious limitation at the moment – long filenames are not possible, which can make things a bit confusing if you have a lot of games with similar names!  A little planning is, therefore, necessary when setting up folders and naming files.  Possibly it might even be worth considering having different SD cards for different types of game if you have a large collection.

There are slight differences between the different Spectrum models, which means that the DivMMCenJOY! has to be customised according to the machine with which it will be used. In practice, this is simplicity itself, being done by flipping a set of four DIP switches on or off before fitting the device onto the computer’s expansion edge connector.

Dip swtch settings for different Spectrum models
Dip switch settings for different Spectrum models, in this case set for Spectrum +3
OUR OPINION

This may all sound a little complicated, but in fact the typical user is most likely just going to want to copy loads of games in .TAP format, typically from online sources such as World of Spectrum, onto an SD card using their PC or Mac, pop it into the DivMMC EnJOY! and, having set the jumper configuration for their particular model of ZX Spectrum, plug it into the expansion conector, turn the Speccy’s power on and start playing straight away!

In practice, this works well, and with all the other commands offered via BASIC, there is plenty to play with if you want to get down and dirty with the filing system.

The case in which the well-made circuit board is supplied is a little rough and ready, being 3D-printed, but is attractive enough and doesn’t look out of place behind a Speccy, though it does stick out a ways. Thankfully, it doesn’t seem to wobble much, and our editor Stuart Williams has not had any crashes since purchasing the device pictured last September.  It fits well on both his Spectrum +3 and Spectrum 48k. Your mileage may vary, depending on the type of Speccy you own and the condition of its edge connector.

The only slight niggle, as far as Stuart is concerned, is that the positioning of the joystick interface means that the joystick plug and cable can intrude into the screen area if the TV or monitor are close to the back of the computer. But that’s the nature of such interfaces on the Speccy – something’s always popping up!

The DivMMC EnJOY! is supplied with a 4gb MicroSD card in a full-size adaptor, formatted and with a few folders, system tools and demo files already set up, so getting started could really not be more simple than that.  The supplied instruction sleet is a little slim, but offers enough to get going.  You will have to look up TRS-DOS yourself!

CONCLUSION

Apart from the vastly-increased speed and reliability of program loading – practically instantaneous, even with 128k programs – there is an enormous convenience and security which this type of device offers the retro collector. You can still collect all your favourite boxed games etc in physical form and simply run your digital file collection from SD card without subjecting your precious tapes to the distinct possibility of strangulation by a cassette recorder!

Indeed, such are the advantages of SD card storage of this kind you could well find that, if you buy a DivMMC EnJOY!, your newly-acquired little black box will find a permanent home behind your Spectrum while that battered old cassette recorder languishes in a cupboard or, dare we say it, the loft. Except, of course, for when you dig it out for the simple pleasures of all that retro fun of loading screens, loading screams and loading errors…

We certainly think that the DivMMC EnJOY! is a great convenience, a great idea and a great product.

The DivMMC EnJOY! Black Edition (there was originally a white cased option) is currently being offered by Ben Versteeg on his ByteDelight.Com website at the bargain price of £59.99, reduced from £74.99.

So if this meets your needs, why not beat a path to his door?  Your dear old Speccy will thank you for it!

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