COMCOCTION

Spectrum with interface fitted Lloyd Mangram plugs in programs and plays

The latest spate of joystick interfaces has brought a multitude of different programming concepts on the market ranging from the software selectables to the personalised card systems.

As the Sinclair owner is aware, the Spectrum does not provide a dedicated joystick port (rather odd for a games computer), and the add-on market has been quick to provide various solutions to the problem. Before this however, the software houses have had to make do with the keyboard as a playing ground. The multitude of key combinations used for each and every game meant that whoever would bring out a joystick which catered for all these games, would have to provide a system which used the input port address of the keyboard and could link any of the keyboard keys to any of the joystick controls. With five joystick controls and 40 keys this meant an astonishing amount of combinations and it is with no surprise that some manufacturers chose early on to create their own interface standard, leaving it to the software houses to develop compatible software.

The earliest and most established is Kempston, using a different input port address to the keyboard (input address 31). Fuller went along similar lines, but selected input port 127. Where Kempston was accepted as the joystick standard, the Fuller system suffered from the lack of support from most software houses (except Imagine).

AGF opted for part compatibility by using the keyboard port address and linking the joystick controls to the cursor keys and 0 for fire button. This was met with success too, and the cursor key joysticks (mostly AGF and Protek) developed into a standard.

Much of the software catered now for the Kempston and cursor joysticks and the last thing needed was another standard. Promptly Sinclair launched the ZX Interface 2 which was to provide the Spectrum with two joystick ports and a games cartridge interface to complete the arcade image of the computer. You guessed, a new Sinclair standard was created, with the joysticks operating off specific keys, one off the top right half-row, the other off the top left half-row of the keyboard. Although technically a good idea (each joystick requiring only one keyboard address for fast machine code access), it nonetheless created a further confusion on the market and the software houses had to provide a whole plethora of compatibilities. In exasperation, some programmers provided a soft option by including a ‘select your own keys’ routing within the program. A new interface was needed, which enabled all the games to be played with a joystick and which provided the user with a fast and easy programming system.

Frel Limited purport to have found the ideal solution with their COMCON interface...

THE HARDWARE

The COMCON comes in a brightly coloured package and impresses by its sheer size of 120mm width and 135mm depth with a sleek profile of 19mm excluding the extension port chimney stack.

Most of the top stack is taken up by a 4 x 10 matrix of two-pin connectors. This matrix represents the Spectrum keyboard and is annotated accordingly with a white legend.

Protruding at the rear are six two-core cables with Molex receptacles which can be plugged into any of the 40 matrix positions. These six cables represent the six joystick controls (4 direction and two fire) and are annotated at the entry point of the cables to the enclosure.

To the rear right is a 9-pin D connector plug, which will accept any Atari compatible joystick.

A vertical extension port is provided at the front of the unit and is protected by a collar which blends in nicely with the Spectrum’s rear enclosure. This extension port provides the possibility of connecting the Currah µSpeech unit or the Alphacom printer, both do not have extension ports (the Alphacom only provides a ZX81 extension port).

Overall the unit looks tidy and professional, the injection moulded enclosure being of good quality and the connectors rugged enough to survive any ill treatment from game addicts.

Interface & box

OPERATION

COMCON operates parallel to the keyboard using the same input port. Each joystick function is represented by a cable which can be plugged into any key position of the matrix. So if the game requires key Q for up movement, the ‘up’ function cable is plugged into the position marked Q. Simple!

Naturally if the program caters for diagonals, the joystick will automatically provide these as the diagonal movement of the joystick simply is the equivalent of pressing two keys simultaneously on the keyboard. As the interface operates on the same input port as the keyboard, there is no problem of incompatibility as regards to other peripherals. It goes to say that joystick and keyboard can be operated together without any electrical collision and that therefore multikey games such as Flight Simulation etc. can be enjoyed with the joystick and keyboard combined.

COMCON also provides two independent fire or special function actions (six cables). Frel Ltd market for this purpose a modified Quickshot 2+2 joystick which incorporates two independent trigger buttons on the grip (F1 = index finger operated button, F2 = thumb operated button) at the expense of the very little used Rapid Fire option. Also available from Frel is a special Flightlink joystick with two independent fire buttons which also makes full use of the fire actions on COMCON. The extra fire function proves to be very useful with arcade games (Cavern Fighter or Full Throttle should prove its potential!).

Any Atari compatible joystick can be connected to COMCON (Kempston, Quickshot 1, Sumlock etc.) although the second fire option will not be available.

The review team of CRASH has been operating COMCON for over two months and has had no compatibility problems so far. The major benefit of the unit is its ease of programming, beating any other system for sheer simplicity and speed. The possibility of programming the joystick functions during loading or even in the middle of play is invaluable. In fact most of the time the game is loaded first and the programming is accomplished after reading the operating keys in the screen instructions.

COMCONCLUSION

COMCON proves to be a perfect solution to the problem of joystick incompatibility with the Spectrum. Any program can be catered for. At £19.95 the unit is very good value for money. The choice is left to the Spectrum owner, whether to go for a two or three standard interface such as the RAM Turbo or Kempston (catering for Sinclair, Kempston and Cursor) with the added bonus of the cartridge port, or to be truly independent from any standard and gain an extra fire function!

EPILOG

Frel has informed CRASH that the latest Cambridge Computing joysticks have a revised pinout on the D connector affecting the 2nd fire action. Frel provides the service of modifying the COMCON interface to suit the Cambridge joystick 2nd fire function at a charge of £3 all inclusive.

At the same time the company offers to upgrade any Quickshot 2 joystick to the Quickshot 2+2 spec with two independent fire actions with the loss of Rapid Fire at a total cost of £4 all inclusive.