Cambridge Joystick & Interface

Sinclair User

INDEPENDENT JOYSTICK Voltmace has launched its new joystick - the Delta 3S. Unlike most joysticks it features two independent fire buttons, one of which can be used by either left- or right- handed players, and rotary switches are used on the stick. Those switches give it a very light action and the stick can be comfortably held in the hand. Together with the joystick Voltmace is marketing two interfaces. One, made by Rainbow Electronics, is hardware-programmable and the other, from Cambridge Computing, requires software. The Rainbow interface also incorporates a beep amplifier. The stick has a standard nine pin Atari-style plug and so will work on any interface. Priced at £10.00 the joystick is good value and its solid construction should ensure it outlives most competitors. The Cambridge Computing interface costs £22.95 - £29.95 with joystick - and the Rainbow interface is £29.00 - £37.00 with joystick. All prices include VAT and p&p. They are available by mail order from Voltmace Ltd, [redacted].

ZX Computing

INTERFACITS - JOYSTICK INTERFACING INVESTIGATED A comprehensive round up of the units available - checked out by our team of reviewers. One of the first add-ons that a computer owner may contemplate buying is a joystick of some kind. The increase in control that this provides is of obvious benefit to the dedicated games player. In addition it is becoming increasingly necessary for some of the complex graphics packages that are appearing for the Spectrum. However if you have not yet taken the plunge and are now contemplating the purchase of some form of controller you have a difficult choice ahead of you. In essence, most of the actual joysticks are very similar, and your eventual purchase will be based upon personal preferences for shape, size, ease of use etc., but the biggest decision to make will be that concerning the vital link between your joystick and the computer i.e. the INTERFACE. Interfaces allow the use of joysticks with compatible software, and although there is a great variety of material available for use with all the more common interfaces no single one will give you control over every game, unless, of course you opt for a PROGRAMMABLE INTERFACE. These claim to give you joystick compatibility with ALL software. NON PROGRAMMABLE KEMPSTON £11.95 Probably the nearest thing to a "standardised" interface. This unit has been around almost as long as the Spectrum itself and most games have a Kempston option. The unit works by utilising the IN31 function and so the keyboard is not enabled. This also means that a program must cater specifically for it and some of the earlier games don't. To get over this Kempston market a set of tapes which will convert some of these to operate with their interface, each of these will cost £4.95. The box plugs into the port of the back of the Spectrum and the joystick plugs into a standard 9 pin socket at the front of the unit. This means that the joystick leads trail over the keyboard and if you have a full sized keyboard then this plus the fact that the box has a "lip" means that fitting it is a great problem. Although it's starting to show it's age there's still plenty of life in this well tried and loved device. INTERFACE II Sinclair Research £19.95 A multi purpose unit which includes two joystick sockets, a ROM cartridge socket and a limited through port. Sir Clive in his wisdom, decided to use his own "standard" for operating his interface and this is not the same as Kempston. This means that many of the earlier games will not operate with it although most of the recent programs incorporate an Interface II option. In fact many games have a larger choice of joystick options than gameplay options! When provided, two joysticks can be used simultaneously and this is the greatest advantage of this unit. It has been on the market for quite a while now and the presumed flood of cartridge programs has not materialised. This is really the power of this unit and if they are not going to be produced then it has limited value as a joystick interface. RAM TURBO RAM Electronics (Fleet) Ltd. £22.95 Similar to the Sinclair Interface II, this unit has two joystick sockets and a cartridge slot, also has a through port but in the Turbo it is a full one unlike the Interface II. The Sinclair format is not used, but both Kempston (IN31 and Protek (cursor keys systems are supported. I don't know if this means that only one joystick at a time can be used and we never received a review unit. GAMES ACE VOX BOX Datel Electronics £29.95 Although requested, neither of these units were sent for review, so I'll just give a mention of the information available. Games Ace works on the Kempston function so it will be compatible with that option, it also has the bonus of including circuitry to output the sound to the TV where the volume can be controlled. Vox Box is the same as the Games Ace but also includes speech synthesizer based on the allophone system. Sounds interesting. PRO JOYSTICK INTERFACE Kempston Micro Electronics Ltd. £19.95 After a long run with their bes selling interface Kempston have decided to introduce this mode;. Similar in many respects to the Sinclair Interface II it seems much more versatile. As it's hot off the production line we haven't yet seen one. However, I'm told that it has three separate 9-pin plugs which cover Kempston's own system, Sinclair I/F II standard and the AGF/Protek cursor key format. There is also a ROM cartridge port. With Kempston's experience in the market it's got to be worth a look. SOLIDISK Technology Ltd. £8.50 One of the cheapest interfaces on the market, this one operates on the Kempston standard and is claimed to be wobble free. Sold complete with a Quickshot-style joystick for £15.50. Even more useful is that should you forget to change the switch or get the wrong option then you can safely change the option once the program has been loaded and is actually running! An interface which I would recommend to any dedicated games player who requires a simple, effective means of joystick control. Protek also market a presentation pack of joystick, interface and their own flight simulation program for £24.95. AGF JOYSTICK INTERFACE II £9.95 AGF have two joystick interfaces on the market at the moment - one programmable and the other not. Interface II is the non-programmable one, but there are versions for both the ZX81 and the Spectrum. The interface will accept a wide range of joysticks including Atari, Starfighter, Le Stick etc. and has facility for a second joystick to be used. There isn't much to it in the way of hardware, just a few plugs and sockets and six chips. I noticed they have rubbed off the numbers on the chips to deter people making their own, but at £9.95 it's not worth the bother. The interface just clips on the back of your computer and has a rear extension for more add-ons. With a joystick plugged straight in it will mimic keys 5, 6, 7, 8 and 0 and the second port will give you T, Y, U, I and P. To convert games that do not use these keys, you will have to purchase AGF's software and you have a choice of two cassettes. Tape one will convert Arcadia, Schizoids, Hungry Horace, Horace goes Skiing, Spectres, Penetrator and tape two converts Centipede, Planetoids, Jet Pac, PSSST, 3D Combat Zone and Invaders. After you have loaded the cassette it will ask you which game you would like to play and after running the tape further it will automatically find the corresponding software to convert that game and tells you when to load your game. On the inlay, it lists the games you can use the interface with. I would have thought it would have been better to list the key operations as well so that it would be easy to find what other games you could play with it. You can buy the interface, software and joystick direct from AGF if you cannot find it at your local store. Cassettes are £4.95. It is a slightly 'Heath Robinson' way of connecting a joystick but it is cheap. DK'TRONICS JOYSTICK INTERFACE DK'Tronics Ltd. £13.00 Another little shiny black box (7 x 5 x 2.5cm.) to get quickly forgotten somewhere between joystick and computer is the DK'Tronics Joystick Interface. It has a firm positive fit into the expansion port at the rear of the Spectrum, although because only 22 of the contacts on the edge connector are used, the actual fitting tends to require more care and caution than with other units. There are two nine pin, 'D' type ports at the top of the unit and both are clearly identifiable. The first is for use with software using a key change option or using 6, 7, 8, 9 or 0 keys. The second port uses the IN31 command is therefore for use (software compatible) with the Kempston type joystick. The test routines and a few example programs (one using machine code) are given in the accompanying instruction leaflet, for those people who want to stretch themselves beyond being mere players, who want to incorporate their joystick and interface into their own programs. And for those programmers who want to use two joysticks to control two separate objects at the same time on the screen, then both ports of this interface can be incorporated simultaneously into programs. Just out of interest, I wonder how many micro-users actually do use their joysticks and interfaces for anything else besides playing commercially produced games? PROGRAMMABLE INTERFACES Rainbow Electronics £24.00 (+3.00 extra for a through-port) Another interface which never made it to our office in time for this roundup. The interface includes a built in amp and speaker, the joystick socket and the programming switch are positioned at the front (with all the associated problems). CCI (Cusom Cables International) £15.00 This unit is programmed by means of software supplied on tape, and this means that you have to load in the program supplied before loading your game. This isn't a great problem as it is a short program and setting up the keys is straightforward and only takes a few minutes. The unit we had didn't have any instructions. CCI promise that they are supplied with each purchase - we just had "a very early preview model". Nevertheless I found it simplicity itself to operate even without them - which can't be bad. The only problem is that some games don't tell you which keys the program uses so you have to load them in first to find out! This is only a problem the first time round because, being sensible, you kept a record for the next time, didn't you? The unit proved reliable and effective over a three week period of constant and frequent use and I see no reason why it shouldn't perform admirably for a long, long time. At the price it is probably one of the cheapest of it's kind and worth considering if, as it is for me, money is a prime factor. PROGRAMMABLE JOYSTICK INTERFACE Stonechip Electronics £24.45 As with most similar interfaces this is simply a plug-in unit which requires no additional links such as flywires of extra tapes to load. The unit itself measures 90 x 75 x 35mm and is contoured to fit snugly to the rear of your Spectrum. It features a three-way switch at the front enabling the user to select any of the three modes; Program, Play or Normal operation (where control relies upon the keyboard alone). The interface draws its power from the computer and a small red L.E.D. indicates power on. A standard 9 pin Atari-style joystick socket allows the use of your favourite zap-em-stick! It is at this stage that my first complaint appears. No doubt many satisfied users will disagree, but why, when an increasing number of games require the use of at least two extra hands, does the port have to be placed so that the joystick lead runs right across the keyboard? Programming of the interface is fairly easy - set the selector to the Program position, press the appropriate direction key and move the joystick into the relevant (or not so relevant) position. The small, but adequate, instruction sheet advises that the most complex functions be dealt with first and this gives rise to the second little quibble. As opposed to certain other interfaces available, the Stonechip requires the FIRE function to be input separately for each and every direction. This is sometimes not all that easy when you require one hand for the keyboard, one for the fire button and direction and one to stop the mobile joystick from sliding off the table! Apart from that, the programming of this interface is a straightforward, it not lengthy, process. Programming complete, just move the selector to Play and away you go! One additional feature is the Normal position that allows the joystick to be removed without loss or corruption of the keys already programmed. The unit was tested with a variety of joysticks and performed perfectly well with all of them. Included in the instructions is a sample program to enable practice - programming prior to testing on the real thing. If a Programmable interface is the sort that you require then this should be considered. It is slightly expensive in comparison to some of the updated and newer models now appearing, but nevertheless is a tried and tested product that has stood the test of time. THE CAMBRIDGE JOYSTICK INTERFACE £34.95 (including joystick) This interface has a through-port at the back which is very useful for using other units like speech or sound devices. The unit also has a lip on the front to help prevent "wobble" but if you have a non-standard keyboard it gets in the way. There is the usual nine pin plug on the left hand side for the joystick and the overall size is 11.5cm x 3.5cm x 7.5cm. To use the interface you have to load a tape first which programs the interface to respond to the appropriate keys. If the game you're using fails to give this information on the instructions then you have to load the game first to find out! However once you have programmed a set of key-sequences, they can be saved on tape (the reverse side of the tape has been left blank for this purpose and provision is also made for saving to microdrive) and many games can be saved at one time. You are able to check the joystick position at the end of the programming sequence. This interface is sold complete with a joystick and tape - the joystick is available separately and is reviewed as such. The interface is a bit fiddly to use but has proved compatible with all software tried, but when an option of joystick or keyboard is offered from within a program, you must use the keyboard one as the joystick option frequently does not work. PROGRAMMABLE JOYSTICK INTERFACE Downsway Electronics (UK) Ltd. £22.95 The Downsway Programmable Interface, which has been available for quite some time now, is at first sight rather a plain black unit which plugs directly into the Spectrum's rear expansion port. It measures 65 x 95 x 25mm and has a dual-position switch on the rear and a standard 9-pin joystick socket on the right side of the unit. This is one of the advantages that this interface has over some other units currently available, in that the keyboard is left uncluttered by control cables and therefore can be used in conjunction with the joystick. This gives the user a wide range of control options which can be a distinct benefit considering the handful of keys that some programs demand. A small instruction sheet provided with the interface gives all the information that is needed to make your joystick compatible with any program. Programming of the interface can be achieved either prior to loading a game or after the game has loaded. This facility takes care of all those programs that have no detailed instructions on the cassette inlay. To use this unit is simplicity itself - with the dual position switch in 'program' mode press the key for the specified command and move the joystick to the appropriate position. Release joystick and key then repeat for all other movements. In essence that's all there is to it! After programming (a few minutes work) switch to the 'play' mode and away you go! In operation the unit performed perfectly and on the odd occasion when a mistake was made it was a simple matter to re-program the offending key without the necessity of going through the entire procedure again. The FIRE command is independent of direction command and this means that FIRE has only to be programmed once, as opposed to the multiple movement/fire operations needed with some interfaces. The unit was tested with several joysticks ranging from the cheapest to one of the most expensive available and it performed equally well with all, the only noticeable difference being a somewhat coarser movement with one of the cheaper joysticks. Of the many programs used with this interface only two gave any problems - keys could be programmed but pressing the fire button caused the game to restart. As it happens the particular games weren't intended for joystick use anyway! In conclusion, if a joystick interface is high on your list of priorities then it may well be worth your while paying a bit more for the extra flexibility that this excellent little unit provides. FOX PROGRAMMABLE INTERFACE Fox Electronics Ltd. £34.95 I have used this unit consistently over a four week period with a wide variety of games and I recommend it to anyone looking for such a unit. It is a rather large unit and the long suffering DK'Tronics keyboard needed another bit removed before it would fit! The standard case presents no problems however. The unit has a through port so you can use other interfaces behind it, the Currah micro speech unit worked fine at the back, and the standard 9 pin joystick socket is near the bottom of the right hand side of the case. just above the socket is a small, two-way (up/down) switch. On power up the switch should be in the down position - switching it up instantly presents on screen a menu of 16 possible combinations of responses and options to create or select a set or to exit. The more knowledgeable among you will have worked out that the unit must contain a programmable chip of some sort. The program and set of key combinations are kept permanently refreshed by a battery which is constantly recharged. What happens if something goes wrong? The interface is supplied with a back up tape and also your own sets of positions can be saved on tape and easily reloaded into memory if needed. A few times I had to perform this operation due to the awkward fit with the keyboard but it was no real problem. Documentation is good, covering all the operational details and also how to use it as a pseudo ROM. All in all easy to use and one of the most impressive joystick interfaces I've used. AGF PROGRAMMABLE JOYSTICK INTERFACE £26.95 AGF sell a version of this interface for both the Spectrum and the ZX81 and both cost £26.95. The interface works by duplicating the keyboard layout with a grid of wires. The wires ending in crocodile clips can be attached to the various grid wires to route specific keys to the joystick. This means that all games can be controlled by joystick although you must use the keyboard option and not the joystick one when provided. The joystick is connected by a standard 9 pin 0 socket so it is compatible with the majority of the sticks on the market, two sockets are provided for two sticks for two players to play alternatively. Both sockets operate on the same keys and both sockets and the keyboard are always operative. A possible cause for dispute when used by two players! A set of quick reference cards, a demo tape and a stick on chart completes the package. The sight of uncased wires and chips may put off some users, but treated reasonably, this is an almost foolproof method of providing joystick control to any game. The unit has a through port and further peripherals can be added afterwards, I used a Centronics interface and a speech unit with it and had no problems. SWITCHABLE INTERFACE Protek Computing Ltd. £19.95 An interesting and unusual idea from Protek is to provide the ability to switch between the common interface options. The interface has a three way switch at the back marked, logically, 1, 2 and 3. Setting the switch will give you compatibility with Protek/AGF (cursor keys), Kempston and Sinclair Interface II formats respectively. Between these three options I should think that around 90% of the software on the market can be used with this unit. The only programs which will cause problems are those where no joystick options are provided and keys other than the cursor keys are used, and there can't be many of those! The case is quite small and neat with the usual 9-pin plug fitted in the right hand side of the unit. This is a handy position to allow the joystick lead to clear the keyboard. The instruction leaflet is as I like them, written in a simple step by step manner with diagrams - if you get it wrong it certainly won't be Protek's fault. My biggest criticism is the lack of a through-port, but with other devices available to compensate, it's not as drastic a problem as it used to be. Using this is a delight, even though most programmables are quickly and easily programmed, sometimes it doesn't seem worth the bother. With this one, compatibility is usually available at the flick of a switch. FIRMWARE PROGRAMMER INTERFACE £29.00 SOFTWARE PROGRAMMER INTERFACE £22.95 Voltmace Ltd. Two other interfaces unseen by us. One is programmable by using a two-way switch and the other by using a program on tape. The most interesting item that I've seen from this company must be their Delta 3 joystick, which has a rectangular base, three fire buttons (to allow for individual styles of holding the thing), and a fingertip type joystick at £10.00. PACE COMPUTING This company advertises a programmable interface for £26.00 which they say does not disable the keyboard and can be reprogrammed during a game. No further information is available so far. EAST LONDON ROBOTICS LTD. £15.00 Designed to be sold with their Trick Stick (of which we're still waiting for a review sample), it appears to be similar to the AGF programmable interface, in that flyleads which are connected to pins to mimic the keyboard are used. If bought with the Trick Stick, then it will only cost £10.00, which can't be bad! DK'TRONICS LTD. £22.95 This is Dk'Tronics deluxe interface and is programmable from the keyboard by using the switch provided on the top of the unit, or via the program supplied on tape. There is only one socket provided on this model, but as it is fully programmable there isn't any need for two separate sockets to cover the different methods of providing control. The socket is located on the top of the interface next to the switch. During operation, the keyboard is still enabled so that complex games requiring more than five keys to be pressed can still be played. At the time of going to press we haven't been able to obtain one because they're short of stocks, however Ms Green of the company assures me that by now their stockroom will be overflowing. The information given to me claims that movement in seventeen directions is possible, I will be most interested to put this through it's paces! A full through port is included and it is claimed to be microdrive compatible, the usual lip at the top of the Interface is there and I would also be interested in trying it for compatibility with one of their superb looking keyboards. PROTOCOL 4 AGF Hardware £30.95 The very latest unit from AGF, this is an interesting looking interface. It lies flat and is programmed by a set of reprogrammable cards which are snapped into place on the interface. The device is supplied with three pre-programmed cards to cover Kempston, Sinclair and Protek/AGF (cursor keys). An extra, blank card is supplied for your own use. This is a great advance on their older interfaces in style and ease of use, however, ZX81 owners will be pleased to know that AGF are to continue producing and selling their old units because, as Mr. Fosberry told me personally, the demand by ZX81 owners is as great as that from Spectrum owners. The unit has a full through port and amazingly, up to five of these can be connected and programmed individually for multiple control! The latest Quickshot II joystick is supported and the socket for the joystick is placed on the side of the unit. Yet another small but useful extra is a reset button to allow you to turn the computer on or off without having to pull the plug each time with the eventual problems this causes. Slightly expensive but for the dedicated games player probably well worth the money. ENDNOTES We covered as many interfaces as we could and I'd like to thank all the companies that sent us review units which allowed us to write a more comprehensive and detailed report. I do realise that as always, these are written by people who are giving their own opinions and you may or may not agree with them. Overall we have tried to give you an idea of what is available but really nothing substitutes for trying them for yourself at your nearest store. There are probably a few companies that we've missed, if they would like to write and tell is, we'll include them in our future features. Each review was written by the person named as the end, if no name appears then it was reviewed by myself - it's a hard life.

Personal Computer News

David Rosam

JOYSTICK JUNKET Programmable joysticks could be the gameplayer's best friend. David Rosam plugs these three into his Spectrum. Finding a joystick interface that lets you play almost any piece of software on your Spectrum is like finding a needle in a haystack. One solution to the problem, for instance, could be a programmable joystick interface. Three new joysticks try to tackle different approaches to programmable interface design. COMCON INTERFACE PRODUCT: Comcon Programmable Joystick Interface MANUFACTURER: Frel Ltd, [redacted] PRICE: £14.95 OUTLETS: Mail order/retail. Most programmable interfaces work by fooling the computer that it is receiving information from the keyboard. This is done by connecting the joystick into the port dedicated to the keyboard. Comcon is by far the easiest to use of the three interfaces, but its construction is a let-down. The unit is large for a Spectrum add-on, needing a fair amount of space behind the machine to accommodate the unit. On top is a dummy keyboard, consisting of rows of two-pronged connectors. Six wires protrude from the rear, (four for the directions and two fire button options) which you simply push onto the desired keys. The crude plastic plugs give the unit something of an amateur air. The unit is compatible with Microdrives, and takes standard Atari-type joysticks. The manufacturer claims that the duplicate edge connector on the unit is suitable for the Currah Microspeech unit, and there's probably no reason why you can't connect any other add-ons. CAMBRIDGE COMPUTING INTELLIGENT JOYSTICK PRODUCT: Cambridge Computing Programmable Joystick MANUFACTURER: Cambridge Computing, [redacted] PRICE: £29.95 OUTLETS: Mail order/retail. Opening the box reveals three components - the interface itself, a joystick and a cassette tape. The interface and cassette are available without the joystick, if you already have an Atari-type joystick. The interface itself is a small black box, about the size of a non-programmable interface, allowing one joystick to be connected. There's also a duplicate edge connector at the rear of the unit so you can connect other add-ons simultaneously. To use the interface, connect the hardware, and then load the tape. Instructions are given as the program runs, so the whole process is quite simple. The package is the most attractively presented of the three, and it's well made, but it's the most expensive. RAINBOW ELECTRONICS INTERFACE PRODUCT: Rainbow Electronics Programmable Joystick Interface MANUFACTURER: Rainbow Electronics, [redacted] PRICE: £25 (inc P&P) (£27 for through-port model) OUTLETS: Mail order/retail. Another small unit allowing the connection of a joystick with a standard Atari-type plug is the Rainbow Electronics interface. And it offers a small loudspeaker to supplement the small noises struggling from beneath the Spectrum. The Spectrum's edge connector is reproduced on the latest model. No extra software is needed to program the interface. Instead, you must press keys, move the joystick, and operate a small switch on the interface, all at the same time. Sounds complicated? - well it is. If you happen to be an octopus it's no problem - otherwise just borrow an extra pair of hands... The speaker on the unit doesn't have good sound quality, and you'd be better off if you disconnect the 'load' wire, and engage 'record' on your tape recorder's speaker. . That way, you also gain control over the volume. VERDICT If you're in the market for a joystick interface, the programmable types are not quite as attractive as they sound on paper. The biggest drawback with most programmable interfaces is that as soon as you turn off the power, they lose their programming. Therefore, before playing any game, you must plod through all the preliminary palaver. This takes time, and can be quite a frustrating process. Personally, I find having to load up a tape or wrestle with three separate pieces of hardware puts me off playing a game in the first place. The Comcon, with its crude connections will allow you to use the same programming day after day. Also, it is much the quickest to program. Unfortunately, the standard of construction is rather worrying, particularly the way in which the wires connect with the plugs. But it's the cheapest of the three and if you're spoilt for choice it's the one to buy.

Cambridge: best looking, but most expensive.

Comcon Interface: the quickest to program.

Rainbow electronics: no extra software needed.

Your Spectrum

Andrew Pennell

STICKING WITH ADJUSTABLES There are now several different ways of hanging a joystick on to the Spectrum, and they fall into two distinct categories - the dedicated type, which uses fixed input/output locations, and the more recent programmable type, which can simulate any chosen keys when the joystick is moved. Andrew Pennell, is concerned with the second variety - devices which should, in theory, offer compatibility with all software. He examines products from AGF Hardware, Cambridge Computing, Downsway and Stonechip. All four of the interfaces looked at allow one joystick (or two in the case of AGF) to be connected to the Spectrum, via the industry standard 9-pin, D-type connector. Any joystick used must be the switched type, and not the proportional variety as used on the BBC Micro, for example. These consist of one switch for each of the four directions, and one for the fire button. Diagonal movement is recognised by two direction switches being activated simultaneously. AGF HARDWARE SOLUTION REC. PRICE: £33.95 PROGRAMMED BY: Hardware COMMENTS: Over-tight connector, rather expensive, somewhat unsightly, works well. AGF was the first company to produce a programmable joystick, and this device remains the only true hardware-programmable interface. It consists of a large, exposed PCB with four ICs and 13 vertical bars. The back of the PCB is covered with black plastic, and for that reason it looks much neater from behind! To program it, two crocodile clips for each direction must be connected to the appropriate bars. A self-adhesive conversion table is supplied to convert each key into the two required connections. A total of ten crocodile clips must be attached, and probably it's best to do this with the power removed. Ten 'programming cards' are included on to which can be recorded the plugging arrangements for your most popular games. When first connected, the interface firmly refused to respond to the fire button on the joystick, no matter how it was programmed. A dismantling of the stick showed nothing wrong, but closer inspection of the interface revealed a truly terrible joint to one of the clips. Swift action with the soldering iron soon had it working. One would hope that the interfaces are tested before dispatch to customers. This exercise brought to light another unredeeming feature of the unit - the edge connector that plugs into the Spectrum is incredibly tight, and almost impossible to remove (faced with the same problem, our editor had to resort to deft use of his letter opener). It's hard to imagine any of this palaver being good for the Spectrum's connector, although removal should not be necessary very often as a carry-through connector is provided to allow any further accessories to be plugged in, piggyback style. AGF actually provides two joystick sockets, but these are connected to each other. The company says that this makes it easier to take part in two-player games, but some may think it's just as easy to pass on a single joystick to the co-player. The sockets are mounted on the top of the unit and therefore the joystick's plug and cable stick straight up in the air - thus easily obscuring one's view of the television screen. However, once the operation had been figured out and the fault corrected, the interface worked very well. Programming is pretty simple and quick, and is of course retained once power is down. A simple demonstration cassette is included but, even so, at £33.95 it does seem a little on the expensive side. CAMBRIDGE INCOMPATIBILITY REC. PRICE: £24.00 (£29.90 with joystick) PROGRAMMED BY: Software COMMENTS: Cannot be used with Microdrive connected, must load tape before use, reasonably priced, works well. The next interface in line was the one from Cambridge Computing, and this comes supplied complete with joystick. It's controlled by software, but requires a program to be loaded from tape first. In fact the program allows a library of data for each game to be stored on the reverse side, so each key pattern has only to be entered once. This does mean though that the tape must be run before play can begin. During the first programming sequence a problem soon became apparent - the whole machine 'hung' with the word 'OK' on the screen. It wouldn't even Break, so all that was left was to pull the plug out. Only after running through this loop again did the truth strike - your reviewer is one of the few to possess both a ZX Interface 1 and a Microdrive, and the Cambridge port uses one of the Microdrive I/O locations. Cambridge really has no excuse for this blunder, the Microdrive ports having been documented since the day the Spectrum was launched - take a look at page 160 of the manual, guys! Interface 1 was removed for the rest of the test and that obviously means that the Cambridge interface will not work with any games that load from Microdrive. Once programmed, however, the joystick interface worked well, with either a normal stick connected, or with Cambridge's own. The latter has a second and independent fire button, which can be programmed to simulate a different key to the first. However, the only game to come to mind that needs two fire buttons is Penetrator. To test the device thoroughly it was used on one of the toughest games for any joystick - Jetpac by Ultimate (your reviewer's normal rig being the Kempston non-programmable interface plus Competition-Pro joystick). Opinions on joysticks are very personal things, and one man's loathing is another man's love. However (to digress a little from interfaces) after playing with the Cambridge stick for some time it seemed to me the device somehow failed to make the grade. It's noisy and not very sensitive and the two fire buttons are quite small (in fact it seemed best to program them both to the same key). The shape of the case looks as if it is designed to be held in one hand and operated with the other, but cramp set in after a while and the only resort seemed to be to rest it on a table instead. The Cambridge interface does have a carry-through edge connector, but if it is incompatible with the Microdrive it is possibly incompatible with most other add-ons too. That aside, it works well, the only hangup being the tape that needs to be loaded before use. It comes reasonably priced at £24.00 for the interface only, or £29.90 if the joystick is bought as well. DOWNSWAY - IN REAL TIME REC. PRICE: £22.95 PROGRAMMED BY: Real-time COMMENTS: Can be re-programmed with game in progress, easy to use and quick to program, very reasonably priced. The Downs way unit is programmed in a very different way to the previous two - namely in 'real time'. There is a 2-way switch on the back of the unit, which is normally in the 'up' position for program mode. To program it, the memory in the interface must first be cleared - which is achieved quite simply by moving the stick to all its positions in turn, and pressing fire each time. This done, each of the eight positions may be programmed by the holding down of the relevant keys and the moving of the joystick to the required positions, each time letting it return to the centre position. The instructions say that the diagonals should be programmed first, but it seemed to me that any order would do, provided the fire button is left until last. A total of nine positions are required, and the diagonals in particular can demand a lot of finger dexterity as you press two keys with one hand and hold the stick exactly diagonal with the other. Once programmed and switched back into the play mode, you're ready to start. However, one great advantage with the device is that the interface can continue to be programmed after a game has been loaded, and therefore any mistakes can be corrected as you go along. The Downsway interface is easy to use, quick to program and also the cheapest, at £22.95. My only quibble is that there should be an indicator label near the programming switch. STONECHIP DEXTERITY REC. PRICE: £24.95 PROGRAMMED BY: Real-time COMMENTS: Affects Spectrum audio and video outputs, complex sequence of programming, can be re-programmed with game in progress, reasonably priced. The final interface to come under scrutiny, by Stonechip, at first glance seems very similar to the Downsway one. It's programmed in the same way, the only apparent difference being that there is a 3-way switch - selecting normal, program or play modes. However, in use it proved to be rather different to the Downsway device. When in program mode, the Spectrum behaves strangely. It makes unusual buzzing sounds, and the border flashes. But the sequence of operations to program it remains the same, although with the one important difference - twice as many operations are required, as the joystick has to have all eight positions programmed once with the fire button pressed and again with it released. As well as taking some time, the task proved not an easy one. To program each diagonal with fire held down requires three keys to be pressed with one hand while the other holds the stick diagonal and presses the fire button. And now, with my teeth... As with the Downsway unit it can be re-programmed after a game has been loaded, to correct any errors - a useful facility. Once all is ready the unit must be switched to the play mode for the joystick to be able simulate the keys. But this in itself presents problems for now you will notice that no keys on the keyboard work, and the ear socket is disabled. That means programs will not load and the switch has to be continually flicked back in order to re- enable the keyboard and thus allow the choosing of options from menus. The Stonechip interface seems to offer similar facilities to the Downsway one, but with several disadvantages to weigh against it. It's also more expensive, at £24.95. MODUS OPERANDI How do they all work? Well, the Spectrum keyboard is based on an eight by five matrix, and was designed to be as simple as possible to read electronically. The AGF interface duplicates the matrix, but instead of having keys on it you can connect each directional switch at a particular point to simulate any key. This is electronically quite easy, but difficult to manufacture because of the matrix connections. The other interfaces are all basically similar to one another, showing just minor differences. They each contain 1K of RAM, not (as normal) in the memory map but in fact in the keyboard I/O space. This enables them to be programmed, ie. have the RAM written to, and then simulate the keys when they are read. The actual method of switching between modes differs widely between the three. Cambridge uses another I/O port as a switch whereas the others just use a switch. The Stonechip design only has three ICs, excluding the RAM chips, but one can't help feeling that too many features have been cut to reduce the chip count. TAKE YOUR PICK In conclusion, it's worth the potential purchaser first deciding whether a cheaper, dedicated interface will suffice. There are three main types, produced by Kempston, Sinclair and AGF. If it will not, then choose the method you wish to use to program it - hardware, software or real-time. My personal view is that the Downsway unit takes the chequered flag, being cheapest and most easy to use. However, the AGF interface may be worth the extra expense for those preferring something that's hardware programmed - even if, as in this case, the result is a little unsightly.

Personal Computer News

Roger Howarth

GIVE IT SOME STICK Now you can use a joystick with any Spectrum game. Roger Howorth reports. Unlike many joystick/interface combinations currently available for the Spectrum, the Cambridge Computing device is software programmable. What this means is that rather than the interface being pre-configured for a certain combination of keys, the Cambridge interface has to be 'programmed' before you can use it. This is easy enough as each interface is supplied with a program that does just that. The advantage of a set-up like this is that you can use this interface with any game (or whatever else), even if the writer made no allowance for the use of joysticks. Interface and software are sold for £24, and the joystick itself costs £7. Together they cost £29.90, it isn't the cheapest of systems, but it's certainly one of the most flexible. If you bought just the interface, you could plug into it any joystick with a standard nine pin 'D' connector. The Cambridge Computing Joystick isn't particularly beautiful - nor is it the easiest of joysticks to use. On the other hand it is cheap to buy, and it features two independent 'fire' buttons. This can make the difference between a joystick being worthwhile or not for some applications. The device is fairly comfortable to hold, which is fortunate as it isn't the sort that can be stuck down with suction cups. The problem with it is that you need to be very precise with the sticks positioning in order to get it to respond correctly; for example, it is easy to think you are moving directly upwards, but in fact be moving in an up/right direction. While on some programs this operator error could be seen and corrected immediately, others, particularly games, may not make this deviation obvious until it's too late (and the galaxy lost). However you can use any Atari-type joystick, so you are not a hostage to your interface if this problem really bothers you. THE INTERFACE The interface is a neat black box that sits on the back of your Spectrum, RAMpack style. However, it is so designed that it doesn't seem susceptible to 'wobble' problems. The only connections present are one nine pin 'D' connector for your joystick and the rear edge connector to hook up to the computer. The interface also has its own rear edge connector which duplicates the Spectrum's and so allows you to use other peripherals at the same time. As with all devices that link into the computer's 'bus', you must only connect or disconnect the interface with the computer turned off. THE SOFTWARE As mentioned in the introduction, the interface is programmable, which of course means you must tell it which keys to emulate, before it and the joystick can be of any use. You could do this directly from the keyboard with a series of 'OUT' commands, or, more simply via the program supplied by Cambridge with every interface. This program is called 'joy' which is ironic, as using it is pretty boring. To be fair, it's not required to be fun, as it is a utility after all. The program is mainly Basic, with a tiny piece of machine code, it's fully menu-driven and is very well error trapped. In fact, it's so well error trapped that you're forever ploughing through 'are you sure' type questions. Naturally, with all this protection, it is impossible to accidentally crash and the program does its job very well, even if it does seem a bit over the top. You can list it, which means it's fairly simple to find out how to program the interface directly from your own programs. Another useful feature of this program is that it keeps a library of the different games that you've used with the interface, so that having programmed the interface once for a particular game (and SAVEd 'joy' with the new library) you need only to tell it to prepare the interface for game X in future. VERDICT This system is slightly more expensive than most, but its advantages are both obvious and real. With systems like this you're not dependent on software suppliers making their games compatible with your joystick - in fact you can just as easily use it with a game, that doesn't use joysticks at all. While it's programmable, the Interface doesn't use up any of your computer's memory as it has its own (1K) RAM built in. The interface seems' reliable and though the Sinclair Interface 2 will probably become the joystick interface standard, and thus theoretically remove the need for a product like this, it will take some time to happen and won't help you with any of your existing software. And, lastly, Cambridge's allowance for two independent fire buttons is a big bonus that few other interfaces offer.