Cheetah Sweet Talker

Your Spectrum

Henry Budgett

SPECTRUM SPEAKERS The word is that attaching any old speech synthesiser to your Spectrum will allow you to have cosy chats together. Henry Budgett determines where this is one of the first signs of madness. For years science Fiction films and futuristic novels have depicted an era when man and machine can communicate in perfect harmony. The reality, of course, is slightly different. While speech recognition has yet to he fully developed (ACT's latest Rascal notwithstanding), chip-based speech synthesis has been both mastered and available for several years. Until recently the computing power needed to produce human-sounding utterances was substantial. Now almost every home computer is capable of being equipped to talk back to its owner at a price that won't even break the average piggy bank. SOUNDING OFF When we speak we produce three distinctly different types of sound. The most obvious are the 'voiced' or vowel-type sounds; oo, ar, ee, and so on. These are produced by air from the lungs making the vocal cords vibrate. The frequency of this vibration determines which vowel sound we hear. The second group is the unvoiced or 'fricative' sounds; ss, sh, t and ff. Here the air from the lungs rushes past the vocal cords without making them vibrate and the frequency produced is controlled by the positioning of the lips and tongue. Finally there's silence or, to be more precise, the minute gaps that occur within words (for example six, eight) where we change from voiced to unvoiced and vice versa. FAKING IT In order to generate speech-like sounds, the electronics designers generally go for one of two methods. The first - and until recently the most common - is synthesis by rule. If the frequencies contained within speech are analysed it's possible to devise a system of rules that allow us to re-create any sound from its basic frequencies. These 'building blocks' of sound are called phonemes and by using them in various combinations any word can be constructed. The individuality of a human speaker tends to be lost when speech is generated like this but the words can be clearly understood. Because the synthesis rules for each phoneme are built into the equipment, the user has simply to supply a list of phonemes to be spoken. It's then possible to generate complete sentences instantly, simply by calling up a string of stored phoneme commands. In reality these phonemes tend to be called allophones; this is because the various building blocks sound different depending on their positioning within a word or phrase. However the principle's much the same. The second method for generating speech relies on the fact that the human ear and brain are very good at filling in gaps. The speech we hear over a telephone line is (British Telecom permitting) perfectly understandable. Yet technically the quality - the range of frequencies we can hear - is only one-fifth of what we'd expect from a standard hi-fi system. We understand what's being said only because our brain does the job of filling in the gaps. With the fall in cost of computer memory it's now possible to convert speech into digital information compressed many hundreds of times by a wonderful mathematical technique called Linear Predictive Coding. The resulting numbers representing the original speech are stored in a ROM. To get any of the stored words out again as speech is easy; we simply give the computer the address in memory of the word and the digital information is recovered and converted back into sound, and because the original speaker's words have been stored, all the personal characteristics remain. That's why Acorn's speech chips for the BBC Micro really do sound like Kenneth Baker. WHAT'S THE USE? The commercial uses for speech synthesis are so many and varied that it's just about impossible to list them all. Looking just at the tip of the iceberg it can be used to replace taped announcements at railway stations and airports; in America it's widely used on the telephone system to inform callers of misdialled numbers and engaged or withdrawn services. Speech synthesis units are also being incorporated into cars like Maestros and Montegos as part of the standard instrumentation so, as well as being something of a sales ploy, they can provide warnings the driver can hear without having to take his or her eyes off the road. A major contribution to road safety perhaps? As far as we are concerned in the home computer and electronic games market, speech synthesis is generally used to enhance games. Scores can be read out and warnings of imminent enemy attack can be given to warn players leaving them free to concentrate on the tactics of the game. Of the five speech units under review here, four of them use the phoneme system and one the stored speech method. Let's take a look at how they succeed in fulfilling their purpose. SUMMARY If you're looking for a means of adding a voice to your Spectrum and of incorporating the facility either into games or just for fun, then the Currah MicroSpeech is almost certainly going to be the best buy for you. It's also got the largest number of games already written for it if you prefer to use shop-bought software. Another of its clear advantages over the other units is the addition of a BEEP amplifier for putting the sound through the TV. For those of you who haven't yet bought a joystick controller or a sound generator and fancy a speech synthesiser at the same time, then the Fuller Box/Orator combination - though expensive - offers the lot in one package. Serious users of speech output have an equally clear-cut choice. The superior quality offered by the DCP S-Pack's Digitalker chips make this the logical buy for anyone using the Spectrum as an annunciator rather than as a games machine. The manuals supplied aren't good enough by far, but the Digitalker chips are more versatile than you might think, so if you buy this one get in touch with National Semiconductor for the real data. Of the remaining two units, the Cheetah offers a built-in amplifier and speaker whereas the Timedata unit doesn't; their respective prices reflect this. Neither of them comes close to the overall 'usableness' of the MicroSpeech and they both lack the BEEP amplifier and keyword voicing. SWEET TALKER Price: £29.75 Cheetah Marketing [redacted] HARDWARE: Based on the by now familiar General Instruments allophone chip, this unit comes housed in a vertical box that measures 100mm by 75mm by 50mm. Offering the benefits of an internal speaker (without volume control) and an expansion bus. Sweet Talker stays pretty much on a par with its rivals in terms of design; although it is well made and very neatly assembled on its single PCB. SOFTWARE: This is the easy bit. Unlike the Currah MicroSpeech where the allophones are built up in strings (which is neat but consumes memory) the Sweet Talker simply uses numbers to generate the allophones. These can be stored as DATA statements ready assembled in word order, or you could build a list in alphabetical order sorted by position within a word. You can generate any of the allophones simply by keying OUT 7,n - where n is the allophone number. MANUAL: It's virtually nonexistent and the meager four sides of A5 give you just the allophone list with some examples of how they would be used and that's about it. The tape includes a short demonstration which, according to the manual, "will explain precisely how to use it." SUMMARY: The quality is as good as any other allophone-based synthesiser and the box does have the space-saving advantage of being vertically mounted. ZXS SPEECH SYNTHESISER Price: £24.99 Timedata [redacted] HARDWARE: Physically this is the smallest of the review units at just 65mm by 70mm by 40mm. Housed in a vertically mounted 'potting' box it offers an expansion bus connector and uses the GI allophone chip. The unit is too small to include a loudspeaker so a 3.5mm jack socket is provided for connection to an external amplifier and speaker. Construction on the single PCB is neat and well thought out. SOFTWARE: Two programs are provided on the accompanying cassette. but the second one - a speech editor from the manual - stubbornly refused to perform, giving 'out of memory' errors when trying to RUN. The cause was an over-dimensioned array, but it's a bug all the same. You can access the allophones direct by using their codes and doing an OUT, or you can make use of the machine code subroutine provided and build strings of allophoncs in the reserved variable s$. In this respect the unit works in much the same way as Currah's MicroSpecch, but without the advantage of having the software built-in. MANUAL: Twenty A5 pages cover the theory and practice of allophone synthesis and example programs are included as well as being supplied on tape. SUMMARY: Although it's the cheapest of the bunch, the lack of an internal amplifier and speaker is a nuisance. With these added it would have been directly comparable to the Cheetah. CURRAH MICR0SPEECH Price: £29.95 Currah Computer Components Ltd [redacted] HARDWARE: Fitted into a neat, flat, black box (75mm by 75mm by 20mm) the unit is certainly designed economically. Just three chips from General Instruments and a handful of resistors and so on are assembled on to a very clean PCB. The standard Spectrum edge connector is fixed horizontally and there's no expansion port. The MicroSpecch will have to be the last unit you fit on the back of your Spectrum, but that's probably a small price to pay. This interesting design puts the Spectrum sound (including any speech) through your TV's loudspeaker - which makes a lot more sense than many of the other methods I've seen. To get the sound out there's one flying lead from the back of the MicroSpeech that goes to the EAR sockct and another for the TV socket. (The new TV socket is fitted to the back of the unit.) You do, however, have to unplug the EAR lead when you want to LOAD a new program; perhaps another socket would have been better. A small 'trimmer' is fitted to allow the TV signal to be tuned in to produce the best combination of sound and picture and once set the MicroSpccch didn't need any further adjustment. MicroSpeech uses the allophone system, with the added advantage that every keyword on the Spectrum can be voiced for you. 'Great for the blind', I thought, but then someone pointed out that it isn't a Braille keyboard... Anyway, you can turn the keyboard voicing off if it gets too much for you. SOFTWARE: The MicroSpeech comes with a cassette that on one side offers a rather silly adventure game that speaks to you, and on the other a demo of the various facilities. Written in Basic, the demo is well worth a look if only to see how the 'professionals' construct their words from the allophone set. When you're driving the device from your own programs the allophone strings are built up in a special string variable which is then automatically spoken. It may save a lot of memory to put the words you want into DATA statements as strings, rather than to store the actual strings themselves. Experimentation here is probably worthwhile if you've got a lot to say! MANUAL: Neat, clear, well presented and very thorough! Need I say more? SUMMARY: If you want to boost your Spectrum's sound output and fancy the idea of a speech synthesiser, then this has to be worth considering. The only possible complaint about it is the fact that it doesn't have an expansion connector. FULLER BOX/ORATOR Price: £56.00 Fuller Micro [redacted] HARDWARE: Designed as much more than just a speech synthesiser, here is a unit that fits right across the back of the Spectrum and measures 235mm by 100mm by 40mm. Because the casing masks all the normal socketry at the rear of the Spectrum most sockets are duplicated on the back of the Fuller Box. I say 'most' because the TV aerial lead isn't; you've got to take the box apart to feed this through. The inside of the box is, to be reasonably polite, a mess! The sound and speech chips are both standard socketed General Instruments devices, but the rest of the construction is a hotchpotch of extra wires and piggy-backed chips. Still, as well as providing sound and speech the fully expanded Fuller Box also provides a BEEP amplifier with volume control, joystick port and an electronically switched LOAD/SAVE system - which means that you don't have to keep on unplugging the EAR lead while saving programs. An extra 3.5mm jack socket has been installed at the back of the unit which isn't explained anywhere in the manual, but it turned out to be an extension speaker socket. SOFTWARE: Activating the speech chip is just a matter of using the OUT statement to pass the relevant allophone number to the Orator. The chip contains 64 standard allophoncs, but quite why Fuller suggest you try a loop from one to 255 is a mystery. Included are two demonstration programs; one covering the Box in general, the second dealing with the Orator. Listing the program is likely to provide rather more information than just listening to it! imagine gets a posthumous plug for its software, some of which works with the Orator, I believe, and all their joystick games are compatible with the joystick system used by the Box. MANUAL: It's the sort of paperwork that looks good at first sight but doesn't really tell you very much. If you want more details on the sound chip itself, try the official GI Data Sheet. The manual's explanation of allophones is quite good but fails to expand into real example. That's why it's a good idea to LIST the demo program. SUMMARY: As an all-in-one unit it's probably quite good for the dedicated games enthusiast who likes the idea of tinkering with sounds and speech. As a speech unit in its own right, it's rather big and clumsy and nearly twice the price of its opposition. S-PACK Price: £29.95 (Extra Word Packs £12.95 each) DCP Microdevelopments [redacted] HARDWARE: Based on the National Semiconductor 'Digitalker' system this was the only review device to use compressed speech. In terms of producing intelligible utterances it wins hands down over all the rest but there are several reservations. It comes housed in a 75mm by 110mm by 45mm plastic box and mounts horizontally behind the Spectrum. In its favour is the provision of an expansion bus connector but, unfortunately, the rest of the construction is fairly low-grade. Inside are two PCBs, one providing the bus and the other the speech synthesis components. An internal speaker is provided along with a 3.5mm jack socket to connect the device to a larger external speaker. The volume control is an edgewise potentiometer, in my view a cheap and nasty approach. The speech chips are all socketed and there's provision for installing four vocabulary ROMs... our review model had all four fitted. When I first tested a Digitalker system some three years ago these were the standard chips. Although the price has fallen dramatically (the experimenter kit was then about £130 with two vocabulary ROMs), the repertoire hasn't. It may be worth contacting National Semiconductor direct to see what else it can offer (UK offices are in Bedford). The speech quality from this unit is excellent. It's easy to hear that the log-on message "This is Digitalkcr" is spoken by an American female and the rest of the words in the first two ROMs are spoken by an American male. I'm also pretty sure that there are two other people speaking on the second pair of ROMs, which is an indication of the sort of information a digitised speech system contains that you don't get from an allophone system. SOFTWARE: Er, there isn't any! You just OUT the required word number to the appropriate port and the device says it. MANUAL: Not a lot of use, I'm afraid. The four A5 sides tell you how to use the thing, but miss out on all sorts of interesting details. Your best move is to get the National Semiconductor data sheets (usually free) and find out from them how to string words together, get parts of words and a whole lot more besides. SUMMARY: For pure speech that's immediately understandable this wins hand down. On the other hand you may want words that aren't in its vocabulary and, as it stands, there's no way to make them. Therefore, it's main use would be in a dedicated system announcing times and other numeric data - it's not much good for games and so on.

The quality is as good as any other allophone-based synthsiser.

SPEAKER COMPARISON CHART Synthsiser: Currah Microspeech Synthesis Type: Allophone Allophone Coding: String Keyword Voicing: Yes Internal Amplifier: Uses TV Internal Speaker: Uses TV BEEP Amplifier: Yes Volume Control: Uses TV Demonstration Tape: Yes Software Provided: In ROM Games Available: Yes PHYSICAL NOTES Size (in mm): 75 by 75 by 28 Format: Horizontal Case Material: Plastic Expansion Bus: No Synthsiser: Fuller Box/Orator Synthesis Type: Allophone Allophone Coding: Numbers Keyword Voicing: No Internal Amplifier:Yes Internal Speaker: Yes BEEP Amplifier: Yes Volume Control: Yes Demonstration Tape: Yes Software Provided: No Games Available: Yes PHYSICAL NOTES Size (in mm): 235 by 100 by 48 Format: Horizontal Case Material: Plastic Expansion Bus: Yes Synthsiser: DCP S-Pack Synthesis Type: Compressed speech Allophone Coding: Numbers Keyword Voicing: No Internal Amplifier: Yes Internal Speaker: Yes BEEP Amplifier: No Volume Control: Yes Demonstration Tape: No Software Provided: No Games Available: No PHYSICAL NOTES Size (in mm): 75 by 110 by 45 Format: Horizontal Case Material: Plastic Expansion Bus: Yes Synthsiser: Timedata ZXS Synthesis Type: Allophone Allophone Coding: String/Numbers Keyword Voicing: No Internal Amplifier: No Internal Speaker: No BEEP Amplifier: No Volume Control: No Demonstration Tape: Yes Software Provided: On tape Games Available: No PHYSICAL NOTES Size (in mm): 65 by 78 by 40 Format: Upright Case Material: Plastic Expansion Bus: Yes Synthsiser: Cheetah Sweet Talker Synthesis Type: Allophone Allophone Coding: Numbers Keyword Voicing: No Internal Amplifier: Yes Internal Speaker: Yes BEEP Amplifier: No Volume Control: No Demonstration Tape: Yes Software Provided: No Games Available: No PHYSICAL NOTES Size (in mm): 110 by 75 by 50 Format: Upright Case Material: Plastic Expansion Bus: Yes

Read it at Your Spectrum Unofficial Archive

ZX Computing

Colin Christmas

TALKBACK: SPEECH UNITS ASSESSED When you find you get to the stage where you find yourself talkiing to your micro, it helps if it answers back! From the time the Daleks trundled across our TV screens muttering "Exterminate, Exterminate" in their chillingly inhuman voice, I have been intrigued by speech synthesizers. At the time of writing, and to the best of my knowledge, there are six different units on the market to enable your micro to answer you back. Two others have recently lost their voice, I asked why, but the suppliers aren't talking. The units on the market at the moment are "Sweet Talker" from Cheetah for both ZX81 and Spectrum, "Micro Speech" from Currah, "Orator" from Fuller, "Vox Box" from Datel Electronics, "Chatterbox" by William Stuart Systems, and "S-Pack" by DCP. I contacted all of the above companies and those units that were supplied for review I sent to different reviewers for their independent comments. For your own assessment here's what they thought.... SWEET TALKER Cheetahsoft Ltd [redacted] £29.95 The SWEET TALKER unit (11 x 7.5 x 3cm) plugs easily and firmly into the user port at the rear of the computer and has its own rear card edge connector for a Ram Pack necessary. A demonstration program cassette is supplied and not only gives a good idea of the range of speech sounds possible but also explains how to program the unit and even gives a few ideas for turning games and original programs into 'talkies'. It takes less than a minute to load. One way to understand how spoken words are formed is to break up the sounds that combine to make a word into allophones, and this unit uses the allophone system to produce words. For instance, the word Cheetah can be broken down to 4 speech sounds or allophones: /CH//IY//TT//AA/. Using the allophone system, each allophone, pause or gap in speech (as at the end of words and sentences) is turned into a number and then given a code. The code is then incorporated within a very simple program using OUT Instruction to 7. An instruction booklet is supplied with the unit and lists the allophones with everyday words which contain examples of the relevant allophones. Find the allophones required by checking through the word lists, then read across to the column listing the Data Codes and enter them in the first statement, followed by four more short lines and RUN. It talks.... There are several bonuses with this system. Firstly, although experimentation is necessary to achieve maximum clarity, it's great fun and often amusing. The booklet is easy to use. Secondly, it teaches the user a lot about the structure of words, vowels, consonants, word endings and so on. Not unlike the use of phonics in the teaching of reading. In this last respect this system could well find a place in classrooms. One word of warning to parents and teachers; the unit will say anything it's told to - and without so much as a blush!! But when will we be able to program our micros to sing "Daisy, Daisy..."?

Sinclair User

SWEET CHATTER FROM CHEETAH The Sweet Talker speech synthesiser from Cheetah has been upgraded so that it will now work with Interface 1 and Microdrives. It uses the popular SP0256 speech chip which contains 64 allophones. An allophone is a sound from which all words are made. They are used by outputting a number to the unit which then 'speaks' the allophone. In that way they can be strung together to form almost any word in, as the demonstration cassette shows, French, German and English. Unfortunately while the PCB has been upgraded the demonstration cassette has not. Users who have an Interface 1 attached will find the computer crashes when the program is RUN. To overcome that edit line 5010 to: OUT 31,a:GOTO 5000. Despite that, the unit worked very well. A volume control would have been an added advantage but you cannot have everything. For more details of the Sweet Talker, price £34.95, contact Cheetah Marketing Ltd, [redacted].

C&VG (Computer & Video Games)

EXTRA BITS Two things which make a micro are hardware and software. Software is the part you can't see - the program, recorded on tape or disk. Hardware is that part that you can see - the computer itself, disk drives, the cassette recorder, a printer. Anything which you plug into your micro to add certain facilities or functions is called a peripheral. In February's C&VG we decided that it was about time we looked at some of the hardware which might interest the games-playing micro-owner. Since then, a lot more add-ons have been released, so we've decided to make Extra Bits a regular feature. You'll find all the latest hardware releases in these pages every three months. Just to prove that we know there's more to the hobby than software. So if there's anything that you think deserves a mention and perhaps a review on these pages, then drop me a line with some details. If you're already in with the communications revolution then you may be a member of Micronet. If so, write to me via Mailbox. My account number is 012 786 556. NOT THE ZX83 A lot has happened for the games player since February. One of the most interesting and closely-watched launches was Sinclair's new micro - the QL. The initials stand for Quantum Leap which sounds like it should mean enormous but, in fact, means quite the reverse. A quantum leap is the smallest possible. Maybe Clive doesn't mean it's a giant leap forward at all. Perhaps he thinks it's only a small step down from, say, an IBM PC which costs many times more. Indeed the free software which comes on microdrive cartridge with the QL will soon be made available to IBM owners, at a cost of around £800. Although Nigel Searle, Sinclair's Managing Director, said at the QL's launch that the machine was aimed at small businesses and not at the games market, many software houses are realising how good a machine the QL will be for writing games on. Its very fast. It has 128K of RAM; enough to store a very large arcade game, and for adventure freaks, the 800k of space available on microdrives could bring some of the traditional adventures out from the massive mainframe computers and onto a home micro for the first time. SPECTRUM INTO QL WILL GO Software house Joe the Lion is currently working on a Spectrum emulator for the QL. This, we're promised, will allow you to load and run Spectrum games on your new QL. The adaptor to handle the cassette input (the QL works only on microdrives) plus the software will cost around £25. MONITOR YOUR SPECTRUM Spectrum owners unhappy with the quality of the display which the machine produces on a normal television can now use a professional monitor, but luxury comes at a price. There are two ways of linking a Spectrum to a monitor. Microvitec, well known maker of display monitors and given much publicity on the BBC's Computer Programme, now has a monitor especially for the Spectrum. And if you think you may ever outgrow your trusty little micro with rubber keyboard, then it'll also fit a QL. It's a standard monitor in a black case to match Sinclair's fairly uninteresting colour scheme. As well as having standard connections for a BBC and QL (which has normal RGB output to drive standard monitors), it is also the first to have the added circuitry inside to accept a connection straight from the Spectrum's edge connector. Although a video signal is available from this connector, it is not in the correct form to be used by a monitor and until now no-one has converted it. The Microvitec product in question is the 1431 and it costs £286, which is around £35 on top of the basic Beeb-only model. This covers the extra chips and things to handle the Spectrum. IT'S A MIRACLE If £35 for a few chips sounds a little expensive to you, then you obviously haven't heard of the Miracle Systems MI3 interface. Its a fairly large black box which you plug into the back of the Spectrum. It then has a socket on the outside to allow a normal RGB monitor to connect to the machine in the same way as the BBC. In effect, this machine has the same circuit as the special Microvitec monitor but fits on the Spectrum directly instead. As an added extra, it also contains a sound amplifier. A volume knob on top is provided to keep the neighbours happy and the box takes all its Power and signals from the edge connector. And so it should - at a cost of just over £70. It's better value to buy the Microvitec monitor and put your ear closer to the machine. Unless of course you already have a monitor. And talking of TVs, the new Sinclair flat screen TV is now available, but still only through mail order. It costs £79 and is a true pocket television. You can run it from a mains adaptor or a special battery. There's no connection for linking it to a computer, although such a facility would be impractical anyway and rather difficult to read. RISING THERMALS Until recently the only printer which would connect straight to a ZX81 or Spectrum without extra hardware was the official Sinclair electrostatic printer. Currently priced at £39, it's still pretty good as value goes. Problem is that it doesn't go very far where print quality is concerned. The paper's also quite expensive and is difficult to write on. Without opting for the expense of a professional dot matrix or daisywheel printer, there is still a happy medium to be found (Russell Grant take note) in thermal printers. These use special paper, but it's treated in a different way. It's a lot thinner, and you can write on it too. Rolls of this thermal paper cost around £l each and, because it's thinner, you get a lot more on a roll. There are two thermal models, distributed by Dean Electronics. Called the Alphacom 42 and 32. they cost £99.95 and £59.95 respectively. The 32 will plug straight into a Spectrum or ZX81 and print the full graphics of the machine. As well as being easier to read than the output from Sinclair's device, it also prints faster. The model 42 comes complete with an interface to link the printer to an Atari, Vic, 64, Dragon or BBC and prints all the graphics. Further interfaces can be plugged in and they cost £25 each. So if you've got a Beeb and a Dragon, you can link them both to the printer for a total of under £125. The Commodore version works with both the Vic and the 64, and even prints cursor control characters properly. A couple more Commodore add-ons have arrived recently. Protek has brought out an interface which will allow you to use any tape recorder with your Vic or 64 - you won't have to fork out for the overpriced Commodore version. This box of tricks cost £9.95, and Protek is based in Edinburgh. TRUE MAGIC Facing imminent launch from Commodore itself is Magic Voice, a speech synthesiser for the 64. It comes as a cartridge but has the expansion slot duplicated on the back, in true Sinclair style, so that you can also plug games in. Some speech systems work on allophone systems. This splits the words up into syllables so that you can produce any word. The Commodore unit only stores whole words, and can hold 235 of them. You can change this list of words if you can digitise your own voice. Commodore will be launching such a system in the summer, called Voicelab, which will let you do just this. No price has been announced for this, but Magic Voice itself costs £49.95. No doubt other software companies will produce games with built -in speech, but Commodore has started the ball rolling with 'Wizard of Wor'. MICRONET HITS 64 Also due out soon for the 64 is a Micronet modem to allow you to link up to the Micronet service. Launch date for the system is mid May, and until then they'll all be hard at work preparing the Commodore 64 database of news, reviews and software. DISK OR MICRODRIVE? Since the launch of the Byte Drive 500 from ITL, you can now buy a true 5.25in floppy disk drive from your local Spectrum dealer. Based around a Shugart drive, the package includes all the necessary interfaces to link to your Spectrum and costs £245. The interface alone, which allows you to use the drive of your choice, costs around £90. However there are a couple of problems with the device. A couple of people have told me that it's rather difficult to use and that the commands are rather complicated - especially in machine code. Slightly more serious is the almost total lack of software released on disk for the Spectrum. This makes the system an ideal buy for a programmer, but not such a bargain for the games player - unless software companies will provide ways of backing up cassette games to disk which is very unlikely in view of recent events. DRIVE WITH CLIVE If exercise is the name of the game, then these two new Spectrum add-ons will interest you. A driving module is now available for the Spectrum, similar in function to the add-on for the ColecoVision. It's a steering wheel contraption which plugs into the Spectrum to add reality to those road race games. The device is produced by Spirit Software which is based in London. I can't tell you anymore about the company as they don't have a phone number at the moment. But if we hear any more news about this product, then you'll be the first to know. Also recently announced is an exercise bike complete with computer interface. The idea seems to be that you use it like a joystick. In your attempts to out-run a Pac-Man, the faster you pedal, the faster you move on screen. Sounds quite clever, really, but rather tiring. After 20 screens of action, your legs'll probably feel a little worse for wear. If you'd like to try your own hand (leg?), then details are from Micro Scope in Maidenhead. HEARING VOICES AGAIN Latest in the line of speech synthesisers to land on my desk is an offering from Cheetah, which comes as a little black box (don't they all) and sits on the user port at the back of a Spectrum. Unlike the Commodore Magic Voice cartridge, this one uses a system of allophones. This means that instead of storing whole words, it stores syllables which you can link together to produce absolutely any word in any language. Although this is harder to program, it is far more versatile and well worth the extra effort. You won't need any software to run the package - it's all on a ROM, so there're no tapes to load. It does come with a cassette demo, though, complete with sample speech in foreign languages, including German and French. And the Scottish one's pretty funny too. Sweet Talker, from Cheetah, costs £29.75. MORE MODEMS Latest news on the modem front is that Minor Miracles has brought out its world standard modem. Although still awaiting approval from British Telecom, the company told me this afternoon that, if the customer wants one, they'll be more than happy to supply it. And at a starting price of around £118, I'm not surprised. But rest assured that the product is well worth the money. It's beautifully made in real plastic, and features all the different baud rate settings. As well as allowing you to link up to Micronet, you can also dial up the various 300 baud bulletin board services which are run in this country. And, if your 'phone bill can stand the pace you can try some of the foreign ones too, The modem will handle all the different rates, leaving you to worry how you're ever going to pay for all those international calls.

Personal Computer News

David Janda

SPECTRUMSPEAK Spectrum speech synthesis: David Janda says it all. PRODUCT: Sweet Talker MANUFACTURER: Cheetah Marketing, [redacted] PRICE: £29.75 inc VAT PRODUCT: DCP Speech pack MANUFACTURER: DCP Developments, [redacted] PRICE: £29.95 inc VAT. (Extra vocabularies £12.95 each.) PRODUCT: Microspeech MANUFACTURER: Currah Computer Components, [redacted] PRICE: £30 inc VAT. The choice of speech units available for the Spectrum is increasing and it's hard to find a magazine without at least one advertisement for something 'new and exciting' in this field. We compared the Cheetah Sweet Talker with two already reviewed, the DCP (Issue 1) and the Currah (Issue 34). Speech synthesisers can be either allophone or digital. Advertisements for the former usually say they'll speak any word you like, but each word must be built up from a set of allophones. In what can be a time-consuming trial and error process. Furthermore, the allophone systems tend to sound like Daleks. Digital speech synthesisers don't sound so bad but neither are they crystal clear. They use words, letters or numbers digitally encoded onto a ROM or ROMS. To get the machine to say something, a number corresponding to a word is sent to the synthesiser, eg 1 = hello. 2 = goodbye,... Since both methods need lots of memory, chunks of the speech unit's memory are transferred in turn, via a buffer in RAM. CURRAH MICROSPEECH Allophone This unit superimposes sound through the TV speaker, which can also be fed into an external tape or Hi-Fi. Pressing any key causes the appropriate letter sound to be spoken. Like the Sweet Talker, it comes with a demo cassette, but its advantage over the Cheetah is that getting it so say something is more natural than sending numbers to a port - with Microspeech you put words into the string S$, enclose the allophones in brackets, and the unit does the rest. Currah's unit still seems to be the best allophone speech synthesiser for the Spectrum, though upgrades on existing models like the Computer Add-ons Speech Unit, will be interesting. DCP SPEECH PACK Digital Digital speech packs can cost up to twice as much as the more conventional allophone equipment, and they have a limited vocabulary. The DCP pack has just 71 entries in its initial directory of numbers, letters, and a few useful words. These are stored in a ROM, and up to three extras can be fitted with more useful words - at a price - to give a total of about 250 words. Accessing the words is simple: when the number corresponding to a word is entered, the word is spoken. This is done with the Spectrum's our command, and the muss: statement gives gaps mid-speech. The unit attaches to the edge connector, and includes a volume control, though you'll need a screwdriver to adjust it. Digital speech is better than the allophone variety and can be further improved by feeding the pack's output to your amplifier from the audio socket provided - adding a little bass can improve the sound dramatically. CHEETAH SWEET TALKER Allophone The Sweet Talker is a small black box which fits onto the edge connector of the Spectrum. A small loudspeaker is housed at the back of the unit, facing away from the user. There are no volume controls, and no means of connecting it to a tape recorder or Hi-Fi, thereby eliminating one way of improving synthesized speech. With the unit you get a demonstration tape and a two-page manual, keeping the package simple, but limiting control. The document contains a list of the 63 allophones available, along with a data number, letter and example for each. They give a good indication of how the allophone will sound, but there are no details about what memory the unit uses or how it uses it, and machine code programmers will need to know this. The unit runs with a rather annoying buzz, which continues as it speaks, adding to the mechanical nature of the sound. However, you get used to this and it's not difficult to get simple sentences spoken. The fact that the sound remains on until switched off means you can add emphasis and lengthen words, though this takes time and a good deal of practice to get it to sound realistic. It is unfortunate, though, that there is no speech editor with the demo tape, which would enable you to bash in sentences which would be translated into codes and then be spoken. This wouldn't need a mammoth piece of code, and it's a pity that Cheetah didn't supply it.

Sinclair User

Stephen Adams

THE INGENUITY OF THE PERIPHERALS MANUFACTURERS HAS CONTINUED AND SINCLAIR RESEARCH FINALLY LAUNCHED THE MICRODRIVE. STEPHEN ADAMS REVIEWS ANOTHER INTERESTING YEAR FOR SINCLAIR USERS. INGENUITY BEATS SPECTRUM LIMITS Stephen Adams summarises the add-ons. The biggest blow to users of non-Sinclair-produced equipment was the announcement of the Spectrum. It knocked most memory-mapped add-ons on the head, as no provision for those devices had been made. That was because, unlike the ZX-81, there was no way of turning-off the internal RAM from the expansion port. The only thing left was for producers to put things in the input/output map or to supply RAM packs or RAM upgrade kits. The I/O map was already full of Sinclair devices, allowing the use of only eight separate devices, if they wanted them to be compatible with the Microdrive. Nevertheless, ingenuity brought forward a large number of new devices after the initial shock had worn off. RAM kits for upgrading the 16K Spectrum to 32K are now readily available for about £21. Fox Electronics, for example, supplies a kit for £20.99 and it has instructions on how to improve your TV display. They are easy to fit and now have simple instructions on what to do, if you can overcome the fear of opening the case. The kits are usually identical to the proposed Sinclair upgrade but will fit only on model 2-type Spectrums. East London Robotics can also supply an extra 64K kit which is paged. For those with a model 1 Spectrum, identified easily by the grey keys, there is the choice of an add-on board made by Downsway Electronics or the Spectrum 32K RAM pack by Cheetah Marketing. The Spectrum RAM pack will also fit on to any other Spectrum, as it plugs into the expansion port. Another memory-mapped device available this year was in a surprising place, inside the Spectrum 16K ROM space. It was the Orme Electronics ROM containing RENUMBER, block delete of Basic lines and many other usefiil routines in a 2K ROM. That can be very useful, as it is immediately available on power-up. Sinclair has also provided new devices in the ROM space, which should please hardware and software users. One is the Microdrive Interface One which not only contains the controlling ULA and hardware to run the RS232/network/highspeed cassette Microdrive but an extra ROM which can be used to write your own Basic commands. The other is the ROM cartridge system available with Interface Two. The RS232 can handle a printer easily with its limited handshaking ability but Still is limited for input from an RS232 device, as all that is under software control and not a hardware chip. The network is a very simple arrangement which allows you to talk between 64 Spectrums but I have no doubt that someone will write similar software to use it with the ZX-81 through the cassette sockets. Two books which should help in this respect are those by Andrew Pennel and Dr Ian Logan. The Pennel one also contains an ON ERROR GOTO machine code routine which should trap 90 percent of Basic errors and send them to a program line to deal with them. Sinclair has also launched the Interface Two, containing two joystick sockets which will operate the first or last set of five number keys. That will mean that software will have to be re-written to use Sinclair joysticks, as the accepted standard at the moment is the one set earlier in the year by the Kempston joystick interface which operates as an I/O device, depending for its decoding on A6 only being low. Much software has already been converted to use it and I cannot see software writers wanting to do it all again. Programmable joysticks are just starting to reach the market, which will eliminate the need to rewrite the software. For the Spectrum and soon the ZX-81, the Stonechip one seems to be best. For ZX-81 and Spectrum users, a cheaper hardware-based version, the Pickard controller, can be used as it fits both computers by plugging into the keyboard sockets. The AGF version uses crocodile clips to set up the five keys to be used; it is a little unstable but it plugs into the edge connector and does not require entering the machine. The Interface Two also has a single ROM socket which allows you to use Sinclair-designed cartridges. It is not known whether software suppliers will want to try to fit normal ROMs to a port like this. That, and the fact that recording Microdrive cartridges is a slow process, will limit the amount of software available from software manufacturers on Sinclair devices. EPROM software for ZX-81s is available from Eprom Services and Audio Computers. Both, however, concentrate on the machine code user and not the games player. The fall in price of the ZX-81 and the amount of hardware available for it has started to attract the business user as a control processor for a robot or controlling some industrial process. That is because it contains all the requirements of the development system on one board - Z-80-A, one of the most popular processors, working at 3.25MHz, TV interface, cassette interface for program storage, alphanumeric keyboard, Basic as well as machine code monitor for designing programs, and an expandable memory map and I/O map. There is also a wide range of machine code assemblers, disassemblers, EPROM cards and blowers, RAM, battery-backed memory already available, costing just a few pounds. That to the industrial process manufacturer is peanuts, as a development kit from a chip manufacturer would cost more than £200 with far fewer facilities. The ZX-81 costs only £45 with a massive 16K memory included. Plain-paper printer interfaces for the Spectrum abound and Tasword, the word processing program, can work with most of them. Hilderbay and Kempston provide software-driven Centronics versions, while Morex provides both RS232 and Centronics outputs. Deans also introduced its version of the Timex printer, which uses a much better paper than the Sinclair, gives a clearer print in both black and blue ink, and will use Sinclair commands to control it, so there is no need for extra software. Printers and other hardware devices make the software "come alive" and that combination makes the Spectrum a very powerful business computer. That is the most important event of the year, as the more software which is written to use the large amount of hardware, the more that hardware will be used. Voice output units, modems - to talk to other users or databases over the telephone - RS232 interfaces and light pens all rely on good software to make use of them. The Cheetah Marketing Sweet Talker, for instance, works better because it is accompanied by an instruction tape which not only demonstrates how to use the unit but also shows the user how to structure programs to make it easier to use in their programs. Modems from Maplin, Ambit and Micronet - for Prestel - will allow users of the Spectrum and, in the first two cases, the ZX-81, to talk to many other computers. Some of them will be other types of computers, like the BBC and the Commodore 64. The others will be maintained by public and private companies which maintain large amounts of information and programs on their computers. Micronet 800 is a database maintained on Prestel computers as a 24-hour-a-day, seven-day-a-week computer club. It has hints and tips on Spectrums - ZX-81s at the moment cannot use the system - as well as news, free programs and a mail box facility. Keyboards and consoles also have been making their presence felt as ZX-81 and Spectrum users want to upgrade their machines. Plastic cases from W H Smith are about the cheapest containers at £3.99 and will take a ZX-81 or Spectrum, as well as a few add-ons. The d'Ktronics keyboard and case or that from Fullers appear to be the most popular but neither will allow the use of the Microdrive interface without taking it out of its case. The Filesixty button set is a cheap alternative for ZX-81 users which gives the advantage of spring-loaded keyboard the same size as that of Sinclair, but without costing more than £10. Colour for the ZX~81 is now available in a simple form for all PAL television users - that is, most of Europe. The black box requires only two wires to insert between the modulator and the breaking of tracks and can be re-connected if required. The rest of the box plugs into the back of the ZX-81 to give black characters on a choice of 16 coloured backgrounds or coloured characters on a black background from DDC. It is also more stable than the Spectrum and requires no extra memory to use it. It will work even on a 1K machine. One device which requires extra memory is the excellent High-res screen - 192 by 256 pixels - and user-definable graphics package made by Nottingdale Technology Centre. It uses the ZX-81 internal 1K RAM for its system variables and 6K of memory for the storage of the screen in the program. No internal wiring is required, as the unit plugs directly on to the back of the ZX-81. For the Spectrum, a unit has appeared which will be of great delight to children and disabled users. It is the Currah microSpeech unit which plugs into the back of the Spectrum and, on command, will speak the key pressed. That happens during program input as well as INPUT and INKEY$. It requires no programming of the speech by the user. Speech output can also be programmed by using S$ to contain the allophones - sounds which make up words - which are then spoken immediately. Thus input and output can be spoken rather than read. Tapes have been causing problems ever since the ZX computers came into existence; the Spectrum is better than the ZX-81 but still can be improved with some extra hardware. Tape filters and switch-controlled SAVE and LOAD devices are available from several firms, like Abacus and Elinca. There have now been three Spectrums produced by Sinclair. The model is, which can be identified by the grey keys or by looking through the expansion interface and seeing an IC socket on the left-hand side; the model 25 have the large, black, ROM chip there. Those Spectrums need their extra 32K of RAM mounted on a printed circuit board before they can be put into the computer. There are no Sinclair RAM boards available for the machine. The model 25 were re-designed completely by a computer and the ULA was changed to get rid of an extra 1C which had to be inserted in the model is, due to a design error. The extra 32K of RAM which can be added to 16K machine now requires only chips to be plugged into sockets on the board. Model 1s and model 2s have had to have an extra transistor fitted to prevent a clash between the keyboard and the ULA TV interface. The latest model 3s have also had their internal circuitry re-arranged and the ULA updated to give a wider tuning range on TV sets. It has also caused some software problems, as the keyboard inputs are no longer held to binary l - + 5 volts - when not in use. That was done to reduce the power 1 requirements of the ULA.

AGF programmable joystick.

Cheetah Sweet Talker.

Microdrive with Interface 1.

Microdrive.

Orme Electronics EPROM read card.

'Printers and other hardware devices make the software come alive.'

Sinclair User

NATURAL SOUNDS BY CHEETAH Cheetah Marketing has produced a speech output device called the Sweet Talker. It is complete in a black plastic box the same size as the 32K RAM pack for the Spectrum. The unit contains a very powerful amplifier and the tape with it not only auto runs to introduce itself but also shows some very good programming practice. The instructions are very simple and the unit should not clash with any joysticks or other items, is it uses I/O port address 7. That may clash with some Sinclair peripherals - the Microdrive, for instance - as Sinclair tends to use only one bit of an address going low to operate equipment and using port 7 takes all the bits from B7 to B3 low. Cheetah is looking into that and may modify the address. Programming is done by using phonetic sounds which allow you to produce the sounds necessary to make up a full word. They are put out as numbers to Sweet Talker in sequence from a DATA statement when you want words spoken. Silences can be included to stop the words or to provide pauses between words - of up to 200ms. The Sweet Talker seems to be about eight to 10 times as slow as others available, which makes it sound more natural. There are ZX-81 and Spectrum versions. Sweet Talker is available from Cheetah Marketing, [redacted]. John Menzies and Boots also stock it. The cost is £34.95.

Read it at Sinclair User Magazine Online