The first rule is: never use the variables controlling loops carelessly, as every variable consumes memory. The variable used for a loop can also be used as a counter, a component in an equation, an array subscript, or part of a conditional expression. Its exit value can be used as a choice or flag in subsequent statements, or it can be used again as the control variable in the next look.

Are you also the victim of the suggestion that a loop may not be jumped into? It may, of course, provided you take care - if you jump in after the FOR you MUST jump out before the relevant NEXT. The best thing is to use the same flag variable for both actions. The following is an example of such a construction. The formula used in line 170 is illustrative only. An explanation of the operation of the routine is also given.

I do realize that I have not covered everything that I could about FOR NEXT statements, but I don't think it is a good idea to go into detail first time round. There will be, therefore, a follow-up series on IF starting with Logical Operators (Boolean Maths) concluding with conversions for statements of the type IF A = B THEN LET C = D, the latter being one of my personal favorites.

2. The IF statement is a very useful one, which few of us are sufficiently skillful to do without. For the programmer, IF is a valuable asset saving time and work. The TI BASIC IF may transfer control to line numbers, whereas under Extended BASIC both THEN and ELSE may contain a string of statements as well, although there are a few which may not be used - FOR NEXT is one. This is logical, considering that any program flow must be able to find its way from the FOR to the NEXT unconditionally. Logical Operators

[XB means Extended Basic. B means TI Basic] XB: Provides 4 logical operators. They are: NOT, XOR, AND, OR. They are available in B but need to be written differently - just remember that -1 is TRUE and 0 is FALSE.

XB: IF NOT X = 1 THEN . . . i. e., if X = 1 is FALSE, then . . .
B: IF (X= 1)= 0 THEN . . .

XB: IF X = 1 XOR Y = 1 THEN . . . i. e., branch if one or the other is TRUE but not both.
B: IF (X= 1)+( Y= 1)=-1 THEN . . .

XB: IF X = 1 AND Y = 1 THEN . . . i. e., branch only when both are TRUE
B: IF (X= 1)+( Y= 1)=-2 THEN . . .

XB: 1F X = 1 OR Y = 1 THEN . . . i. e., branch if either is TRUE
B: IF (X= 1)+( Y= 1) = 0 THEN . . .

X, Y, or 1 may be replaced by any expression. The same goes for relational expressions and arithmetic operators. Be careful though when using multiply and divide and remember that the computed result must comply with your requirements. You can make all kinds of interesting combinations, but test them fully before using them. For example, if you use IF (X = 1) + (Y = 1) + (Z = 1) = - 2 THEN . . . it means that 2 out of the three must be TRUE.

There is another construction in XB: IF X= 1 THEN IF Y= 1 THEN IF Z= 1 THEN 150 ELSE 180 ELSE 260 ELSE 110

To implement this kind of construction in B requires that it be broken down thus:

100 IF X= 1 THEN 110 
101 IF Y= 1 THEN 260 
102 IF Z= 1 THEN 150 ELSE 180 

Note that in the XB line above if the line following is numbered 110 the trailing ELSE can be omitted. Risks With IFs Sometimes bugs can drive you mad and take the fun out of programming entirely. Often the fault lies hidden in an erring IF statement - not even seasoned programmers are immune to this.

Using XB for example, using C = A AND B and IF C THEN . . . is not the same every time as IF A = B THEN . . . When C contains a non-zero value (specifically - 1), this will work, but the result of C = A AND B is not always the same as the result of A AND B in an IF statement.

This problem is caused by Boolean arithmetic and is luckily not one which B programmers can experience.

Soapbox

It is surprising how often you can overlook the most obvious things for the most remarkably long periods of time. Do you realize that it is only recently that I have been reminded that TI are about the only company in the home computer market (which I understand they claim to have created) to leave out a basic essential from its package.

They in fact make it a ridiculously expensive additional item, and it is so fundamental to getting up and started with your 99/ 4A that I am amazed that they have gone for so long without rectifying the omission.

What am I raving about? The cassette cable, of course! It was only when the dealers ran out of them over Christmas (not the only thing they ran out of, thanks to some really creative marketing ploys, presumably originating from the States!) that it was brought home to me - I don't know of another micro-manufacturer in the home market who DOESN'T include all leads with the computer! How about it TI?

Are you going to include the cable in future, or will you reduce its price to a more realistic level, by which I mean a sight less than the GBP10 or thereabouts it currently costs? (GBP 2.50 would be nice if you find that it would actually damage sales to include it for free!

And if you physically can't reduce the cost, will you recommend that the State-side designer( s) be hung drawn and quartered for coming up with such a stupid design?)

While I'm on my usual bandwagon (TI's pricing policy), a recently-joined member has written to me with regard to programming in Assembler, and the cost imposed by TI. I agree totally with everything that this member said (I quote below): there is a growing "awareness" on the part of some recent owners/ users of micros that many of the machines (both business and leisure) are grossly overpriced (compare the fact that a Vic 20 costs more to make than a Vic 64, but the 64 will cost you double the Vic 20's price), and in some cases (guess who?) are deliberately "crippled" in order to restrict their use.

For example, a "dedicated" word processor wastes tremendous amounts of processing power; one which was bought by a University department at my hospital cost GBP 14,000. Literally 3 months after its installation it was superseded by the then new 80 column, 96K PET, (casually described as a "4K toy" by the company rep who sold the WP machine), and at a fraction of the price. To this date the WP manufacturers have refused to release any details of the CPU at the heart of the machine, or to provide any details about, or even facilities for, user-access.

The maintenance contract is stupendous - 15% of cost price, i. e. GBP 2,100 per annum - and the individuals in charge of the machine are victims of the manufacturer-promoted delusion that the machine could have no use other than WP. (The WP software is disk-based, NOT in ROM!) They refuse to press the manufacturers for any further information or facilities.

Can you imagine the furore there would be if someone bought the latest BL estate [refers to a car made by British Leyland], only to find that the rear door had been welded shut, being only for show, that there was no access to the rear storage compartment on the grounds that anything you'd want to carry could fit on the back seat, that the engine had been sleeved from 3000 cc to 800 cc on the grounds that the kind of market at which the vehicle is aimed is one in which the user averages 30 mph and only makes urban trips, and that the bonnet is locked by a special key, which, surprise, surprise, is not given to you and is not publicly-available?

Next year the model will come with a 3000-sleeved-to-1200 cc engine, the rear door-handle will actually turn, but won't open, access to the rear storage compartment is still to be denied the user, but the back seat will be made deeper to take more items, and you get the key to the bonnet [hood] to enable you to do your own maintenance, but the manuals are not provided on the grounds that if you want to maintain the vehicle you will already have done a course in Difficult Mechanical Engineering (run by BL at -500 per day for 3 years). Oh, and you can't get the tools 'cos all the nuts are non-standard, but they are on sale in Outer Mongolia and shipments are expected any day now . . .

And yes, it is cheaper than last year's model, but the petrol [gas] tank has been reduced in capacity as Market Research has shown that the average car driver does 2.3 miles per day, so who needs a 150 mile capacity tank?

This is what our writer had to say: "TI's attitude to making low-level programming freely (well, cheaply!) available leaves a lot to be desired. The full Editor/ Assembler package including peripherals is so ludicrously expensive that only the serious commercial programmer can really be interested. Mini Memory, whilst appearing to meet a need, turns out to be a cynical confidence trick. TI can now say that all the PEEKs and POKEs and "machine code" facilities are available on a plug-in module and thereby deflect a lot of criticism, but to provide only 3/ 4K for programs and give instructions which are inadequate to the point that they assume prior knowledge of Assembly Language programming is quite ridiculous.

Why should TI do this? Well, the answer is there between the lines. TI are obviously interested in selling more and more modules and peripherals. Firstly a better Mini Memory will no doubt follow and be a sufficient improvement to make all the buyers of the present one think about buying another. Secondly, with easy low-level access the market would be flooded the cassette-base user - or third-party-written software which would show that some of TI's modules are not actually all that good. After all, one of the best, TI Invaders, was written by a student in 2 weeks (per Robin Frowd).

There is of course a Catch 22 for TI, because the more cynical owners will start to wait for the "proper" article (at a lower price?) or even buy another computer."

I'd like to underline a couple of points in the above: firstly, when Sinclair's ZX8O came out (which I rejected in favor of the NTSC 99/ 4 which I still have, and which won't be replaced by a PAL 4A until the price comes down to -100 - say Xmas '83), its critics decried it because there was no steady display during processing. Third-party software not only provided that (which Uncle Clive [Sinclair] himself had said was not possible), but also went on to provide arcade-quality games, all through low-level access.

The whole industry which has grown up around providing peripherals for the ZX series has been the making of that particular micro, primarily because of its very deliberate policy of showing-up all the other over-charging manufacturers, and in spite of (incredibly) bad press regarding his company's failure to keep to delivery dates.

If TI could learn anything from that, it should be that you cannot assume that your market will be filled only by what you project it to be. Uncle Clive is putting out another micro shortly - designed not for the home, but for the small businessman. And of course, only small businessmen will buy it, won't they? Will they hell! Every computer enthusiast with the cash at hand (and even those for whom it is not) will be flocking to buy the machine, regardless of what Clive aims it at.

The second point is about the quality of the modules. It is rumored that V110 Extended BASIC (you know, the language that the 99s SHOULD have had first time round) is being re-written, so buyers will be wary of experiencing the same fate as V100 owners.

By the way, did any V100 owners get the module changed for the less-bugged update? I sometimes wonder if ANY market research is carried out before these modules are put on the market (hands up all those retailers who have been overwhelmed with orders for the Physical Fitness module!), and if so, whether the research gets done on Joe Public (who isn't the one to ask) or on existing 99 owners (who are).

I would have thought that the best way of assessing what the market wants now is to get as many responses from existing 99 owners as possible (different responses from each country, no doubt). Oh, look everybody, I've just had an idea! Isn't there a group of people like that, what do they call themselves . . . TIHOME or something, isn't it? Why not ask them? I'm sure they'd be happy to give a list of facilities they'd like, at PRICES they'd like to pay.

Right, that's got that off my chest. On to more interesting things.

Changing Times II

This is the second part of the personal (could it be anything else?) look at the next few years. Because of the broad effect of new technology on just about every aspect of our society, (work, leisure, education, health care, energy use, transport, etc.) it would be impossible to do justice to every topic in just these few pages.

What I will do, therefore, is to pick some of the more general aspects and try to present an extrapolation from today (and the last few years) to some undetermined time in the near future. I have noticed over the past 5 years that the technological advances have outstripped all expectations, while the application of those advances has fallen woefully short of the predictions.

If you disagree entirely/ partly with anything that I may suggest, please write in with your criticisms/ suggestions, together with your reasons for drawing your conclusions, and if there is sufficient response I will publish your ideas. This exercise is designed to set you thinking about the way in which you envisage the future (or the Future as some might have it), and also how you see your role in it.

At the top of the page I have given a short list of example topics, and that seems as good a place as any to begin. If we examine Work, we find that the pattern of work is changing quite rapidly in comparison to say a century or more ago, even though at that time great changes were being seen.

I don't intend to get embroiled in lengthy discussions about the underlying causes of our present economic situation, or about the unemployment problem.

What I will say though, is that I find it ironic that the aim of Trade Unions in this country (and presumably elsewhere) is to reduce the necessity for an individual to work in order to obtain the basic necessities (food, housing, etc.), and yet the ultimate in that condition, unemployment (as we understand it), is still something akin to cancer - you don't mention it in polite conversation, and anyone who has suffered it is isolated and treated differently. If we can't find a tolerant attitude to unemployment now, how could we hope to strive for it in the future?

The late Dr. Christopher Evans said in his Mighty Micro (book and TV series) that if we were going to handle working conditions in the future, we would have to lose the "work ethic" - the belief that an individual is somehow undignified unless he is working, that Man MUST work in order to retain his humanity. This stems from the historic need to work (for the basic necessities, and sometimes not even them), when non-working individuals were a burden on a society which could not afford to support them. The signs now, though, are that we will experience a return to the "slave society" which formed the basis of ancient Roman civilization (and of some more recent cultures, in which Britain played an infamous part).

No doubt the notion of a "slave society" has filled you with misgivings and even immediate dislike; this is because the word "slave" has become synonymous with human captivity.

There are other kinds of slave, though, which you have all been using in increasing amounts over the last century or more, and it has never crossed your mind to think of them as such, I'll bet.

There is one more aspect of this particular topic which would bear more scrutiny, and that is the replacement of humans by machines, often controlled by fewer humans. I'm using a slave now, to produce this Babble. (The machine used to be called a scribe, and it was not an "it", it was human).

On Sunday I'll be using another slave to help me do my laundry - I don't own my own my own slave, I use a group facility called a Launderette. This lunch-time I'll be using yet another slave - this time me - to prepare my meal. There are umpteen different jobs which were formerly done by slaves (sometimes called "domestics", "servants", etc.), and no doubt you can think of many others. Don't miss out the animal slaves either - in particular the horse - when you are making your list.

"Ah, but" . . . I hear you cry, . . . "they're not REAL slaves". Oh, but they are. And machines have been replacing people in many different situations, just as they are going to do in the years to come, and while we think it disgraceful that a robot welder/ sprayer should replace his human counterpart today, 60 years from now they will wonder how any self-respecting human could have undertaken such occupations and retained any kind of dignity.

In ancient times, captured "barbarians" were used as slaves and made to do tasks considered beneath their dignity of ordinary people. In the years to come, machines will take the place of the "barbarians", more so than they have done to date.

I mentioned that work patterns are changing. There is a growth in work from home, especially among housewives and mothers, and this trend will continue.

Mind you, it is only called "work from home"; you don't always have to be at home in order to do it, and anyone who paints a gloomy picture of a house-bound future just hasn't thought things through, or doesn't have all the current advances to hand.

Put together the new flat-screen TVs, high-power batteries, large capacity storage media (microfloppies), and the most recent addition, cellular radio, and it should be obvious that you could be cycling in the Lake District, mountaineering (within reason), lying on the beach at Blackpool or Benidorm [Spain], or lazing on deck in the South Pacific, and STILL be working "from home".

Likewise when it comes to shopping: "interactive television" offers a massive range of opportunities for buying and selling, with cost advantages to both sides.

Manufacturers will no longer have to provide heating, lighting, walking space, etc., in their sales sites (currently called shops or supermarkets) as no-one will need (or want) to trudge around from place to place looking for the best buys (call up your local Consumers Association Best Buy page on Shoptel or whatever), nor will they have to worry about packaging and placement on shelves (a science in itself!), and if this was a fair world, the shopper would feel the benefit by having lower prices - in fact, we will probably see a return to the "delivery van" or its equivalent.

Take things a stage further, with the use of hydroponics (soil-free gardening), and you may not even need Shoptel: your local community will be fully capable of providing just about everything you'd need.

This latter idea of self-sufficiency has political implications - while resources are distributed unevenly throughout a geographical area you need a central government in control (supposedly) of ensuring that distribution is according to need. Remove the need for distribution, and you remove a principal part of the administration required. This will tend to shift the emphasis away from central, and to local, government, and in the years to come, this local government could eventually be far more "local" than it is at present - perhaps something along the lines of the Israeli kibbutzim.

Each "village" or "estate" would then become a political entity separate from its neighbor, but only politically separate, not physically. The likelihood is that travel will fall off (while energy costs soar) until alternative technologies provide the kind of almost science-fiction transport systems which will enable the process of reducing nationalism and prejudice to properly get under way.

Note also the trends evident even now - our requirement for energy (e. g. electricity) is reducing, while our volume of items using energy is actually increasing. Look at the rating for your color TV, and it is probably less than a 150 watt living-room bulb. In two years time, that kind of energy use for flat-screen TVs will probably be halved. (Sinclair's new flat-screen unit uses far less energy and produces such a bright image that there is talk of it being used as a projection unit).

The general trend at present as far as work is concerned is not clear, until you look back a few years and see what has been happening. We are likely to see a reduction in the use of human labor in conditions which are either unhealthy or unsafe. Robot paint sprayers, welders, component assemblers, etc., will replace temporarily those jobs which are not really well suited to the human frame.

I say temporarily because if anything is clear it is that many of those "dirty" or dangerous jobs are going to disappear anyway, as the products they contribute towards will either not exist in their present form, or will cease to be required.

Does this mean that we will see a society of bored, cabbage-like, workless individuals? Only if that is what we want, and I think we'd have to work very hard to achieve such a state!

What will happen is that we will see an increase in the numbers of people being involved in "service" occupations - those where human contact is welcomed or preferred: leisure activities, health care (nursing), social care, and so on. There will also be an emphasis on the Arts, in fact the trend points to the major occupation of the future being self-education and "expression".

Our descendants (provided we don't spoil it all by irradiating everyone!) will most likely be "perpetual students", pursuing their own particular interests for as long as they have that interest. The idea that any study must result in the acquisition of skills useful to society will probably fade away.

If your interest is in 12th century archery then you'll spend time using publicly-accessible data banks to follow that until something else catches your eye. You'll probably also be involved in group field-work (there will be others sharing your interests) which will no doubt involve archaeological work and recovery of archival materials; you won't be wasting your time!

When we look at the field of Leisure Activities, it is possible to see a trend towards hobbies which are more closely-linked to "work" than play (take for example this particular area: microcomputers. Much of the hobbyist's energy is currently being directed at Artificial Intelligence, Robotics, Speech Recognition, (and Synthesis), Graphic Design, etc., etc. These are fields which up until recently belonged solely to research departments in Universities and computer companies), and it looks as though the distinction between "work" and "play" will continue to blur. At the moment there is also an increase in "health awareness", with more and more people taking up activities like jogging and swimming, in fact it seems as though a large section of society has decided to add a little spice to life by incorporating small amounts of sport in their recreational activities.

The TV companies, of course, are doing their level best to reverse this trend by making everyone pig-sick of sport! There seems to be a need to "balance" activities requiring high mental activity and those requiring little or none. If your daytime employment doesn't make a great demand intellectually upon you, you are likely to go for those leisure activities which do, and vice versa. This will probably become more pronounced as time goes by; I certainly don't see, as one gloomy prediction did a few years ago, a society in which lazy, obese, idiot humans have ALL their activity performed for them by robots!

When it comes to Education, things are a little different. This arises partly out of the blurring of borders between education for fun, and education for vocational purposes, and partly because our educational system looks set for a major upheaval. Just recently I was reading a report about the role of adrenalin in learning, and the suggestion seemed to be that raised adrenalin levels could ensure a better retention of information for longer periods of time.

There have also been research projects which have investigated the use of certain gases in increasing an individual's ability to absorb and retain information. The increasing use of micros in schools, and their proliferation in the home, is going to pave the way for a return to the "individual tutor" which used to be the privilege of the well-heeled few; in this case, however, the tutor will not be an ogre, but an electronic friend, who will pace his presentation of information to his pupil according to that pupil's ability to learn.

This is one area in which games are likely to play a very great part indeed - the current presenter of the BBC Computer Program (Making The Most Of Your Micro), one Ian McNaught-Davis, went on record in the first series as a detester of games on micros. This twit said that games were a waste of the processing power of the micro; either he was trying to be controversial, or he is an idiot of the first order.

If you can take a chore like learning (and most kids DO see it that way) and turn it into an enjoyable series of what appear to be games, then more will be absorbed by the pupil, and a genuine enthusiasm for learning will be generated. Not only that, but in the medical field as well games are turning out to have some quite remarkable results: I have heard of cases recently where retarded youngsters have achieved remarkable rates of progress simply through playing the much-maligned Space Invaders.

They were so absorbed in playing the game that they were exercising their weak abilities to make co-ordinated hand-eye movements far in excess of what their otherwise-unstimulated concentration would have allowed under normal physiotherapy.

One young lad whose story caught my eye had been stealing money in order to play on the local Invaders machine. When he was caught there was uproar, and demands to have Invaders banned as dangerously-addictive increased, until someone made the association between the period of time in which the money had been stolen, and a sudden inexplicable increase in the lad's ability to eat unaided, to use the lavatory unaided, and to get dressed unaided. Until then, they had simply assumed that his improved abilities had come about as a result of some unidentifiable factor in his therapy. In fact, if memory serves me correctly, the long-term prognosis for this chap was that he would never learn to perform these simple activities unaided.

This doesn't automatically clear Invaders of any charges, as "normal" youngsters have likewise been found spending huge amounts of money in order to play the game. (If they steal in order to play, that's obviously NOT the machine's fault, but the parents'.) But in no way can games be said to be a waste of a micro's power.

Health care is another field in which technology, especially in the form of micros, is making inroads. Last year I read of a micro application in an Accident department in which brain damage is averted. In the case of a skull fracture, for example as a result of a car accident, there is a risk that fluid can build up within the skull and begin to compress the brain and the blood vessels which supply it, causing damage.

Under the old system, a nurse would check "intra-cranial pressure" every 10 minutes, and if it was increasing, would inject a small amount of a drug to reduce the fluid build-up. Unfortunately with that system, sudden surges in pressure might not be picked up until it was too late.

However, a new micro-controlled system which has been on trial, in parallel with the old system for safety I might add, is able to monitor the pressure every few fractions of a second (if necessary), and inject exactly the right amount of drug to keep the pressure not only within normal range, but constant, which is also of importance. This reduces the dependence of the subject on the vigilance of the nurse, and frees the nurse to perform other duties.

This kind of technology is being used in many disciplines, for example in cases of heart trouble. Just as you can buy a fuel-injection system which has chip-controlled metering of fuel for your car, tailored accurately to the performance of that engine, so you will be able to wear a form of pace-maker which performs a similar function for the heart (in fact, I believe such systems are already undergoing trials).

As our knowledge increases in this field, it would not surprise me to learn that minor surgery will be undertaken by micro-controlled robots (until techniques utilizing Nuclear Magnetic Resonance make surgery largely unnecessary) in super-clean conditions, with anaesthesia being undertaken by another micro. Look out also for genetically-engineered organisms replacing defective hormone-producing organs, making Diabetes a thing of the past for example.

As far as energy use is concerned, I find it a little surprising that few people seem to have realized that there is an overwhelming trend toward lower energy consumption in the years to come.

This is nowhere more evident in the microchip world than in the new science of Photonics, which is the natural successor to Electronics. A new type of chip has been made whose power requirement is so low that there is sufficient energy in a beam of light to keep it going. Science-fiction scenarios in which light-guides will replace wires are possibly more accurate than we think.

On top of that, two other major changes in this field will make differing contributions, whose outcome is not presently clearly defined. The first is the "Biochip", a micro-chip whose components are not impurities in a silicon substrate, but are "etched" onto a protein's surface. The processing abilities (and manufacturing costs) are sufficiently altered to make at least one company predict that it will launch its first product in two years time. Others claim that it can't be done with present technology - but then, that's what they said about Sinclair s products.

The second change is a move away from the two-dimensional structure of today's chips and towards a three-dimensional architecture. I remember a report two or three years ago in which (with typical journalistic sensationalism) it was claimed that the first British 3D chip had been produced and it had astonished technicians by appearing to have "human" qualities. What in fact had happened was that the technology had then been unable to produce the chip without flaws, with the result that signals crossed and gave unpredictable responses.

It's funny that we can talk about a car "sulking" when it won't start on a cold morning, but apply the same anthropomorphism to a micro-chip, and someone's stomach will get gripped by the dreaded cold chills of fear.

You can expect then that the advent of cheap 3D chips in home computers will really take the lid off things. So far I've only heard it discussed with regard to microprocessors, but if it can be applied to memory devices as well, then we could see a massive 64Mbit (64 megabit) chip where currently 256 Kbit leads the field.

Stick eight of those in your micro and you'll have 65536K to play with onboard! All of it using so little power that the electrical potential of your skin would be enough to burn it out.

As far as transport is concerned, there are likely to be several different phases through which we will pass, before the uncovering of new technologies enable us to travel vast distances with little effort. There is an increasing use of micros in the auto industry, one avenue of which could lead to the "driverless" car within a few years.

Apart from the research into cars steered by systems other than the standard steering wheel (begun with an eye to disabled drivers, and now undertaken with a view to reducing the injury risk in the event of an accident), most of the research appears to center at present on anti-skid and anti-locking devices for heavy goods vehicles. These are beginning to filter down to the domestic car, as is the use of directional AI (tracking screens on the dashboard, and even satellite links to determine exact location) which have formerly been the prerogative of military warplanes and some commercial airlines.

As radar systems begin to be incorporated into cars (to warn the driver if he is exceeding the safe proximity between himself and a vehicle in front, and to give warning of unlit hazards on dark roads - pedestrians, parked cars, fallen trees, etc. - together with road surface sensors to give warning of hazards like oil, ice, etc., it is likely that more and more of the vehicle's controls will come under the aegis of a controlling micro.

At present, some heavy vehicles are fitted with a system for use on motorways. If an accident occurs, the police activate a small roadside transmitter which signals each cab as it passes, warning the driver that unless he begins to slow down within a certain time limit, the on-board micro will reduce speed for him, eventually bringing the vehicle to a halt unless over-ridden.

This is an attempt to reduce the degree of motorway pileups due to "motorway madness" where drivers consistently ignored all signs to reduce speed (whether it was poor visibility or actual road signs) and consequently produced horrific crashes. In addition, the on-board micro can be programmed to "cruise" at a given speed, giving the best fuel economy and at the same time avoiding exceeding speed limits.

The logical extension of all this is a network of traffic computers, onto which you would log when embarking on a trip. For those wishing to retain control of their car, the local traffic computer could give you a route to your destination which fulfilled your requirements (much as the AA provide a "direct" or "scenic" route at one time) and which could be varied according to your whims. If you needed to refuel along the way, the on-board computer would warn you, and the local traffic computer could then be interrogated as to the nearest open service station and the quickest route there. If you wanted to depart from the given route, an updated route could be readily provided. On the other hand, a "trained" driver could sit in the driver's position, and let the local traffic and onboard computers handle the whole thing, avoiding stress and strain and more importantly the risk of accident due to fatigue, carelessness, ill-health, etc. As after 6 p. m. the number of accidents involving drunkenness is something like 4 in 6, this kind of control would be highly preferable. With both systems, any build-up of traffic would be sensed by the traffic computer, and cars entering the area would be redirected to less-congested routes.

This system could also function for other vehicles; at present experimental bussing systems abroad are using the bus-stop terminal to obtain information about which potential passengers are waiting where, and wanting to travel to where, so that buses can be routed accordingly.

It is doubtful whether such systems, at least as far as the car is concerned, will be implemented in the near future: I had an argument, with a medic of all people, about the fact that computerized driverless cars remove the control from the human.

The medic argued that no machine should take decisions for a human, and when I asked him about drink drivers, he claimed that all drivers should have the right to drink and drive if they wished. When I pointed out that all victims of such driving had the right to not be victims, he claimed that that was irrelevant. What do you think?

I have noted lately that there is even a strong resistance to computer-aided diagnosis amongst the medical profession. The argument is that the machine might make a mistake and cause someone's death. The obvious answers to that are a) the machine is only an aid, not the final word, and b) fewer deaths would result from an increased efficiency and accuracy in diagnosis.

A recent comparison between a computerized diagnostic system and various levels of medical experience (houseman, senior registrar, and consultant) showed that the computerized system was consistently much more accurate than even the consultant. (I don't have the exact figures to hand, but it goes something like this: accurate diagnosis by - houseman (40 -50%), senior registrar (65%), consultant (75 -85%), micro (95%).

Bearing in mind that this form of computer use, known as Knowledge or Expert Systems, is still in its infancy, I would have thought that anything which improved the chances of being diagnosed correctly first time would be leaped upon by the medical profession, especially as it leaves the doctor free to give more time to his patient (the lack of which many of them lament).

A study in which the diagnostic system was used in psychiatric cases showed that confirmed alcoholics were prepared to confide more in the machine than they were in doctors whom they may have known for many years.

Part of the study showed that an alcoholic would admit to twice the consumption of alcohol to the machine - an intake which the standard system would have to guess existed (for example, if your doctor asks you how many cigarettes you smoke a day, and you say 10, and then he examines your tongue, he'll know that you smoke at least 20 -30 a day; the suggestion is that if the machine had asked you, you would have answered 25).

It seems that patients do not feel that they are being judged by the machine, or that the machine will think any less of them for what they have confided in it. This seems as good a place as any to stop this rambling, as it will never end if I don't cease now! Let me know what you think, and what your alternatives (or further ideas) are. The address is given elsewhere.

Postscript

I also now have a single disk, controller, and manager module, provided by TI through Paul Dicks, so that I can get on with cataloguing the software collection. (I shall not be reviewing the disk system, as it is not a current model, so comparisons would be of no value).

Several things have become evident from the software I have looked at so far: firstly, most authors haven't put ANY details whatsoever with their programs. Not their name, the date, their address, not even whether any special peripherals are needed.

I have had to list every single program in order to find out whether it runs under TI BASIC, Extended BASIC, Enhanced BASIC; whether it needs color or can get by without; whether it needs the Speech Synthesizer, and if so, whether the Speech Editor has to be used or whatever; whether it can run on both a 4 and 4A, or whether it uses the daftly-named "lower-case set", which doesn't give anything intelligible on a 4; whether the output is to disk, cassette, or thermal printer (or anything else for that matter); and so on; sometimes the programs don't do what they say they will (press "Y" for continue, so you press "Y" and the program ends!), or they leave you to contact a medium to try and understand what the program does and how it does it - there are often no instructions.

We have also had collections given us by other groups, and often programs are duplicated because each group keeps passing the same set of programs to new contacts. It won't be long before we start getting our own programs back at that rate! So a word to any new group who wants to swap collections: watch out for the duplicates!

I have also had a couple of articles sent to me which arrived too late to be included in this issue; they will appear next time. They are a report on the Which? Computer Show and Microchips and the Japanese, both by Nigel Clemons. Unfortunately I didn't allow sufficient time to type these up for inclusion, things being rather hectic just now.

For future contributors, Tidings gets put together around the first week of the month of publication, so see if you can get your bits in before then. For those who want to take advantage of my offer to type up their contributions, please send me your items about the second or third week of the month prior to publication, so that I can fit everything in.

Changing Times I

Interestingly, while I was away over Christmas I picked up a copy of the American magazine Byte, and the article by Sol Libes contained much the same set of predictions that CT I had. Great minds think alike . . . ?

I haven't been able to check the directly-available additional characters on the 4A, or to fully investigate the range of keywords in TI BASIC; no doubt someone will have something to add by next issue.

Do we have any teachers or educational users who would like to knock up a page or so of info to keep us all abreast of the times?

Next issue, with any luck, I will review the NEC 30-hour BASIC for those of you who are wondering whether to buy it.

Over the Christmas period I got hit by a hunk of inspiration, and although I have a feeling it won't really be of any use, if there are no takers for the This Is My Only Program In Whom I Am Well-pleased spot, I will present the outline of an idea for a 64/ 80/ any size column word processor for the standard thermal printer. At present I don't have the time to develop it properly, and I have been advised that there are insufficient TPs around for it to be of any real commercial value. If anyone would like to contribute their ideas towards getting it actually up and running, you are welcome.

Well, that about wraps it up for the time being. There are no doubt thousands of things which I have forgotten to say, and even more typos which I haven't picked up, but at least it proves I'm human (but not sane!!).

Enjoy your programming, Pete Brooks.

For example Micro Processor Engineering, Southampton, Personal Computer World, December 1982 p. 197 Source listing + installation manual -19. Mountain View Press in California, Byte, November 1982, p. 365. Fig-FORTH source listing + installation manual $30 total.

Anyone who knows TMS9900 assembly language - can FORTH be implemented this way on the 99/ 4A? Powertran is saying that they are going to implement FORTH on their Cortex computer, which is equipped with a TMS9995 processor.

The Cortex Computer I have read some of the later issues of Electronics Today International (Nov. 1982-Feb. 1983 issues). They are running a construction project, called the Cortex computer. The interesting thing about it is that it is built almost entirely on TI components, as the TMS9995 processor, the TMS4164 64K dynamic RAM, 9929 Video Display Processor and so on. They sell it assembled for GBP 395, kit GBP 295.

The price includes BASIC, called Power Basic, which is also from TI, including PLOT and DRAW commands. I have no idea about how this machine works, but it sounds interesting, especially when you compare the prices with TI's. Anybody who has seen this machine and can compare it with the 99/ 4A? I do not know anything about software for this machine. Peter Brooks.

Ever watched someone rocking a two hundredweight Pac-man T. M. around an arcade? Well these are the very same joysticks that relish that type of punishment.

Designed to be the most substantial joysticks on the market, no consideration at all has been given to looks.

Consider these features before choosing a cheaper unit: Lever operated micro switches: Full eight way operation: Sealed fire button - contacts cannot corrode. Bearings for pivot sealed and packed in industrial grease: So substantial it requires bolts to hold it together: Rivets would burst under the strain place in arcade usage.

ARCADE HARDWARE joysticks are available by mail order from the above address. Please enclose a check/ postal order, payable to ARCADE HARDWARE for -19.50 (this price includes p & p) OR retail from:

Computer Supermarket,    Micro-C, 
Knightsbridge Mall,      Market Centre, 
Arndale Centre,          Manchester. 
Manchester. 

Please note that the price quoted is for single player only.

Notebook
Getting It Taped!
There seems to be quite a bit of discussion lately about the problems of saving and loading programs to/ from cassettes, so I will add my own twopenn'orth for what it's worth. Let me say that, personally I have rarely experienced any difficulty either with my own tapes or with those written by other members.

It seems that, if you have a decent tape-recorder (mine is a Hitachi TRQ 299 which was one of those originally recommended by TI), you should have no problem. One thing that hasn't been mentioned so far in the discussion is the fact that you can get away with murder if you only save and load your own tapes, as any variation in the tape speed (which is the usual source of problems) will be canceled out. For instance I recently had a tape from another member and as soon as the leader tone sounded I knew that it wouldn't load because the machine which had saved the pro-gram was obviously running very slowly with the result that the playback speed on my machine was much too FAST.

By the way, if there is anyone who would like to try a little experiment in the compatibility of data tapes of music, written on the Music Maker Module, I would like to exchange one or two tunes as a trial.

For newcomers to these pages, I will give a short history of the various formats I have been using recently. First of all, in answer to critics, may I say that I have a good typewriter, but I am quite deliberately avoiding using it as I think that, where possible, I should make use of the facilities of the computer, and make it earn its keep, so to speak.

Last month I produced the tiny copy, (which was NOT reduced during the printing), on a SHARP PC 1500 and its plotter/ printer, with varying degrees of success. The main reason for using the SHARP was that I had run out of TP Thermal Paper (why does it always take an age to get anything out of Texas???)

TIHOME Flourishing
With the recent price reductions, there has been (according to Paul) quite an increase in membership. And if the figures on sales quoted in PCS are anything to go by, there have been 20,000 99/ 4As sold in 1982. So far, TIHOME has attracted around 1/ 20th of these owners, so there is a long way to go. I suspect that many people bought the 99/ 4 as a super-duper games machine and have restricted their activities so far to running games modules.

One effect of this has been that I have been having phone calls nearly every night from various parts of the country, usually asking for information. One chap was on the line for nearly 2 HOURS and that was from Huddersfield, (I think). I wouldn't like to pay some of the phone bills!

Paul tells me that he is being inundated with calls also and some of the members who phone me say that Paul's line is very difficult to obtain. I am also getting quite a few letters, usually needing individual replies. I don't mind either the phone calls or letters, but with regard to the latter, I would be glad if at least a STAMP were included (some people do) preferably a stamped-addressed envelope. Also I must apologize for any delays in replying, but I am probably answering the PHONE! If any general queries arise, I will probably answer them through this column, rather than individually.

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