THE KIDDIES GUIDE TO Z80 ASSEMBLER PROGRAMMING
by D. R. Hunt
The Crossroads of personal computing (it goes on and on).
Part: The Seventh, the last
Putting it all to use.
Making programs do things.
It seems no time at all since I wrote the last episode of Kiddies Guide,
although it’s now early July, so it must be at least six weeks. This episode I have
determined will be the last. It’s taken some eighteen months and roughly 36,000 words
to get this far (36,107 words, I haven’t counted them, but my trusty Spell Guard
program has, that’s including this episode). I feel that it is perhaps time for a
change, and to that end, my (Disk) Pen will be turned elsewhere in future. Thank you
to all those people who wrote me encouraging letters, and thank you to those few who
wrote letters highly critical of my literary style, finding it somewhat jarring on the
nerves. To my critics, I can only reply that the style has been deliberately chatty
with the hope that it might engender some interest in what is after all a very dry
subject. Most people seemed to like it, but perhaps to get some practice at writing on
more serious matters the style of this episode should be toned down somewhat, and the
style made a little more turgid.
So, for this last episode, I have decided to look at the uses of a computer
outside the pure enjoyment of writing software that works or the equally rewarding but
considerably more frustrating task of debugging software that doesn’t. Firstly, it
occurs to me that I haven’t published my philosphical view of what a computer is. How
do I justify my statement that the computer is a remote mental extension of the mind
of the man who programs it ?
Given that the computer is an intelligent machine, in that it may be
preprogrammed (taught) to follow a logical course and make logical decisions based on
the outside factors placed at it’s inputs, it should therefore be possible to adapt
the machine to take command of the outside factors which affect it. Of course I’m not
talking about computers of science fiction which for instance can adjust, say the
weather to suit themselves, or are capable of taking intelligent decisions beyond the
scope of a thinking person. Rather, I am considering the computer from the point of
view that it has somewhat less intelligence than an embryo woodlouse, and is capable
of nothing without being imbued with the intelligence of the person who programs it.
In otherwords, the computer IS the remote extension of the programmer. It can perform
tasks set it by the programmer without supervision. Once set running by some other
person it may perform these tasks without the programmer even being aware that machine
is acting upon his instructions written may be months or years previously. However,
it’s intelligent progress through those tasks has already been predetermined from the
stored image of the logical process of the programmer’s mind in writing the program.
It is incapable of any choice outside the program, and most of all it is incapable of
a single ‘original’ thought.
The machine is, on the other hand extremely fast, and given satisfactory
environmental conditions, meaning freedom from mains glitches, internal faults, etc,
it is infallible. Or, rather, only as fallible as the programmer when the original
program was written. Something outside the scope of the original program can always
occur, and the machine fail to perform satisfactorily. This is not the fault of the
machine, but of the lack of foresight of the programmer in failing to predict the
fault condition. Software failsafe, and automatic learning techniques already exist
for this sort of occurrence, but again, these rely on the programmer to predict that
the unforseen could happen, and for him to endow that machine with the necessary
intelligence to cope with whatever problems might occur. Again the onus is on the
programmer. The machine can not learn from it’s mistakes unless there is a program to
allow it to learn from it’s mistakes, and so on. This type of argument is never
ending, as the next level down is the program to allow the machine to correct the