My first Computer
ZX 81 (1k memory, BASIC, Tape store, B/W TV monitor), 1981
My first computer was a "ZX 81" designed by Clive Sinclair. I purchased
it through mail order back in 1981. It was very small. The key board was only
about 6" by 8", a flat piece of plastic which was at least water proof!
It had an external power supply and it's output fed into a black and white T.V.
Fig.1 ZX 81
The programs were written in BASIC. That is a high level language called Beginners All-purpose Symbolic Instruction Code which was invented in 1964. This code was stored in a Programable Read Only Memory (PROM) chip and remained there when the power was off.
The written programs could be saved to and loaded from an Audio Cassette Recorder using tones to represent the digital code. A suitable program could take up to 5 minutes to load! The computer had space for about 1000 characters of code. This space is referred to as Random Access Memory (RAM) but was lost when the power was turned off.
One program used up all this memory and stopped short when drawing a picture on the screen! Many magazines provided lists of BASIC programs to type in. This was how I learnt how to communicate with my new toy. It was fascinating to discover what the various commands could do. The command line '10 PRINT "Hello" ' would put the word Hello on the screen. The 10 is the first line number. Programs were available on cassette tape. Mostly games.
Memory
Some programs were OK for my 1K memory. Most were written for the 16K add on
memory block which was available. The memory block was not reliable so I built
my own with 8K RAM. Then at least some of the tapes would run when loaded. My
son was about 13 and showed some interest. I was more concerned about teaching
him the multiplication tables which they did not do at school. Many programs
were written to help. Some used simple graphics.
"That's correct Chris!" or "Chris got 8 out of 10 right"
was the simple response.
A program my Dad and I developed was called "Spotting". It simulated
the firing of a gun from a battleship to sink a target on the horizon. "You
are a spotting officer in a battle cruiser circa 1915". You would be told
if you were too long or too short. If too long the angle was reduced. A bit
of fun one Christmas.
Loading programs proved to be a bit tricky ! The volume and tone settings on
the recorder had to be just right. Some times after a 10 minute load the program
would not run. There was no indication of progress until it had finished. You
could only listen to the warbling on the tape and keep your fingers crossed!
A purchased tape program would be timed to the second and if it was too long
you knew it would not fit in the 8k which I had.
By 1983 Clive Sinclair had developed his "Spectrum". A colour T.V. was required to display colour. Several other small companies were getting on the "band wagon".
My next computer
ORIC-1 (16k, BASIC, Tape store, B/W or Colour TV monitor), 1983
ORIC used BASIC like the ZX81 and had a bigger keyboard. It was capable of displaying
colour and produced interesting sounds as well. I kept the B & W T.V. and
used the colour T.V. when running some games on special occasions.
Fig.2 ORIC-1
I continued to type in lots of programs from magazines supplied by the "ORIC" club. They were much more complex. This computer had as much as 16K of memory! It would take several nights to type in a complete program. Still using that tape recorder to 'save' the data, but at least the programs fitted in the memory.
Bugs
When an attempt was made to "RUN" the program they would not work
for one reason or another. These were referred to as software bugs! The origin
of this goes back to the early days of computing. When a computer failed to
work a beetle was found inside and got the blame.
The program was written following a certain "syntax" or structure.
Syntax Errors were most common. Spaces, semicolons, colons and commas all had
significant meaning to the computer. Some listings would use I's and 1's, 0's
and O's which could be confused by the reader.
ORIC had a printer port. I purchased a "Cricket" printer from an
engineer at RACAL. This used thermal paper and enabled me to print out lists.
I was able to find many more errors this way.
I began to realise that some programmers used lots of code to do simple things
while others wrote less but were more effective on the screen.
Having learnt by example I wanted to write some more of my own programs. Computers
are good at remembering and manipulating data. So I wrote programs to store
addresses, household accounts and my family tree.
A game
One popular game was called "Candy Floss". You were required to make
money selling Candy Floss on Blackpool beach. Watch out for the Donkeys which
may eat it all without paying! Jeffrey was often round wanting to play this
game. Mainly words on the screen describing the activity and requiring some
input from the player.
I had got a new tape recorder in the hope that it would improve the loading
of programs. Oric had more memory and so loading took longer to complete. Keep
your fingers crossed!
Something went wrong with the printer one day and the poor old ORIC died. The
power supply went for the chop and killed all the chips inside.
A major improvement
CPC6128 (128k, BASIC, 3 ½" Disks, Colour Monitor), 1986
Along comes Alan Sugar with Amstrad. He was developing the first Personal Computer
clones. Cheap copies of the I.B.M. computer which were popular in industry.
One of his first attempts was the CPC6128. A computer with 128 K of memory.
I could not wait to get my hands on this one & got it from "Robert's" in Hythe. It ran in BASIC but used an operating system called CP/M. This computer came with its own colour monitor. What luxury! The down side was that none of my programs on tape could be used because it used Disks to store the programs. Several disks were supplied and purchased with good games on them. It was a real treat loading them in. So quick easy and reliable. Goodby tape loading for ever !
Fig.3 My 6128
Most of the time I spent typing in new programs from magazines which were available at the Newsagents for this computer as it was popular. This way I became familiar with yet another version of BASIC. I then set about re-typing in all my favourite home made programs. Family Tree, Address Book and Accounts. With a new printer from Dixon's in Southampton I was set-up for some time. Ann did wonder how long that would be!
Words
I started writing letters on my first Word Processor. "Tasword" by
Tasman Software. The words were just about readable on the screen if you set
the colours right. Black on blue paper was what I used then. Cutting, pasting
and page formatting were new to me then. It really encouraged me to write more
and more.
Many problems were encountered while playing with computers. Word Processors
and Printers provided me with more than enough to contend with ! You could get
the words OK on the screen but the printer often had a mind of it's own. Not
only do you have to set-up the page format but also the printer format. Then
you find that some characters would be different on paper !
Computer language originated in America. They use $ and we use £. Now
I hope these are dollars and pounds on this page. American Standard Code for
Information Interchange is used by the computer to represent characters using
numbers. ASCII for short has a lot to answer for here in the UK. The keyboards
had $, £ and a # key. (Dollar, Pound and a Hash key). Now the printer
had a switch which changed the # into a £ (Hash into a pound). So if you
wanted to print a £ you needed to put a # on the screen!
Another problem is related to the page and paper length. My paper is 11" long. (An American size I think). A4 is longer. Question? How many lines to a page. Top and bottom margins. Headers and Footers? Get this lot sorted out and your printer works in synch with the pages you have created. Get it wrong and you can get DOUBLE page breaks, wasted paper or your page cut in half. There are more switches on the printer which turn OFF it's Form Feed and sets the page length. Much determination and head scratching was required to sort this lot out. Some say I have a thin patch on top but I can't see it !
Standard Personal Computers
P.C.2086 (256k, MS DOS, PC, 3" Discs, B/W or Colour Monitor), 1989
Time marches on Computers are getting more popular. The IBM PC is all over the
place in industry. Amstrad has produced their second attempt at copying a PC.
I have a need to get familiar with this beast. I have done a lot with computers so far and I think I know what I need it for. My 6128 uses 3 inch disks. They are becoming expensive and difficult to get hold of. Jeffrey was often round playing games on the old 6128 so it was offered for his use at home. Since then I got to see less of him which I regret.
Fig. 4 Amstrad 2086, 1989
See I can always find a good excuse to change up. Colin North at work can supply an Amstrad P.C. 2086. It looked a good bet coming with Microsoft Windows and other super looking software. With a bit of clever know how on the part of Colin I was able to transfer my programs to the new computer. I used the printer port as the output and fed them into the RS232 input port of the P.C. It was a tricky operation which succeeded to transfer most of the information saved on the 3 1/2" floppy disks which stored 720 Kb.
The computer had colour output but the monitor was Black and White. There was 256K of memory inside. I now have a mouse. My old printer will do for now. This was a big white beast which I needed to tame. Computers were at work now so I needed to understand how to use them.
MS DOS
This machine did not switch on and run BASIC as I have been used to. First it
needed an Operating System. Microsoft provide one called MS DOS. This is a Disk
Operating System which creates files of information that are stored on floppy
disks. There can be a hundred of these files on one disk.
These data files contain text which are either instructions or information.
The computer uses the instructions to perform tasks, like word processing or
playing a game. An information file contains the words that have been written
or a list of names in a family tree. One file could contain say 50 pages of
a document.
There are many "High Level" programming languages which contain the
instructions. BASIC is the one I know and love. Others are more complex and
faster.
WINDOWS
This is a Graphical User Interface (G.U.I.) which enables the USER to run programs
by pointing at pictures, called ICONS, using a mouse. This action converts your
requirements into commands for MS.DOS to carry out.
To start with I was happy till I discovered that Windows would not run properly
without an internal hard drive. In fact I was always having to Boot the beast
from external disks. I was used to feeding software in using disks but there
was more to it now. This is the first of many problems I have encountered while
using this P.C.
Hard Drive
I got a Hard Drive. Much more to learn. The computer had a fan running all the
time which created some noise. None of my computers before made any noise. Now
the hard drive and fan made it just a bit noisy!
All my valuable software is now kept inside on the hard drive. Where to put
it all so I can find it again? DOS to the rescue. It creates "Directories"
or compartments for the files. Each directory can have a name and should contain
all the files needed for a particular task. But the name could only be eight
characters long! It's just like a house with different rooms, a cabinet with
different drawers or a folder with sheets of paper. Up to now all my software
was on separate disks. These will be put in separate directories. The first
directory is referred to as the ROOT. It should contain a few essential files
and a list of directories.
A computer demands 90% input and gives 10% OUTPUT. Compare that with a T.V. which gives 100% OUTPUT.
Start-Up
What happens when the computer gets turned on ? The processor first runs a program
called Basic Input Output System. The BIOS is stored in a special chip called
Read Only Memory (R.O.M.). This program is not lost when the computer is switched
off. After checking it's memory chips and the keyboard it first looks for a
disk in the A: drive. The computer is looking for a BOOT disk or Operating System.
If there is no disk in the drive it will BOOT from the C: drive which is the
hard drive inside. (Some machines have two floppy drives and the second is referred
to as the B: drive). Now that you know this, it is VITAL that you have a BOOT
disk in case the hard drive ever fails. The computer will not know how to work
without it! Keep it safe. I know what trauma it caused me when, one day my computer
failed to wake up.
My boot problem
My first experience of this was one evening the computer did not BOOT or wake
up. It could not find the Operating System! Switch off. Insert your BOOT disk
in the A: drive. Switch on and keep your fingers crossed! It worked OK. and
I was able to continue computing that night. The next time I switched on I held
my breath - it was OK.
The problem returned next time and it needed drastic measures to ensure future
reliability. I made sure that all my valuable software was safely stored on
floppy disks. Then I used a UTILITY program written by NORTON called Speed Disk.
(DOS 6.2 now has a utility called DEFRAG) This checked the entire contents of
the disk and re-wrote its File Allocation Tables. (F.A.T.) It also joined up
all the files which had got "Fragmented". Let me explain. Imagine
a line of words. Rub out a short word and replace it with a longer one. It won't
fit in the space so put in what you can and put the rest somewhere else. The
word has become "fragmented". Now as files are deleted and created
this is what happens to them on the hard disk. The F.A.T. knows where to look
when you load a file. The computer is jumping all over the place looking for
bits of files and putting them back together.
Every now and then run the DOS program called DEFRAG. If you are lucky 9 times out of 10 this cures the problem. I was not lucky. My hard drive was developing "Bad Sectors". The dreaded Lurgy! Help came from Colin. The next drastic step was to re - format the hard drive.
Re - Format
This is what you must do if you ever sell your hard drive. The process will
wipe clean it's entire contents. So make sure you have saved all your files
to external discs. Switch off and put your BOOT disk in the A: drive. Switch
on. At the A: prompt type:- FORMAT C:/S and press Return. The /S puts your version
of the Operating System back on to your hard drive. Now you have the task of
loading in all your programs. Perhaps a bit of housekeeping and planning Directories
should now be considered.
Contents
Every book has a list of contents and is divided up into Chapters. This is how
it must be in your computer on the hard drive. You need to develop a tidy structure
and know where all those valuable programs can be found. It is important to
keep a copy of any new creations outside on a floppy disk.
Clockworks
Now for another problem. I started writing a program to time and count the laps
of model boat races. It required accurate timings of the laps. Hit a key every
time the boat went past. The P.C. contains it's own clock and calendar. But
when I checked the lap times against a stop watch I found that the computer
clock was slow. This problem was never resolved and the month of programming
went down to experience!
If the computer clock was slow you would expect that after a few days the date would be wrong would you not! However every time I switched on, it was correct. After some discussions with Colin I discovered that there are in fact two clocks. One runs on its own and has a battery to keep it going. The other is the DOS clock. When DOS is started at switch on it takes the date and time from the battery clock. My program used the DOS clock. Now remember my pet rodent ? When this was active it slowed down the DOS clock. I have found a real BUG in my computer.
Once again time and developments march on. Magazines have free disks. Software
Junk. I tried one once and found it would not work. Only to discover that the
disk contained twice as much data as my 720 k ones. They are the same size but
recorded using the new 1.4 Mb drives which uses both sides of the floppy disc.
I am using a PC at work now. It runs WINDOWS and I am getting used to Microsoft
Word, a super word processor which I am now using at home.
I considered up grading my system but Amstrad is not compatible with a standard
P.C. I wanted to get a 486 Processor Board but my mouse and keyboard won't work
with it. My dear old 2086 could not even be given more memory. Luckily my new
colour monitor will work with a new processor board or computer.
Another upgrade!
486 DX (4Mb memory, 200Mb hard drive, 1.4Mb floppy disc drive, Colour Monitor), 1994
Colin found a buyer for my old 40 Mb hard drive. I made sure that all the software on the hard drive was copied or available on floppy before wiping it clean using FORMAT. So I saved up and got this new one from Colin. It's got 4 Mb of memory inside (Now 8 Mb) and a 200 Mb hard drive which is the smallest you can get now. The floppy drive is of course 1.4 Mb.
Playing with Windows
The fun starts again. Now with Windows I can explore it's wonders ! But the
hard drive was already ¾ full! So I first got rid of all the wallpaper.
This is a background pattern which you cannot see most of the time any way !
Then I deleted most of the screen savers. These take over the screen when you
stop using the system for more then say 15 minutes ! The screen is cluttered
with little pictures in boxes which you click on with the mouse to run programs.
All very easy. Once you know how to set it all up. More to learn. Everything
now runs like greased lightning !
Add on goodies
One or two extra items must be mentioned. I had got a Teletext adapter for the
6128 which proved to be an interesting feature. I could select all those pages
off air for free. I got an updated version when I changed to a PC. Then I got
a sound card. This could be made to send music to small speakers. Now I have
fitted a CD ROM! These new items were plugged into sockets inside the computer.
Back to the future? 2003
Now it is amazing what you get for your money these days. I now have a lap top
computer. Super fast, high capacity, CD ROM drive etc. etc. Network access is
now taken for granted. It was a Toshiba Satellite A30. Windows XP the ultimate
operating system from Microsoft. Then along came 'Vista' ?