Technical College, Scarborough (1986-88)

We used the following Computers:

• Apple II - for Wordprocessing and Pascal Programming. They had two disk drives.
• PC's - might have been 80'286, I don't remember also with two disk drives. Used for programming COBOL, Dbase III, and Supercalc (Database and Spreadsheet).
• BBC Micro's - for programming assembly language and interfacing to LED's and Buttons. Networked, otherwise they used a tape desk to load info., 64Kbytes of Memory (half ROM), and had lots of games to play on them. Managed to squeeze the whole game of Elite onto it - a Space Simulation Trading Game, showing wire drawn Suns, Planets, Spacestations (very difficult to land on), and rival Spaceships. You could attack another ship for a bounty or it's cargo. But beware Anarchy Systems as they might out gun you, and the Galactic Police.
• Amstrad PC1512 - Alan. M. Sugar Trading - with 512Kbytes of Memory, and Hard Disk Drive (20 or 40Mbytes) and Colour Monitor as optional extras. My Father bought me a PC1512, with a Chess Game and Pascal, but not COBOL (another £70). I opted for two disk drives (330Kbytes) so I was forever changing Disks e.g. Wordstar - MS-DOS (Disk Operating System required at switch on to boot the system - lift you up by your boot straps), Spellchecker, Printer, Data Disk... I also used it to programme Pascal and Quick BASIC programmes - like the Moon going round the Earth and Sun using TRIG; and play Infocom Text Adventures - which are like a book where you play the central character by typing in GO NORTH, UNLOCK DOOR WITH KEY, PICK UP ID CARD... Quite complex for it's time, being much more advanced than 2 word Parsers, and having ZIP algorithms to cram all the Descriptive and AI (Artificial Intelligence) Data onto such small Disks. It had GEM Windows and a mouse as well, but this was useless.
• We also had Dot Matrix and Daisy Wheel (like a type-writer) Printers. With a printer switch to select which computer printed, for sharing.

COBOL a '60's Commercial Orientated Language developed by a Women. Still in use by many banks and businesses. I knew a Women in Wantage who ran a drop in centre who used to programme COBOL. She was offered a great deal of money to fix the millennium bug on old COBOL programmes but declined. Her husband was also a Programmer, she said he spent most of his evening reading manuals. My 2nd year project to write a COBOL programme a system for Scarborough Social Services Disabled Department, which I included a 4 figure year date on. I actually rather stupidly destroyed this programme because I was afraid I would continue spending lots of time working on it being of a perfectionist nature.

Pascal - basically a teaching language. I had only known BASIC so it was quite a change from line numbers, GOSUB's, and GOTO's to procedures (with input, output, and local variables), constants, groups (sets), repeat-until, while-do and loops. I wrote one assignment where you had to work out the leap year. Apparently every 100th year isn't a leap year unless it's 2000, 2400, 2800...

History of the Computer Assignment. Our lecturer gave use a long talk on the History of Computers and then expected us to write an assignment about. Naturally we used most of his material, and he only gave me 40% because he said I had repeated what he said. i.e. Jacquard's Punched Cards, Babbage's Arithmetic Engine, ENIAC, Valves, Transistors, Silicon Chips... I had stayed at my Grandparents during this assignment as I had missed the bus home and asked them to check my spelling, they didn't find any errors, even though the lecturer did. My spelling has since improved thanks to spellcheckers and Email.

Hospital Computer System - me and another student, Nicholas Davis - a bit of a SWAT, friendly with the computer technician - visited the near by hospital to see their computer system for booking people in for appointments on computer and printing it out. I had to deliver a speech about this and was rather scared to do it. I remember getting a laugh though, when I said they have to wait 6 months or until they were dead. In poor taste really.

We had another group visit to Plaxton's Bus Company. Two of my fellow mature students had worked there before going on the course, presumably getting bored of it and wanting a change. One, Mark May, gave me lifts in his Mini. They both went back there after the course, and the other, Stephen Edmons just had to wire up the ventilation system. He often took time off to read the paper in the toilets when he was meant to be working. I known people to do this in another company to.

Mathematics - I was OK at this subject but Mark May beat me. I was used to coming first. Our teacher Mr. Wilson was seconded from the Electrical Engineering Department. One lesson I was the only one who turned up and he taught me a bit about Electrical Engineering. If I had been wise I would have left it at that and not done a Degree in it. I found an interesting book about the history of Mathematics in the Mathematics room. One lesson Mr. Wilson wrote a very long number on the blackboard and said you wouldn't mind the last few digits as your salary. We studied Calculus but I didn't get it then.

Communications - the teacher for this got bullied and refused to teach our other class. We had to do things like hold a conversation on a telephone. I still don't like telephones much except when speaking to someone I know.

Work Placement at Scarbourgh Social Services Disabled Department. I worked on and upgraded programmes on the BBC Micro Computer, mostly games for disabled people. The BBC Micro had 64K of Memory, quite a lot for the time and a very good interface system that they used to connect to 4 big switches mounted on a wooden board allowing disabled people to use computers. I made a new one for them plus a buzzer. I also fixed a automatic page turner for disabled people that the Head of Scarborough Technical College Electronic Department couldn't which used a joystick control. I even had my own office. While I was there every one in my class went to a Computer Fair at Birmingham NEC. I didn't go because I was afraid I looked too young and they would let me in. I also working in a store they had for equipment for the disabled, and helped stock take and wrote a sort programme to do sometime, I forget what, but it worked. I enjoyed Work Experience.

Microprocessor Based Studies using the BBC Micro Computer. There was even a TV Programme called Micro Live that told you how to use the BBC Micro. I programmed in assembler simple things like adding numbers in Binary over 2 Bytes, learned about the Fetch-Execute cycle which is still the core of how a computer works. The speed of a Computer is related to how many instructions it can process driven by the system clock. PIC (Parallel Interface Controller) Microchips still use op-codes, which are just binary commands, each number relating to a different Command. Assembler is just the Binary code written as three letters e.g. ADD known as an op-code. Higher level languages translate their more English like Commands into a number of op-codes using an Assembler which reports errors in the code that would crash the programme.

Three core registers are almost always used:

• The Programme Counter holds the address (binary number) of the current op-code to be read and passed to the control unit. It is then either increments, or changed if the op-code is a JMP (Jump), BRN (Branch on a curtain condition being meet), GOSUB (I know it's BASIC but I can't remember the op-code this is the equivalent, the address of the next op-code is put on the Stack and the programme counter set to the address with the op-code), and RTS (Return from Subroutine where by the top address - First-in-First-Out - is taken from the stack and used to set the Programme Counter). The stack is basically like a stack of plates on a moveable base where by plates can be taken off one at a time in order, or put on in the same manor - this is used to store the Return addresses when subroutines have been completed. Generally the very last byte of memory is used at the base of the Stack, and going backwards and up from there giving an effective infinite of calls with in calls of routines and preventing a crash causing stack overload. The first byte of memory is where the first op-code in the programme is stored, generally, and the P.C. automatically looks there.

• The Status Register contain several flags including:
  • Division by Zero Flag which will basically crash a programme if it is triggered as dividing a number by zero in Mathematics has no meaning.

  • Zero Flag that says whether the Accumulator contains a Zero or not. Used in BEQ (Branch Equal - Assembler Statement), if the computed bit of the IF is Zero the Programmer Counter is set to one address, other wise it jumps somewhere else.

  • Carry Flag used in adding up two one-byte numbers for example, say 150 + 150 equals 300 but the accumulator is only one-byte (8-bits in old computers, 4-bits in the 4040 calculator microprocessor, followed by 8080, 80'186... 80'486, Pentium... Pentium IV - effectively 80'986), maximum 255 (or -128 - 127 using two's compliment for negative numbers). Therefore 300 - 256 leaves 44 to go in the accumulator and sets the Carry Bit which acts as the 256. The A.L.U. contains a Binary Adder that can generate a Carry. You can buy the CMOS 4008 chip to add two 4-bit numbers in binary - I used it to build a circuit that adds two 7-segment display numbers: 0-9, set using toggle wheels to give a result with either 1 on or off followed by another 7-segment display number - it was based in one I has seen in the Science Museum Computer department and worked, I still have mine and there's is probably still one there, as they seldom change their exhibits. The whole school visited it once while at P.C.
    I think it might also be used to hold the result of ROLL-LEFT and ROLL-RIGHT op-codes. ROLL-RIGHT can be used to divide by 2. It is more used to send 8-bit data down a 1-bit line.

  • The Accumulator holds results from the last command processed. The next command possibly using this result. It may me the result of adding two numbers together, a copy of a number looked up in the computer's memory, or a number waiting to be written to memory. Incidentally data for example can come from the keyboard or going to the graphics card which may be a character or pixel (picture element, R-G-B colour code).

  There are three parts to the Microprocessor:

  • A.L.U. (Arithmetic and Logic Unit) - basically a Calculator that can add (subtraction, multiplication, and division can be done by the programme, as can the square-root using Newton-Rabson successive approximation method to home in on the correct number, I wrote a Turbo Pascal (for California) programme (very good for it's time, 1988, can you believe it asks whether you want to use 1.5 Kbytes for Error Messages). The A.L.U. can also AND, NAND, OR, NOR, EOR, and EXNOR. I was very good at Pascal, but it is just a teaching language, it has been expanded to an Object Orientated version, but still not used by Industry. BASIC was another teaching and hobbyist language. Common Industry languages are:
    • Bit-twiddling C used for operating systems and strategy games.
    • COBOL (dated but still in use by the Banking system).
    • ADA (for multi-tasking real time system applications
      
    • FORTRAN (a mathematical language used to pilot space probes)
    • Occam (used to program Transputers which are a mesh of computer microprocessors developed in Britain used to speed computation by working in parallel used mainly for complex Mathematical Computations like predicting the weather and global warming, and C.G.I. (Computer Graphic Imagery – dividing a certain number of light rays between processors to share the share the workload).
    • Java (used for complex applications on the internet like search engines, on-line shopping, credit card transactions...).
    
    
  • Control Unit is where the op-code are recognised and acted on. Data is taken from or written to the Registers, Flags and Memory as necessary.

  • Fast lookup internal Memory and Registers. There are generally about a dozen Registers that can hold numbers and addresses. They are closest to the control unit so are the fastest working Memory. They store the results of computations and look-ups done recently by the programme which may be only part done. External Memory holds the Stack, Programme, Data, contented of the Screen, Keyboard Buffer, Printer Buffer, Modem Buffer, Disk Buffer... Buffers are where data is help in waiting until it is processed. Some devices operate at very much faster speeds than others. For example the keyboard is slow perhaps 80 characters a second, where as the screen needs to be refreshed 60 times a second (power and TV runs at 50 hence the flicker when you see a computer screen on the TV) requiring every pixel (with now generally 65,000 colours) or characters in the old computer with another chip converting characters to pixels. And many in between like a 56k Modem. Interrupts (you can look these up in Windows, sometimes they are required for setting sound cards or modems) are used to prioritorise who goes first (may be 1-16). Each having it's own priority.

One time the College had a break in and half the computers got stolen. After that they fitted special locks to the doors, and it never happened again. Another time I thought I would be clever and type a lecture in on my computer while it was being delivered. The lecturer didn't think much of this idea and made me stop as the typing noise was putting him off.

When in Yorkshire I had walked 30 miles in a day on the odd occasion from Pickering where we had a second house the first belonging to the Church: a Manse to Whitby by the Steam Railway used in the TV programme Heartbeat and alone the moors, by the golf balls: an R.A.F. nuclear early warning system. We got 4 minutes warning in Britain and the Yanks got half a hour. Threads is a good programme about life in Britain after a nuclear attack, When the Wind Blows is also good, a cartoon about a average Joe and his wife tried to follow government warning about fallout, basically storing all the water you can and making a fallout shelter out of your door. Not much use! They have sold off all the Government fall-out shelters where the establishment were going whole-up, dug underground and the entrance disguised as a cottage. My father had his own fall-out suit in his office, I don't know if that was only for officers or whether the squadies got them to. I also walked for Redcar neat Middlesbourgh to Whitby, another 30 Miles; and Scarbourgh to Whitby (through Robin Hood's Bay), 20 Miles. I drank out of a stream and got stomach ache. The families never got them. The Roman Legions used to be able to march 50 Miles in a day, thanks in part to their roads and build a temporary fort or fight a battle at the end of it.

I often went down the sea front while at Tech., particularly Gilly's famous Arcade where I played, among other games (I also ate my sandwiches down there):

• Chopper Lift - I started playing this in America while on a Cruise off Florida. You get a helicopter and have to shoot ships, tanks, mech. inf., etc... and break POW's out of jail and pick them up without killing them and take them back to base. THere were four scenarios: sea and ships; desert; a cave with fireballs which you could hit the roof and die; and another one, I forget. This game was by SEGA and has never been re-released in another format for some reason?
• Gauntlet where you play as the Wizard (Fire Balls and Magic), Elf (Arrows), Warrior (Axes) or Valkyry against Ghosts, Demons, Super Sorcerers, Lobbers and Death in a maze with Generators that have to be destroyed or they make more Monsters. Magic Potions can kill Death which takes 200 life points. I think you started with 2,000 and could get more by adding coins, getting drink or eating food, found about the place, usually next to lots of monsters. You also had to collect keys to open doors. You could skip levels at the beginning by going through a different exit but that usually meant losing food finds. I generally went through all 7 first levels and then hit the random 8th level. You couldn't finish the game as there were a infinite number of levels, effectively. Once I was playing with some friends and went up a narrow passage with one of them behind me and death following him, and I stopped moving so he couldn't get away from death and got killed and turned into a ghost. He was very upset about this, but I thought it was quite funny. We often went for chips with scraps (left over batter).
• Ikari Warrior where to shoot enemy soldiers or get in a tank and blast them. I never finished this is the Arcade but did on my Commodore Amiga.
• Double Dragon you fight a load of thugs and big bosses with you fists or knifes and baseball bats). In the end I could finish it on one 10p.