The Tale of Billy the Bit

by Don Johnson

“I’ll show you around, myself,” said the VP. “My name is Victor. May I enquire what your names are?”

  Monty introduced himself and Billy, but felt that it was better not to explain the reason why he was taking Billy to see the CPU. They shook hands formally, before Victor asked them to follow him into a room where there was a quiet hum of activity in the air as a number of VP’s went about their work.

  “This is where the data from the System Bus is initially processed,” he advised. “Part of our complex here is a little like the System Memory, and in this room we decide where each Byte of input data has to go in this local memory area. We give addresses to the Bytes in this local memory that match the positions of each of thousands of points on the monitor screen. The information in each Byte determines whether the point should be dark or bright, and also what colour it should be. When this data gets to the monitor, the way that the colour and brightness of each point is set determines how the picture looks on the monitor. Although the points look quite large to us, they are very tiny to humans, and they just see the overall picture, rather than lots of individual dots.”

  Victor led the way up some stairs, to a room which looked very familiar to Billy, for it was the local memory area, and was organised in a similar fashion to his own home in System Memory. He saw the individual Bits bobbing up and down as data was fed to them by their own ‘Mr Write’, who was busy carrying data from the room downstairs. Their ‘Mr Read’ was taking his data to a room above, but seemed to be reading from a whole row at one time rather than individual Bytes. When Billy asked Victor about this, Victor explained what was going on.

  “Most CRT (Cathode Ray Tube) Monitors are not able to show all the points on their screens at the same time,” said Victor. “They have to show one point after the other along a row across the screen, then drop down and start at the beginning of the next row, and so on. When the bottom of the screen is reached, the whole process starts again from the top.”

  “I see,” said Billy, so you have to send the information for all the points in one row across the screen in a group, and follow it by that for the next row down.”

  “That’s right!” said Victor, who seemed pleased to have a visitor who seemed able to grasp what was going on, “And we add in special signals to show the start of a screenful of information, and the start of each row. They are called ‘sync’ – or synchronisation – pulses, and they help everyone involved to keep track of where we are.”

  “But why do you keep sending the same information over-and-over again,” asked Billy.

  “Because the brightness and colour of the points on the monitor screens fade fairly quickly, so we have to ‘refresh’ them all the time. Sometimes it happens as many as eighty times every second. We do it quite quickly – as far as humans are concerned – so that the points are refreshed before they fade completely, and the humans see an overall picture, rather than a row of dots moving down the screen. Images of things that they see, stay – or persist – for a while in their eyes, and this helps the process.”

  “As you can imagine,” went on Victor, “This takes a lot of organisation, and information is moving around all the time. We have to work with the Drivers for each type of Monitor, to make sure that they can understand and cope with the information that we send out.”

  “Oh! Yes!” said Billy, “I’ve heard about Drivers before, but I suppose that you work with different types than those on the Keyboard and Soundboard.”

  “True!” said Victor, “But we shall soon have to get used to working with new types of Drivers, and re-organising the whole way we work. There are new types of Monitors being used with systems now, called TFT LCD’s. That stands for ‘Thick Film Transistor Liquid Crystal Displays’, and they can show all the points on a picture at the same time. We only have to send information about points which change their colour or brightness, rather than having to send information for all the points over-and over. As far as the humans are concerned, they are better, as they get no flickering at all, and they like these new screens because they are slimmer than the CRT versions. We are really going to have to make lots of organisational changes here to be able to cope with these new Monitors though, and I must say that I’m not looking forward to it. Still, that’s enough about my worries, let’s go and look at some of the test screens that we have here and see some of the images that we show.”

  Victor then led Monty and Billy on a tour through more of the rooms in the Video Card, and they looked at lots of different types of pictures on the test screens. Some of the things that they saw could not be understood by Monty, let alone Billy, with strange sights, animals and moving patterns that dazzled their eyes. When they asked Victor about some of the more strange scenes, he replied that that it was impossible to understand everything that humans do, their world was so large and varied that it was largely incomprehensible to computer-dwellers.

  “We have to assume that the information we are dealing with makes some sense to them,” declared Victor, “But I have to admit that it often leaves me baffled!”

  At the end of the tour, Billy and Monty thanked Victor for his kindness, but he waved aside their thanks, saying that it was stimulating to talk to those who showed a real interest, and were not just doing the ‘grand tour’. He gave Billy and Monty a pen each, which were engraved with the name of his company – ‘Matrox Millenium’ – and which he said could be momentoes of their visit. After shaking hands again, and with more thanks, Billy and Monty left Victor at the door of the building and made their way back to the System Bus.

  “What a nice chap.” said Billy when they were out of earshot. “He really made us welcome.”

  “Yes,” replied Monty, “But mentioning the CPU certainly helped. Talking of whom, we had better get a move on, or we shall never get there. Luckily it’s not far now, so we can probably walk the rest of the way. Come on – the last one there’s a cissy!”

  Chapter 7 Up to no good!

  Monty raced Billy to the comer of the Video Card building. Despite Monty having started before Billy had realised he was being challenged, Billy was determined not to be beaten, and they arrived together. They rounded the corner, and as they stood there, each catching his breath, Billy could now see several more buildings. In the distance was a very large, square structure, with lots of metalwork on top, but nearby were four smaller, long rectangular buildings, three of which had cables emerging from their roofs.

  "More Component connections?" enquired Billy, pointing at the nearby buildings.

  "Yes," replied Monty, 'These are for the Hard Disk, CD ROM and Floppy Disks."

  "That's only three," said Billy, "why is there one more building?"

  "It's to cater for expansion - if the System needs another Hard Disk, it can be linked to the empty building," answered Monty.

  "You talk about Hard Disks, and Floppy Disks," said Billy, "But what are they, and what is the difference between them?"

  "Both types of Disks are for storing information on a long-tem basis." responded Monty. "In the System Memory area where you live, information - or data - is stored on a more temporary basis, and is concerned with tasks that the CPU is actually dealing with at any time. On the Disks, data for use in tasks, or the instructions for actually performing tasks themselves, is stored there more permanently. Because there is much more data on the disks, it has to be stored in a very organised manner, and it is usually extracted again in large chunks, in the same organised way as it is put in."

  "Why are two types of storage needed," asked Billy.

  "It's all to do with how quickly things can be done," said Monty. "The information that you store, is needed very quickly so that a task is not delayed, and it could be from anywhere in System Memory. Because data can be taken from anywhere, this type of memory is known as Random Access Memory - or RAM. Disk memory access is not random, and is much slower because data is stored and retrieved in an organised way, and this takes more time. So
it is used for data that is not needed so quickly, or is just too large to store permanently in System Memory."

  "O.K., I think I understand," said Billy, "But why Hard and Floppy?"

  "In the early days", replied Monty, "Removeable disks were made of thin plastic, and were very flexible - or floppy! Nowadays they are protected by a thicker, fairly rigid plastic cover, so they are no longer really floppy, but the name has stuck. On the other hand, hard disk units are usually permanently fixed in the system, and the disks themselves are made from metal, with several of them are housed together in a sealed metal container. As a distinction from the smaller, removable types, these have become called 'hard' disks."

  "Oh! I see!" said Billy. "You know, when you first mentioned Hard Disks during the first part of our trip, I did wonder if there would be 'soft' ones. I suppose that 'floppy' is just another way of saying the same thing. I do want to ask you about the CD ROM, but before you tell me about that could we take a look inside a hard disk?" he enquired, hopefully.

  "Well, I suppose so," said Monty, "It shouldn't take long, but it depends whether I can arrange it. Let's get up on the roof and see."

  There was a staircase at the side of the middle building, with only a short climb to the top. When they emerged onto the roof Billy could see that there were Drivers running up and down the building's cable, and Monty went over to talk to one who seemed to be supervising the others. Billy remembered that the Drivers carried information backwards and forwards for the Components outside the System, and guessed that the Disks must need the same sort of translation service. It was difficult to say why, but the Drivers certainly did look 'foreign' in some way - they were somehow 'different', but Monty seemed to be having no difficulty in making himself understood.

  "The supervisor owed me a favour from when I helped him with some translation difficulties at the time his group first arrived," said Monty as he called Billy over. "And he has agreed that we can go up to the Hard Disk."

  Billy watched the supervisor walk over to a storage shed, and return with a couple of sets of straps, joined together with metal clips and clasps.

  "Zese are ze zafety 'arnesses," he said in a heavily accented voice. "Ze Rule iz zat you must wear zem!"

  The supervisor helped Monty and Billy put the harnesses on, and fastened them tightly around their legs and waists, completing the job with a clip through a central pin. He led them over to the base of the cable, and stopped two of the other Drivers who were about to climb up, by tapping them on their shoulders. There was some conversation between the three, and Billy heard some comments about "Bonuz" and "Ze overtime", but eventually agreement seemed to be reached. There was a large quick-release buckle on the front of Billy's harness, and the supervisor attached this to a ring on the back of a similar harness that the nearest Driver was wearing. He then repeated the process for Monty and the other Driver.

  At first Billy though that he and Monty were just going to dangle below their respective drivers, but the supervisor gestured that they should climb on the backs of the Drivers, and hold onto their harness - just as though they were being given a piggy-back. This they did, and without any further ado, the Drivers set off up the cable, not appearing to be affected by the extra weight of their passengers.

  As they climbed, Billy could see that the Drivers had very strong arms and legs, both of which ended in very strange 'hands'. Each only had one wide 'finger' and an equally wide 'thumb'. In the short moments when their 'hands' were taking a fresh grip, Billy saw that the inner surfaces were covered with ridges, which obviously helped them to get a very tight grip on the cable, and prevented them slipping. After they had climbed for a while, Billy took a look down, and then wished he had not! They were now very high above the building, and Billy shuddered at the though of falling all the way down. He quickly looked upwards again, and reassured himself that the Drivers obviously did this sort of thing all the time, and the safety harness appeared very strong and in good condition. Nevertheless, he was very glad when they reached to top of their climb, and entered a large metal enclosure through a window over the top of the cable attachment point. After they had unclipped, and removed their harnesses, Monty invited Billy to come back to the window, to take a look at the 'splendid view', but Billy declined the offer. He assured himself that he was not realty frightened of heights, but he had seen quite enough on the way up!

  Monty thanked the Drivers, then led Billy to a door with a lever and a spoked wheel on its front. He moved the lever, then spun the wheel, before trying to open the door. He needed Billy's help with this, for the door was thick and heavy, and had rubber seals around the edge that became visible as it opened. Through the doorway, they entered a small room, which only appeared large enough to contain three or four people. It was featureless, apart from a control panel on one wall, and a similar door to the one by which they had entered, on the other side. Monty got Billy to help him pull the door shut again, and then reversed his actions with the wheel and lever. When the door was firmly secured, Monty moved to the control panel on one wall, and pressed three buttons in turn. A red light appeared, and there was a hissing noise. Billy felt his ears 'pop' as the pressure of the air in the room changed. The red light on the control panel went off, and a green one came on. Monty pressed another button on the control panel, and a part of the plain wall swung open, revealing clothes hanging on pegs.

  Monty handed Billy an all-in-one suit which was made of a transparent material, and which had boots and gloves joined to the ends of the legs and arms. Following Monty's example, Billy put his suit on, pulling a hood which sealed around his face over his head. They helped each other doing up long double-seal zips at the fronts of their suits, then stood there looking at each other solemnly. This did not last for long, however, as Billy - and then Monty - burst out laughing at the funny sights that they presented.

  "What is all this about," gasped Billy, as he tried to stop laughing. "Why are we dressed in such a peculiar fashion, and what's this room?"

  "This 'room' is an airlock," replied Monty when he had regained control of himself. "And the suits and the airlock are to protect the very clean area where the Disks are. The slightest amount of dust or dirt that got inside could cause terrible damage, so precautions have to be taken against anything unwanted entering. You'll see why in a moment."

  He moved to the other door, and they went through the procedure with the lever and wheel to open the door, finally emerging into a very large brightly-lit area. It was spotless! The walls were gleaming metal, and there was not a speck of dust to be seen. In the middle of the room were a number of large shiny round metal disks, spinning on a central spindle. Despite their large size, there was no vibration due to the spinning, nor any noise. There was just a quiet hum in the background, probably from whatever was keeping the disks going round. Each disk had an arm mounted above it. The arms could turn on a separate spindle, so that the inner ends of the arms could move in arcs over the disks. Billy bent down to look under the lowest arm, at the tiny gap between its inner end and the surface of the disk.

  "What's holding the arm up?" asked Billy, for there seemed to be nothing to stop the end of the arm from dropping onto the disk.

  "Air!" said Monty. "The gap is so small, and the surface of the disk and the arm end are so flat, that the arm end floats on a cushion of air. Now you know why no dirt or dust is allowed in here. A particle of dust would be enormous compared with that tiny gap, and if it became trapped beside the end of the arm, it would scratch and damage the flat surface of the disk, and prevent the arm’s ends from floating. Even the mark left by a human's finger would jam the arm end onto the disk, and ruin the surface."

  (Billy and Monty could see the gap between the arm and the disk quite clearly, for to them it appeared small, but not that small. It has already been mentioned that those who dwell inside computer systems live at a much faster rate than humans, but it should also be remembered that they are extremely tiny! It would be very
hard for a human to see a computer-dweller, and even more difficult for a human to see the gap that Billy and Monty were examining so easily.)

  Just then the arm just above the one that they were looking at started to move. It swung to a new position, nearer to the inside of the disk, and the end started to glow. Monty took the metal cylinder of his IRQ kit from his pocket and tapped the end on the floor to extend it. Holding it tightly so that it could not be pulled from his grasp, he demonstrated to Billy, that the end was alternately attracted to, and repelled from, then end of the glowing arm.

  "That's magnetism, that is!" declared Monty. The force that makes some things attract iron and steel, and which makes compasses work. The surface of die disk is being magnetised in some spots and not in others as the disk spins under the arm. Where the disk is magnetised represents a one and where it is not represents a zero - much like you standing up and down in System Memory."

  "How clever!" said Billy. "Does the magnetism last for a long time?"

  "Ages!", declared Monty, "And at any time, its state can be read by a same part on the end of arm that puts the magnetism there in the first place. Instead of the rows of memory that are familiar to you, the data here is stored in rings, or tracks, and there are thousands of separate tracks side-by-side all over the surface of each disk. There's a control room nearby, where the organisation of the data is controlled by the equivalent of your Mr Read and Mr Write. The data they deal with is carried backwards and forwards by the Drivers who gave us a lift up here, as it goes to and from the System Bus and the CPU.”