 The magazine of the Melbourne PC User Group A Beginner's Tale: Part 20 Ron Wilby |
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Some laughs this month, as usual at Ron's expense, and some surprises too. Would you believe, Ron gives in! Also, computers being trained instead of their users!
Ron Cracks at Last
Yes, I've given in at last. The pressures of new technology were too much for me. This week I bought Windows, a mouse and OS/2. Why Windows and of course the mouse? There is just too much good software now being released which runs only under Windows. Everyone from our letter box to our user group has Windows only software. If you want to use that software, you buy Windows! And why OS/2? Because it's a cheap (I hope) upgrade path into later and better versions of OS/2. I haven't installed it yet, have to write this first. No doubt there'll be lots of comments from me when I do.
Another Mishap
What I bought was called "Microsoft Power Pack" and there was another of those Microsoft Mishaps here. Easy registration, the brochure said. Send us the registration card and then when you need product support, just call this (Sydney) number and hang on for ever. When someone answers, the brochure said, just quote the six-figure number printed on the reverse side of this page. This validates your Service Guarantee and is unique to you, so keep it safe. Yes, you guessed it, there were some numbers there, but no six-figure number. Oh, and incidentally, I got another copy of DOS 6.2. Would anyone make an offer?
It's all as I've written before about upgrades. The promise of keeping our PCs on the cutting edge of technology, of more goodies to play with and smooth interaction with our other applications was too much. All this, plus being one of the first to try out those 99 new features, causes the credit card to leap out onto the desk in front of you and the dialling finger to start shaking in anticipation.
No-Hands News
Many of you are going to laugh at this, but one day you won't. Hands Free personal computing is here at an "affordable" price. Depends how you define "affordable." IBM's Personal Dictation System, reported available at less than $4000 (why do they always say that, we know it means $3999?), has arrived. This system can analyse your spoken words and use them in word-processing and spreadsheet applications. Osborne Computers Australia has a more advanced version using its Gold Series DX2/66, priced at $9995 (ten grand to you). You need a two hour training session, but there's a difference. The computer is being trained!?
After that, any person can issue verbal commands, dictate letters etc. at speeds up to seventy words per minute. You can have as many users as you wish, 4 MB of disk space being needed for each one.
Whatever happened to those lovely shorthand typists who brightened my days?
Feel Like a Nibble?
There has been a lot said about bits and baud with the recent excitement over high-speed modems. When I was lecturing at Uni, I explained the difference this way.
Any digital transmission is divided into a succession of time segments. A different signal (pulse) can occupy each of these time segments.
These pulses can have various values, which is how the information is sent. In binary transmission, the pulse values are 0 or 1 (off or on, high or low, true or false). Just two possible states.
Right, you say, to transmit faster we send more symbols per second. Wrong! We are transmitting over a telephone line, basically designed for voice transmission at frequencies up to about 3000 kHz. Modems and their digital signals are intruders into that analogue world. Many and ingenious are the methods used to overcome the telephone line's limitations, but still it effectively limits the symbol transmission rate. Of course, special lines are available, at high cost, but most of us use the ordinary telephone lines which Telecom provides to link us to the nearest exchange. So how to speed up transmission?
Getting Up Speed
Other systems can use more than two states. Voltage levels, frequency and phase can be varied so that each symbol can have perhaps 16 or 32 possible states. The information content of any particular time segment is defined as log2 (log to the base 2) of the number of possible states the pulse can have. For binary pulses, two possible states, log2 of 2 is just one. Thus, a binary pulse transmits just one bit of information. Then the rate of transmission is x bits per second or x binary pulses per second. Now, to push up the transmission speed, suppose we have pulses which have four voltage levels (or phases or frequencies). Log2 of 4 = 2, so a four-level pulse can send, by the above definition, 2 bits of information. Thus, the information rate is double the pulse rate.
What's a Baud?
This is where baud comes in. Often we want to specify the pulse rate of a transmission which carries more than one bit of information per pulse. The baud rate of a digital signal is the number of symbols per second. For binary signals, bits and baud are the same. But for our four-level pulses, the information rate in bits per second is twice the baud rate in symbols per second.
Only very slow modems would transmit by binary signals. Combinations of phase, frequency and voltage enable 16 or more values per symbol to be used. As log2 of 16 is 4, each symbol (time segment) carries 4 bits of information and so a modem sending at 2400 baud is sending 9600 bits of information per second. To distinguish between these two rates, we need to use baud as well as bits.
Inside our computers, everything is binary since we aren't restricted by having to transmit over telephone lines. Bytes are groups of eight binary bits, which once conveyed most of the symbols we used. Now we use groups of 16 or even 32 bits for greater speed.
And nibbles? Half a byte (4 bits of information).
And Here Is The News
Microsoft and Stac Electronics have settled their dispute out of court. The two companies say they will work together on new technologies. As someone said, "It's incredible, Gates wins even when he loses."
Borland has put its corporate feet back on the ground by releasing a new Windows version of the Sidekick program, well-known and respected by earlier PC users. When first released, Sidekick could "pop up" and be used without the necessity to quit the program you were running. Heady stuff in those days, commonplace now with Windows.
Intel and Hewlett-Packard have made a deal to produce chips to power everything from mainframe to PC. Does this mean that the P6 (Sextium?) processor won't appear next year as scheduled?
That's all for this time. See you next month.....
Reprinted from the August 1994 issue of PC Update, the magazine of Melbourne PC User Group, Australia
