1. Time to Doodle and Twiddle Your Thumbs
2. On the Road with Magnetic Media
3. Accepting a New Technology
4. Catching the Next WAV
5. Wiggle Your Toes
6. A New Format and Why You Shouldn't
7. The Upgrade Train
8. I/O Bound
9. Solving the Wrong Problem
10. Tape Backups
11. Interleaving
12. Floppy Drive Compatibility

<System Basics : Table of Contents : I/O Cards>

Time to Doodle and Twiddle Your Thumbs
From Catalog 38, page 29

Is your time worth $6 an hour? If the answer is yes, then please consider the following!

Formatting a box of 10 diskettes with verify turned off will take between 18 and 25 minutes. Depending on your machine and the capacity of the disk, it could take even longer. Using twenty minutes and a $2 increase for each box of diskettes as a guide, then your time must be worth less than $6 an hour for you to come out ahead.

Formatting a QIC tape usually takes about 40 minutes, twice that if you verify after format. Again we find that for a format only, if your time is worth more than $6 per hour, you should be buying preformatted tapes.

Time it yourself, it's true. Even though we usually only format one disk at a time, the minutes mount up quickly. And don't forget, disks formatted at the factory are usually more reliable because the equipment used is more precise.

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On the Road with Magnetic Media
From Catalog 34, page 8

How dangerous is the X-ray machine at the airport, and what can I do to protect my diskettes and tapes when they have to travel?

You will be happy to know that the baggage scanning devices at all major airports are designed to minimize magnetic interference that could destroy data on your magnetic media. If you are traveling in what once were iron curtain countries, consider having disks and tapes hand-inspected since some of the older, cheaper machines create considerable magnetic fields.

The real dangers for magnetic media are primarily heat, then cold, and lastly moisture. Never leave your disks in an enclosed car, trunk, or on a heated surface (like the top of your monitor). Usually, the packaging will curl and shrink before the mylar substrate with the magnetic surface. If this happens, you can frequently recover your data by putting the magnetic media in a new envelope or case.

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Accepting a New Technology
From Catalog 34, page 16

Aside from the obvious resistance to change just because it requires we learn something new, most of us can find at least one good reason to justify that resistance in real terms. One example is the switch from mechanical drafting to electronic CAD and modeling. Anyone whose first training was with a T-square and French curves is naturally resistant to working on a 17 to 20+ inch screen with a mouse and keyboard. They know, quite correctly, that they are more productive with the old tools than they will be for quite some time with the computer version. The justification is that all of the previous work is on paper, and that much of their effort goes to revisions of that paper.

But you can't hold back progress, and someone is always trying to make the transition easier. The graphic tablet is a great example for this illustration. Not only does the tablet allow the designer to use a tool which in many ways replicates the old board and paper environment, it also facilitates the conversion of the paper document to the electronic medium. With little training or experience, a user can digitize the important coordinates from the paper representation into a computer image for further changes and revisions.

Since you and I cannot hold progress back, I have determined I will be an early adaptor. There may be risks associated with early adapting, but one of them isn't a concern that I'll become obsolete.

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Catching the Next WAV
From Catalog 29, page 27

In much the same way the CD-ROM's are becoming the recording industry's dominant publishing medium, they are also well on their way in the PC industry.

As the requirements for bigger and better programs reach higher and higher plateaus, the number of floppies required to distribute them has doubled and doubled again. No longer can you expect to install a major application or operating system from a disk or two!

Consider the developer's dilemma: they can either deliver on 10 floppies at $2 per disk or on one CD-ROM (with all the extras including on-line help and clip-art) for $5 per disk! You will help them and yourself by having a CD-ROM drive.

Today, multimedia is still a catch phrase, but by the end of this year, with the help of Windows, Windows NT, and OS/2, you can expect major strides in both video and sound (WAV files). CD-ROM's will change the way you think about data! No longer do megabytes of help files look like burdensome overhead. Having clip-art on your disk doesn't mean you have to remove something else just as useful.

Oh, and by the way_when you aren't accessing your CD-ROM drive for data, you can always play your favorite music in the background! Just think of it, music to program by... like "It's been a hard day's night."

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Wiggle Your Toes
From Catalog 27, page 35

Much like a pair of shoes that are too tight or a bed that is too short, a disk drive without sufficient capacity can be very uncomfortable, indeed.

I just added 245 megabytes of capacity to my main work computer. I didn't need more than about 20 megabytes right now, but experience tells me that by this time next year that disk will probably be full. I considered a larger disk, but decided that I can find a home for this drive when I outgrow it.

The decision to add 245 megabytes was based on both budget considerations and dollars per megabyte. At just over $2 per megabyte, the ST-3283A was a hands-down winner over what I might have gotten by with.

You don't have to make your decisions on emotions or the flip of a coin. Assess your medium to long-term needs, fire up your calculator or, better yet, your spreadsheet, and make a reasoned decision.

From over $2 per megabyte to less than a dollar per megabyte. Sure, I knew it was bound to happen, but who thought it would happen so fast. I just checked the latest catalog #38, and found that 14 of the 20 hard drives listed are selling for less than $1 per meg. They range in size from 261 megabytes to 2.16 gigabytes.

There has to be a lower limit to the cost per meg, but we don't seem to be there yet. Now, if we could only stop the spiraling inflation in program size we might really have a deal going.

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A New Format and Why You Shouldn't
From Catalog 27, page 26

IDE drives and controllers are considerably less expensive than the alternatives. In fact, the differential is so great that many users faced with increased storage requirements are putting their old equipment in the closet and starting from scratch with a new IDE controller and drive instead of just buying an additional drive.

Judging by the title, it sounds like I am opposed to that idea. Not so. The title is a warning not to "low-level" reformat an IDE drive.

IDE drives are less expensive because they take advantage of "zone" recording. The circumference of an inner track is much less than the circumference of an outer track. ESDI, RLL, and MFM drives are usually recorded at the maximum density possible for an inner track no matter which is being recorded.

An IDE drive will have several zones, and outer tracks will contain more data than those closer to the hub. As a consequence, much more data can be recorded on an IDE drive (SCSI too) than has heretofore been normal.

Low level formatting is forbidden because it would destroy the "zone" recording and waste megabytes of storage capacity.

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The Upgrade Train
From Catalog 26, page 26

I wanted a 386 so I could run all of the GUI'y new programs, but I needed a VGA card and monitor, so I could see all the stuff I was missing. And it would be unnatural to have a powerful computer and display without a larger, faster hard disk, so that should probably be my first acquisition.

But you can't manage all that stuff without a mouse or graphics tablet, and SimCity runs better with one. All this is getting expensive_Maybe I better get a 9600 baud modem. I'll save so much money on software and phone charges that I might be able to afford another 4Mb of memory. Does this remind you of anyone you know? Don't expect answers from me. Console yourself with the knowledge that as long as you ride, you won't be left too far behind. In the world of computers, hardware becomes obsolete faster than the software that drives it.

My advice is to find a friend who will buy your hand-me-downs, so you won't end up with lots of spare parts. And don't tell them about JDR, or you may have to find a new customer when they decide to ride the upgrade train themselves!

I stopped at every station along the way, but I never stopped for long. That 386 became a faster 386, then a 486-25 followed by my current 486DX2-66. The VGA was replaced by an SVGA with 1 meg of memory, then by a VESA SVGA with a 14" 1024 x 768 non-interlaced display, and then a 15 inch ADI display which I must confess is terrific.

And the 2400 bps modem became a 9600 bps fax/modem which was replaced by a 14,400 bps fax/modem. Each and every one of those old parts found a home in someone else's PC. My hobby/vocation has a price, but I keep the costs down, and make many people happy with my good deals on slightly used parts.

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I/O Bound
From Catalog 24, page 13

When a computer system spends much of its time waiting for peripherals like the hard disk or video display, it is said to be "I/O bound."

First, we wait for the disk drive to become ready, then seek, rotate to a position under the head, and finally read in or write out the data. If the program happens to be performing a "sort" operation on disk data, the disk could be tied up for several minutes.

In this situation, a faster processor will make little difference. The fastest 386 computer might only improve performance by 15%.

If your hard disk seems slow, consider this: drives purchased a few years ago took 85 milliseconds to seek the heads and required 4 to 5 revolutions of the disk to read 8.5K of data.

Many current drives average 28ms or less to get on track and with a 1:1 interleave controller, can read a full track in one revolution.

So much of the advice here is now obsolete that it may tend to confuse, but the basic premise is still the same. If you have a slow disk drive, a faster processor won't have much effect on disk access times unless you elect to create a large disk cache in main memory.

A good drive today has an average access time under 15ms with the fastest drives reaching below 10ms. Because processors have sufficient processing power for 1:1 interleave on even the fastest drives, many drives today can sustain data rates more than 10 times the speed available just 2-3 years ago.

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Solving the Wrong Problem
From Catalog 20, page 24

Is your 286-based PC slow in running your applications? We'd love to sell you a new 486 PC with all the trimmings, but do you need it?

Where are the bottlenecks? Does your hard disk light flicker for seconds (minutes) at a time while your program executes? Do you leave for coffee when you start Windows? Does your CAD program grind forever on displaying the shuttle Columbia?

The fixes for each problem might be different. Extended disk activity might require a 16-bit disk controller with very fast data transfer and a 1:1 interleave. An IDE controller and high capacity drive buffered with a disk caching program can reduce 5 minutes of disk activity.

Slow Windows may benefit more from a Windows accelerator VGA card than from a new motherboard. As for the slow CAD program, if you don't have a math co-processor, that might be your best move. Or just maybe you should jump to a 486 PC.

Something funny's going on here.....

I sure wish I could find the original text for this column. The second to last paragraph just kind of trails off into nowhere (and I would nver mak a mistrake lik taht).

I think it should have said something like "can reduce five minutes of disk activity to 15-20 seconds". One of the most impressive things I have found that I can do for people with "slow computers" is convince them to purchase memory for a disk cache or a caching disk controller.

Without the cost or hassle of a new motherboard, I can usually produce time reductions of 80-90% for database searches, reindexing and sort operations on disk data.

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Tape Backups
From Catalog 12, page 27

Way back in April of 1990, I had good occasion to appreciate the Archive tape backup that was installed in my computer at work.

A full height 20 megabyte hard disk that I had been using for about 4-1/2 years bit the dust. I thought that drive was great_ It had been with me in four different machines!

First I had it installed in a real IBM PC. Later it moved to new quarters in a Turbo PC, then a 286, and finally to a 386 machine in an upright case. Is it any wonder that I believed it was bulletproof!?

Now the sad part... in the first paragraph I said, "I had good occasion." What I did not say was that I had not taken advantage of my opportunities. I am still suffering the bad effects of not having a backup copy of that hard disk. I have a good excuse, as if anyone cares, but more important is this counsel: anything built by human hands is going to break down sometime. If your data is important, back it up. A floppy backup is fine, but a tape backup makes it so much easier, you'll be more inclined to do it.

For the record... My tape backup is current as of last week and I do a complete backup every month whether I need it or not. I learned my lesson

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Interleaving
From Catalog 9, page 24

If you feel your hard disk is too slow, the solution to your problem may require nothing more than the time it takes to low level REFORMAT your disk at the optimum INTERLEAVE.

Interleaving is beneficial whenever the hard disk can transfer data faster than the CPU can accept it. During the 16.6ms it takes for one revolution of the disk, approximately 8,704 characters of data can be read from one track.* If the processor cannot keep up, the proper interleave will help.

The optimum interleave is determined by the number of characters the processor can accept in one revolution. For example, let's say the processor can accept 3,702 characters in 16.6ms.

Instead of numbering the sectors sequentially from 1 to 17, we will reformat the sector numbering. With an interleave factor of 3, the sectors will be numbered 1-7-13-2-8-14-3-9-15-4-10-16-5-11-17-6-12.

This allows the CPU to store the data for sector #1 while #7 and #13 are passing under the read/write head, and then continue with sector #2 when it is ready. In one revolution, six sectors of 512 bytes will be read and stored. In three revolutions, all of the sectors will be read. Any interleave other than three will, in this example, cause disk access time to increase.

* Note: Usually each track is divided into 17 sectors (sections) of 512 bytes (characters) per sector.

Unless you are still using an older MFM or RLL drive, this information is useless. All of the newer drives come low-level preformatted and should never be reformatted.

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Floppy Drive Compatibility
From Catalog 8, page 24

Ever wonder about floppy drive compatibility? You should!

There are 360K 5-1/4", 720K 3-1/2", 1.2 meg 5-1/4", and 1.44 meg 3-1/2" drives, any of which can be used on most PCs and PC clones. Improvements in floppy controllers make using high density drives on 8088-based machines a viable option.

With so many possibilities, the choice becomes more difficult, so let's eliminate some of the redundancies. First, a 1.2 meg drive can work with both high density 1.2 meg floppies and low density 360K floppies. And second, a high density 1.44 meg drive can use both high density 1.44 meg and low density 720K disks.

Unless you know you'll never need high density capability, eliminate low density drives from consideration. And, since nearly all computer cabinets are designed for at least two half-height floppies, one of each is a good universal recommendation.

Now for the bomb! The IBM PS/2 uses a different method to distinguish between 720K and 1.44 meg drives than the rest of the pack. While most of the manufacturers look for and detect the high density hole in a high density diskette, PS/2's read the data to make that determination. This causes a problem when a Low Density disk without the hole is written in the high density mode. So, if you get a 3-1/2" disk that a friend says is formatted at 1.44 meg, make sure it has the high density hole or it probably won't read in your clone.

With so much activity occurring in the CD-ROM and hard disk areas, it would be easy to overlook the improvements occurring in floppy drives. Without much fanfare, density has doubled again. Yesterday's 1.44 meg drives are quietly being replaced with 2.88 meg devices.

While some of the older 1.44 drives could not distinguish between an unformatted low or high density diskette, the new 2.88 meg drives correctly identify all three densities. I am particularly happy with my MCT-FDC-ED card and FDD-2.88A drive. And, a side benefit of using the ED (Extra Density) card is that my tape drive also works twice as fast for half the price of the card the drive manufacturer sells.

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