Page 12 of 16
wrote:

You're wrong.

krw wrote:

Hmm.. The reason calculators don't use binary is because the translation from decimal to binary to do a calculation, and then convert to decimal output again is generally less efficient than using BCD. Just saying...

Only on the old BCD mainframes was any form of base-16 used, and there, values of A-F weren't available for use (they were called undigits on the Burroughs systems and would cause a fault if used in an arithmetic operation - integer, fixed-point or floating point.

All modern processors do arithmetic in binary[*]. Don't confuse the storage format with the human representation of the storage when printed.

[*] IBM's Power processors also support decimal floating point (a la BCD).

No, that's not it. That is how to up grade the fingers of your DT jig to a later version past the D4. You can buy the new set of fingers that are identical in size and shape, except for the extra holes in the set or you can make yours the same by drilling the hikes in those odd sizes and locations.

That was my first thought, because that's a common problem. The examples Leon gives don't seem to translate to any sensible fraction of an Imperial unit. 3.57mm isn't one of the letter/number system of drill sizes either, altho it's a little bigger than a #28.

Possibly the odd values are accumulated rounding error, due to going metric to imperial and back to metric.

John

Yeah, I read Graham's post before yours.

John

#### Site Timeline

- posted on September 17, 2016, 11:02 pm

You're wrong.

- posted on September 17, 2016, 11:16 pm

Hmm.. The reason calculators don't use binary is because the translation from decimal to binary to do a calculation, and then convert to decimal output again is generally less efficient than using BCD. Just saying...

- posted on September 18, 2016, 12:01 am

wrote:

As I said, you're wrong. Conversion is a trivial matter (modulo divide by "10" and post the answer to the display - repeat). The problem is adding 1/3 + 2/3. People understand that .3333333333 is 1/3 and .666666666 is 2/3 but they don't like the answer to be .999999999. The logic to make it "right" in every case wasn't trivial for early calculators.

As I said, you're wrong. Conversion is a trivial matter (modulo divide by "10" and post the answer to the display - repeat). The problem is adding 1/3 + 2/3. People understand that .3333333333 is 1/3 and .666666666 is 2/3 but they don't like the answer to be .999999999. The logic to make it "right" in every case wasn't trivial for early calculators.

- posted on September 17, 2016, 3:21 am

wrote:

Of course but because machines like binary and we don't, doesn't mean it's the only use.

Of course but because machines like binary and we don't, doesn't mean it's the only use.

- posted on September 17, 2016, 11:43 am

4ax.com:

If we'd simply stop counting our thumbs and use them as status bits instead, binary would come a whole lot more naturally. Teach your kids to count properly: One, two, three, four, overflow, sign, five, six, seven, eight.

The status bits might need a bit more thought.

Puckdropper

If we'd simply stop counting our thumbs and use them as status bits instead, binary would come a whole lot more naturally. Teach your kids to count properly: One, two, three, four, overflow, sign, five, six, seven, eight.

The status bits might need a bit more thought.

Puckdropper

- posted on September 17, 2016, 2:36 pm

On 17 Sep 2016 11:43:21 GMT, Puckdropper
*<puckdropper(at)yahoo(dot)com> wrote: *

How about using them for hexadecimal. It might take some Vulcan coordination, however.

Status bits seem pretty simple, at least for your base-8. Increment right to left, decrement left to right. Overflow then becomes the count after either pinkie (pinkie and ring change together) and sign becomes a decrement or increment past zero.

How about using them for hexadecimal. It might take some Vulcan coordination, however.

Status bits seem pretty simple, at least for your base-8. Increment right to left, decrement left to right. Overflow then becomes the count after either pinkie (pinkie and ring change together) and sign becomes a decrement or increment past zero.

- posted on September 16, 2016, 2:02 pm

Only on the old BCD mainframes was any form of base-16 used, and there, values of A-F weren't available for use (they were called undigits on the Burroughs systems and would cause a fault if used in an arithmetic operation - integer, fixed-point or floating point.

All modern processors do arithmetic in binary[*]. Don't confuse the storage format with the human representation of the storage when printed.

[*] IBM's Power processors also support decimal floating point (a la BCD).

- posted on September 17, 2016, 3:27 am

On Fri, 16 Sep 2016 14:02:10 GMT, snipped-for-privacy@slp53.sl.home (Scott Lurndal)
wrote:

Huh? How can you have base-16 arithmetic and not use A-F? That paragraph makes no sense.

It depends on how you look at it. The hardware uses binary logic, sure, but the arithmetic is purely hexadecimal. Normalization is done in hexadecimal digits and the "binary point" is actually a "hexadecimal point", for instance.

Again, who was talking about BCD?

Huh? How can you have base-16 arithmetic and not use A-F? That paragraph makes no sense.

It depends on how you look at it. The hardware uses binary logic, sure, but the arithmetic is purely hexadecimal. Normalization is done in hexadecimal digits and the "binary point" is actually a "hexadecimal point", for instance.

Again, who was talking about BCD?

- posted on September 15, 2016, 3:31 pm

Puckdropper <puckdropper(at)yahoo(dot)com> wrote in

You are exactly correct - computers use base 2 because of the hardware, it has nothing to do with arithmetic (some early computers used base 3, which is easy to implement in an analog computer and does make some arithmetic easier).

Programmers use hex (base 16) because it's easier than a whole bunch of 1s and 0s. Experienced programmers can do basic math in hex in their head, whereas no-one can do math in their head with binary numbers bigger than a few digits (other than multiply/divide by 2, of course).

John

You are exactly correct - computers use base 2 because of the hardware, it has nothing to do with arithmetic (some early computers used base 3, which is easy to implement in an analog computer and does make some arithmetic easier).

Programmers use hex (base 16) because it's easier than a whole bunch of 1s and 0s. Experienced programmers can do basic math in hex in their head, whereas no-one can do math in their head with binary numbers bigger than a few digits (other than multiply/divide by 2, of course).

John

- posted on September 15, 2016, 10:53 pm

John McCoy wrote:

Or we can quickly convert binary to decimal, perform the operation and convert back! : ) No prob.

Or we can quickly convert binary to decimal, perform the operation and convert back! : ) No prob.

- posted on September 16, 2016, 1:22 am

On Wed, 14 Sep 2016 15:40:49 -0700,

In most of life, close enough is, well, close enough.

But no one can decide what the base unit should be. Some like microns (micrometers), others use angstroms. That's just the tip of the iceberg, too.

When I'm measuring, I avoid the bookkeeping by deciding on my result ion and then calculate using just the numerator. For instance, if 1/32" is "good enough", I don't use 1/2" or 1/4", rather 16(/32) or 8(/32).

*<...> *

They taught us arithmetic in different bases, up to base-32 (and, of course conversion between them) in fifth and sixth grade.

In most of life, close enough is, well, close enough.

But no one can decide what the base unit should be. Some like microns (micrometers), others use angstroms. That's just the tip of the iceberg, too.

When I'm measuring, I avoid the bookkeeping by deciding on my result ion and then calculate using just the numerator. For instance, if 1/32" is "good enough", I don't use 1/2" or 1/4", rather 16(/32) or 8(/32).

They taught us arithmetic in different bases, up to base-32 (and, of course conversion between them) in fifth and sixth grade.

- posted on August 5, 2016, 10:23 pm

On 8/5/2016 3:16 PM, Leon wrote:

Those fractions are probably due to conversion from Imperial Measure. I've seen analogous measurements in cookbooks for the US market where they have obviously converted metric to imperial weights and measurements. For example, I've seen a recipe asking for 1.76oz instead of the original 50g. Honestly, metric is MUCH easier if you work in it from scratch. Graham

Those fractions are probably due to conversion from Imperial Measure. I've seen analogous measurements in cookbooks for the US market where they have obviously converted metric to imperial weights and measurements. For example, I've seen a recipe asking for 1.76oz instead of the original 50g. Honestly, metric is MUCH easier if you work in it from scratch. Graham

- posted on August 6, 2016, 1:54 am

On 8/5/2016 5:23 PM, graham wrote:

That would be a logical explanation but they the Leigh Jig and the slides are manufactured in a metric country and the slide have measurements that are clearly even number mm's and are made to the 35mm system. And the measuring of the holes on the slides don't really need to be any specific measurement at all.

That would be a logical explanation but they the Leigh Jig and the slides are manufactured in a metric country and the slide have measurements that are clearly even number mm's and are made to the 35mm system. And the measuring of the holes on the slides don't really need to be any specific measurement at all.

- posted on August 6, 2016, 2:24 am

On 8/5/2016 7:54 PM, Leon wrote:

It depends on when it was made. Graham

It depends on when it was made. Graham

- posted on August 6, 2016, 2:33 am

On 8/5/2016 9:24 PM, graham wrote:

October 14, 2014. ;~) Does that shed more light? LOL

October 14, 2014. ;~) Does that shed more light? LOL

- posted on August 6, 2016, 3:45 am

On 8/5/2016 8:33 PM, Leon wrote:

They've been on the market for over 30 years. I would imagine he hasn't bothered to retool.

They've been on the market for over 30 years. I would imagine he hasn't bothered to retool.

- posted on August 7, 2016, 2:09 pm

No, that's not it. That is how to up grade the fingers of your DT jig to a later version past the D4. You can buy the new set of fingers that are identical in size and shape, except for the extra holes in the set or you can make yours the same by drilling the hikes in those odd sizes and locations.

- posted on August 6, 2016, 2:47 pm

That was my first thought, because that's a common problem. The examples Leon gives don't seem to translate to any sensible fraction of an Imperial unit. 3.57mm isn't one of the letter/number system of drill sizes either, altho it's a little bigger than a #28.

Possibly the odd values are accumulated rounding error, due to going metric to imperial and back to metric.

John

- posted on August 6, 2016, 5:05 pm

On 08/06/2016 9:47 AM, John McCoy wrote:

...

As I showed earlier, it's 9/64"...

9/64*25.4 = 3.571875000...

The other is 7/64"; both are common pilot-hole drill sizes...

...

As I showed earlier, it's 9/64"...

9/64*25.4 = 3.571875000...

The other is 7/64"; both are common pilot-hole drill sizes...

--

- posted on August 6, 2016, 7:35 pm

Yeah, I read Graham's post before yours.

John

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