"Jonathan Kirwan" <j...@easystreet.com> wrote in message
news:v...@4ax.com...
> On Fri, 15 Jul 2005 18:24:50 GMT, Chafik Hankour
> <c...@gmail.invalid> wrote:
>
> >Jonathan Kirwan <j...@easystreet.com> wrote:
> >>
> >> A simple google turned up this:
> >>
> >>  http://web.mit.edu/storborg/Public/USBserial.pdf
> >>
> >> It provides complete board layout, schematics, BOM, etc.  You asked
> >> about a "chip" and this uses just such a thing and it may help you
> >> think out the idea more, in the context of medium volume.
> >>
> >> Jon
> >
> >A quick glance through the BOM shows the use of the FT232, serial to USB
> >converter, client only. The OP was looking for a host USB solution.
>
> Ah.  Noted!
>
> Isn't it possible to significantly pare down what a host needs to do,
> if there is ONLY going to be one and exactly one keyboard attached?
> Being ignorant of the details, it sure seems to me that it should be
> possible to set aside almost all of the host functionality and strip
> the need down to a much simpler system.

Yes, but then it wouldn't be USB.

On Fri, 15 Jul 2005 13:48:21 -0700, "Richard Henry" <r...@home.com>
wrote:

>> Isn't it possible to significantly pare down what a host needs to do,
>> if there is ONLY going to be one and exactly one keyboard attached?
>> Being ignorant of the details, it sure seems to me that it should be
>> possible to set aside almost all of the host functionality and strip
>> the need down to a much simpler system.
>
>Yes, but then it wouldn't be USB.

Well, if I understand the OP's need, it doesn't matter so long as it
works with a USB keyboard.  There's no need for supporting multiple
devices, no need for supplying full hub power capabilities, etc.  They
need the physical connector, the electrical physical signaling and
power so far as one keyboard is concerned, and the only that higher
level protocol support that is specifically required by USB keyboards.

AIUI, anyway.  

Jon

In article <v...@4ax.com>,
Jonathan Kirwan  <j...@easystreet.com> wrote:
>On Fri, 15 Jul 2005 18:24:50 GMT, Chafik Hankour
><c...@gmail.invalid> wrote:

Jonathan keeps asking the following:

>Ah.  Noted!

>Isn't it possible to significantly pare down what a host needs to do,
>if there is ONLY going to be one and exactly one keyboard attached?

No. USB was designed to make the client relatively simple at the cost
of making the host's job very tough. The expectation was that PC style
device you serve as the host.

I wonder about that USB to PS2 adapter though.

>Being ignorant of the details, it sure seems to me that it should be
>possible to set aside almost all of the host functionality and strip
>the need down to a much simpler system.

Doesn't work like that. There was supposed to be such a simpler spec in
the USB-on-the-go. But both devices have to participate for it to work.

If there were an easy host pare-down, then all of the micro manufacturers
would have done it a long time ago.

BAJ

Jonathan Kirwan wrote:
> "Richard Henry" <r...@home.com> wrote:
> 
>>> Isn't it possible to significantly pare down what a host needs
>>> to do, if there is ONLY going to be one and exactly one keyboard
>>> attached? Being ignorant of the details, it sure seems to me that
>>> it should be possible to set aside almost all of the host
>>> functionality and strip the need down to a much simpler system.
>>
>> Yes, but then it wouldn't be USB.
> 
> Well, if I understand the OP's need, it doesn't matter so long as
> it works with a USB keyboard.  There's no need for supporting
> multiple devices, no need for supplying full hub power capabilities,
> etc.  They need the physical connector, the electrical physical
> signaling and power so far as one keyboard is concerned, and the
> only that higher level protocol support that is specifically
> required by USB keyboards.

Well, color me stoopid, but I fail to see any reason somebody wants
to use a complex USB system, with attendant reliability, protocol,
and maintenance problems at both ends, rather than the simple, well
tested, readily available PS2 interface for a keyboard.

You will have no problem finding PS2 keyboards for 2 to 3 USD at
your local Salvation Army or Goodwill store.  Other countries may
need to look elsewhere, but they should still be more easily found
(and cheaper) than USB keyboards.

-- 
"If you want to post a followup via groups.google.com, don't use
 the broken "Reply" link at the bottom of the article.  Click on 
 "show options" at the top of the article, then click on the 
 "Reply" at the bottom of the article headers." - Keith Thompson

CBFalconer wrote:
>
> Well, color me stoopid, but I fail to see any reason somebody wants
> to use a complex USB system, with attendant reliability, protocol,
> and maintenance problems at both ends, rather than the simple, well
> tested, readily available PS2 interface for a keyboard.

I can't say I've ever noticed any reliability, protocol or maintenance
problems with any USB keyboard I've used.  Is that really a problem
with USB keyboards?  Anyway, my question is not really about the
complexity of USB, but about the complexity of using chips (and
attendent vendor code) designed to do USB.  I'm hoping that the state
of the USB-chip art is such that they can now do their complex thing
(in particular, their USB keyboard thing) with a minimum of our
engineering fuss.  I mean, we can put a man on the moon... :-\

As for PS/2 keyboards, I should look into the possibility.  Technically
they would be an easy solution.  What is the likelyhood, however, that
they will be available new (please, no Goodwill stores!) say, 10 years
from now?
>
> You will have no problem finding PS2 keyboards for 2 to 3 USD at
> your local Salvation Army or Goodwill store.  Other countries may
> need to look elsewhere, but they should still be more easily found
> (and cheaper) than USB keyboards.

But we would have a problem including them with our product and
expecting the customers to send us money, much less expecting them to
buy more of our products in the future.

On Sat, 16 Jul 2005 02:15:34 GMT, CBFalconer <c...@yahoo.com>
wrote:

>Well, color me stoopid, but I fail to see any reason somebody wants
>to use a complex USB system, with attendant reliability, protocol,
>and maintenance problems at both ends, rather than the simple, well
>tested, readily available PS2 interface for a keyboard.

I'd much rather support a PS/2 or standard AT keyboard connector.
However, as you may have noticed, the old larger-diameter AT keyboard
connector type keyboards are getting harder to find.  Especially new.
A *lot* of USB keyboards, some PS/2 -- and a few of the PS/2 ones will
include one of those adapters in them for the old connector.

Where does one buy an ISA bus system anymore??  And I like them for
building protos of my own.  I don't have the ability to work with PCI,
as reflection wave bus design with 1 and 2 nanosecond clock to data
skews, etc., are out of my hobbyist league.  Plain and simple.

I guess these things are why I didn't question the OP's direction and
instead took it on face value and went with it.

>You will have no problem finding PS2 keyboards for 2 to 3 USD at
>your local Salvation Army or Goodwill store.  Other countries may
>need to look elsewhere, but they should still be more easily found
>(and cheaper) than USB keyboards.

But for how long?  Do you know where to go to get an ISA floppy disk
controller?  Or an ISA hard disk controller?  Or one of those
multi-I/O controllers for the ISA?  I've got them still in boxes here,
but there is no way I could source one commercially, these days.

When planning products for long term availability, I can understand
someone desiring to look at the current situation and extrapolate a
bit to see what is changing and to plan for it.  At least, within
reasonable bounds.

The question, I suppose, is whether or not planning in a USB keyboard
connector is within reason.  There probably would be no argument from
you or others, were it the case that USB hosting was easy to do.  The
only reason there is an argument here is simply because there are real
risks and so folks quibble over that choice in the context of various
alternatives.  Ultimately, the OP is going to have to decide.  All we
can do is kibitz.

Jon

On 15 Jul 2005 20:12:10 -0400, b...@cc.gatech.edu (Byron A Jeff)
wrote:

>In article <v...@4ax.com>,
>Jonathan Kirwan  <j...@easystreet.com> wrote:
>>On Fri, 15 Jul 2005 18:24:50 GMT, Chafik Hankour
>><c...@gmail.invalid> wrote:
>
>Jonathan keeps asking the following:
>
>>Ah.  Noted!
>
>>Isn't it possible to significantly pare down what a host needs to do,
>>if there is ONLY going to be one and exactly one keyboard attached?
>
>No. USB was designed to make the client relatively simple at the cost
>of making the host's job very tough. The expectation was that PC style
>device you serve as the host.

I am glad for a direct answer (well, not so glad myself, but more
vicariously for the OP.)  But I have a hard time accepting this
assertion without the details.  Why?  It just seems that keyboard
support cannot possibly require every single feature of a general
purpose USB host.  I mean, each and every single one??  Really???

>I wonder about that USB to PS2 adapter though.
>
>>Being ignorant of the details, it sure seems to me that it should be
>>possible to set aside almost all of the host functionality and strip
>>the need down to a much simpler system.
>
>Doesn't work like that. There was supposed to be such a simpler spec in
>the USB-on-the-go. But both devices have to participate for it to work.

Hmm.  Okay, so there was some thought to the idea.  Just didn't
happen?

>If there were an easy host pare-down, then all of the micro manufacturers
>would have done it a long time ago.

Well, there's a point.  The only thing that comes to mind to perhaps
dispute this is that micro manufacturers don't know how their USB host
support is going to be used by a customer, so they *need* to supply a
general purpose support in order to reach a broader audience.  And
restricting the design they offer to some tiny, single purpose would
also too narrowly restrict their customer base and make it
unprofitable.

Jon

"Mike Silva" <s...@yahoo.com> wrote
>
> As for PS/2 keyboards, I should look into the possibility.  Technically
> they would be an easy solution.  What is the likelyhood, however, that
> they will be available new (please, no Goodwill stores!) say, 10 years
> from now?

Mike,

I think its hard to look ten years down the road see what's going to be 
available, USB or not. I don't think that much of anything that was around 
ten years ago is too easy to find today, EXCEPT for the PS/2 keyboards.

Serial keyboards will certainly be around for another three or more years. 
If the product does well and you're still in business, and PS/2 keyboards 
start going out of style, you will still have an opportunity to buy a ton of 
USB to PS/2 converters, which will buy you plenty of time to redesign your 
product.

Right now, the PS/2 solution is simple, affordable, reliable and a good 
business decision. IMHO, USB was designed by the big boys to try and keep 
the small guy from getting a piece of the pie.

[OT] Are you of any relation to Jose?

Mike

On 15 Jul 2005 19:46:55 -0700, "Mike Silva" <s...@yahoo.com>
wrote:

[Snipped]

>
>As for PS/2 keyboards, I should look into the possibility.  Technically
>they would be an easy solution.  What is the likelyhood, however, that
>they will be available new (please, no Goodwill stores!) say, 10 years
>from now?

I have an IBM PS/2 Keyboard that was manufacured in 1980.  So this
specific protocol has been around for 25 years. You might have to
order from a higher level supplier than Joe's Cheapest Computers down
the road.
One can buy the better keyboards from industrial suppliers with all
sorts of interfaces. 

[Snipped]

>
>But we would have a problem including them with our product and
>expecting the customers to send us money, much less expecting them to
>buy more of our products in the future.

I think as long as you can supply the neede keyboard as an option,
most people should be able to source a cheap PS/2 keyboard without 
to much problems for the next 10 years. If you force your customers to
buy an "expensive" keyboard when they can get a US$2 around the corner
will piss them off. Giving them the option keeps everybody happy.
Just make it very clear in your spec overview that the keyboard is a
stock standard PS/2 keyboard.

Regards
  Anton Erasmus

Mike Silva wrote:

> I did search for PS/2 keyboards but only found USB keyboards for
> PlayStation 2s.

I suspect misunderstanding here.  PS/2 does *not* mean PlayStation 2 in 
this context.  It is the name of IBM's system introduced in '87:

http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html
http://www.tavi.co.uk/ps2pages/ohland/keyboard.html


> []... Thanks for expanding my horizons!

You are mostly welcome.

   Vadim