Hardware that Requires software WAS: TL-WN722N support

Adam Vande More amvandemore at gmail.com
Thu Aug 28 19:46:06 UTC 2014

On Thu, Aug 28, 2014 at 9:16 AM, Paul Kraus <paul at kraus-haus.org> wrote:

> On Aug 27, 2014, at 23:33, Polytropon <freebsd at edvax.de> wrote:
> > Yes, those are terrible and years behind technological evolution.
> > The same applies to "WinModems", a disease that development has
> > fortunately dealt with.
> It is helpful to understand the why of something, and explain such, rather
> than just condemn it as bad.

Let be through in such an understanding then.

The move to host based software for things like printers, modems, scanners,
> and other various hardware came about because the performance of the
> general purpose computer was increasing at least at Moore’s Law rate, if
> not faster. By moving the processing of the raw data into code the device
> (printer, scanner, modem, etc.) could use onto the host OS you got two big
> advantages:
> 1. As the host systems got faster so did your device

Not nessicarily, many of these software driven devices were bottle-necked
by bus communication speeds and mostly upgrading CPU/RAM/board wouldn't
help you a bit.

> 2. Your device was likely to remain useful for a longer period

I'm not sure how this conclusion was drawn.  Assuming you didn't want to
switch OS's and you didn't experience any s/w driver related over time and
no other OS magnificence were incurred, at best you hope for is that is
would last as long as a hw driven device.  There was a reason there
software devices were cheaper and it had nothing to do with reliability.

There is a third advantage, that the device can be less intelligent and
> less powerful, making it cheaper. The typical desktop computer today has
> lots and lots of spare CPU cycles (and generally speaking, has for at least
> a decade). Why not make good use of those resources.

The contemporary serial port of 1998 is basically the same as the ones sold
today.  Who cares how many CPU cycles there are if transport to/from it is
on the same interval?  CPU load on a soft modem using a K6 proc wasn't
overly bad anyway.  That was never the problem by the time these things
were mass produced.

I have three scanners in the house that *all* require very custom software
> as the processing of the raw scanned data from the image sensor is
> happening on the host system and not on the scanner hardware. I have seen
> marked improvements in image quality with each update of the management
> software. Even older hardware, hardware that the vendor would no longer be
> supporting if it were more complex is still on the supported list.

I'm not aware of any scanner where the processing(raw->image container)
occurs on the scanner.  Not to say there aren't some, but those would be
the corner cases and likely very high end.  Since CPU for a very long time
have had specific instructions sets for these operations it only makes
sense to do it host side.

> Does it mean that you cannot use this hardware on OSes for which there is
> no software support? Absolutely, but that is the case for *everything*. If
> you know you need to (or want to) runs a certain OS, for whatever reasons,
> then you buy hardware that is supported by that OS.

Right on, but the extra 20 - 50% in cost for a hw device rather than a
device specifically supported only by one version or family of OS is a drop
in the bucket compared to installing, maintaining, and being competent in
all major OS's.  I've got better things to do than track down improperly
installed(or uninstalled, or updated) drivers and handle upgrades and
updates over time on a sub-$200 piece of equipment.


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