Windows10 drivers: The "strange" USB-41 case. (long)

[Diego Diaz]

Hi all,

Some of you have been following the thread regarding a new programmer for the Clonix/NoV modules, aimed to avoid the problems caused by Windows10 and its automatic drivers "upgrade".

Back in the day when I decided to design a module to connect the HP-41 with a PC using a USB<>serial converter interface, it seemed a good idea to use the same type of interface that were already present in the programmers.

By doing so, the users didn't need to install yet another driver on their PCs.

Regrettably I couldn't (no one could) anticipate the forecoming troubles derived from said Windows10 drivers upgrade policy.

The solution for the programmer side of the trouble is about to be available in the next few weeks. However, USB-41 modules not only need a new programmer but also a new interface.

The whole thing becomes a bit more weird because not every USB-41 use "exactly" the same interface chip. I became aware of this years after I built these modules.

Prolific PL2303 chips have been around for about to decades now, and have "suffered" a lot of design changes/upgrades. It is low cost, simple and efficient in design.

To turn things even worse, there are uncountable fake replicas of the different PL2303 families.

Up to Win7 the user can select the driver he/she wants into their PCs; it will remain active forever or until the user decided to upgrade it.

From Win8 ahead, the Driver's Signature came into force and the users are no longer the owners of their PC's contents. Too bad in my honest opinion and I'm not biased by the current PL2303 problem; just I don't like the idea that any "automatic-whatever" to have precedence over my own decisions. (Remember tragic Boeing 737-MAX.)

Back to far less dramatic USB-41 case, some of them use PL2303s that are surprisingly compatible with "some" of the upgraded drivers, while some others don't and can only work with the well known Win7 (ver. 3.3.11.152). Even though they seem to be of the same family.

And there are a huge number of families: "Windows Driver Installer Setup Program
(For PL2303 HXD, SA, TA, TB, RA GC, GS, GT, GL, GE , GD, GR versions)"; source :Prolific web. Note that some previous versions like A or HX are not even listed along with these.

With such a number of variants and the unbearable number of fake parts around it seems that finding a solution that could guarantee functionality in the long term based on this chips is out of the scope of a "single man project".

I'm about testing candidates to replace the PL2303 chips in the USB-41 modules. A promising alternative is the FT232, manufactured by FTDI and which (although it's also venerable in terms of longevity) has kept a very stable functionality in regards with the different Windows drivers along all these years.

I'll keep posting about this subject as I find relevant info to share. Meanwhile, if you are concerned about your USB-41 functionality or upgrade alternatives, please feel free to post here or mail me directly.

Best wishes and have a nice day.

Diego.

[Christoph Giesselink]

Also an alternative to the Prolific and FTDI chips could be the Silicon Labs CP210x family. They are used in DM Voyager family for example.

[Diego Diaz]

Thanks for the reference Christoph.

Will check out to see if I can find interfaces built with these chips.

Best regards.

Diego.

[techlover]

(08-09-2020 01:20 PM)Diego Diaz Wrote:  Thanks for the reference Christoph.

Will check out to see if I can find interfaces built with these chips.

Best regards.

Diego.

Did you find something?

[Diego Diaz]

Hi,

Nope, at least not the kind of boards that fits into USB-41 interface housing.

So far only the FT232 matches both size and function.

The unidirectional PRINTER application works without the need of any mods in the USB firmware.

I've tested this in a number of PC's with different Win versions.

Thae page transfer utility on the contrary has some timing or level handling problem that causes HP-41->PC function to fail every now and then. PC->HP-41 works ok without mods though.

Still more to check with the o'scope but indeed promising. At least, no driver problems arised so far. :-D

Have a nice day.

Diego.