What the system can reveal
When starting out on finding what's missing or what's wrong, preventing SANE from working the scanner, I ended up becoming properly confused.
Searching the net for information on this scanner, I got the impression that either all work has stalled or I was missing out on some important bits of information. But more important; I found inconsistencies all over the board, all the way from what models Mustek claims to have made to what product different lists declared the vendorID/productID resolved to.
For instance on the back of the scanner there's a plate that reads
"Mustek PageExpress A3 USB 1200 PRO".
On the other hand 'lsusb' says
Bus 002 Device 006: ID 055f:040b Mustek Systems, Inc. ScanExpress A3 USB 1200 PRO
Running 'sudo lsusb -v -d 055f:040b', it starts off with
Bus 002 Device 006: ID 055f:040b Mustek Systems, Inc. ScanExpress A3 USB 1200 PRO
[...]"
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x055f Mustek Systems, Inc.
idProduct 0x040b ScanExpress A3 USB 1200 PRO
bcdDevice 1.00
iManufacturer 1 Hewlett-Packard.
iProduct 2 USB2.0 Scanner
iSerial 0
bNumConfigurations 1
So I read this as being a Mustek product, a USB2.0 Scanner named "ScanExpress A3 USB 1200 PRO" that was manufactured by Hewlett-Packard:
{
idVendor 0x055f Mustek Systems, Inc.
idProduct 0x040b ScanExpress A3 USB 1200 PRO
iManufacturer 1 Hewlett-Packard.
iProduct 2 USB2.0 Scanner
}
However when searching in the SANE database for Vendor-ID=055f and Product-ID=040b it is registered as "BearPaw 6400 TA Pro" and NOT "ScanExpress A3 USB 1200 PRO". I don't know if this actually means that "BearPaw 6400 TA Pro" is just another marketing name used, or if it's a genuine/different product. If they are in fact geometrically identical "twins" there should be no problem, but if they are geometrically different it may hard to write a driver for the one that doesn't damage the other.
If someone knows more about this it would be helpful.
This page over at SANE gives a listing of unsupported devices, and it doesn't help in getting things sorted. I really wonder if someone have more details on what HW went into the different USB-scanners from Mustek ...
I also wanted to see if there was something to learn from taking a look at the controller-board inside the scanner, and the controller-chip is in fact a SQ113C. The board itself has a silk-print reading "A3IIIU2 Main Board 59-239-01000 Rev.A", nicely tying in with Mustek's naming of their binary only backend package A3IIIU2.
On a different note; it may seem like it hasn't been any development on these drivers since 2008 ...
I intend to learn more about how these backends sources are working, and are toying with ideas how to make it easier to include closely related scanners in the future. But for all I know these thoughts might be irrelevant or impossible - I have never dabbled with SANE source before, this may well be interesting :)
Published: 20/11-2017 (Gjermund Skogstad)