VOICE Newsletter 03/2003 - USB CompactFlash readers under OS/2

Virtual OS/2 International Consumer Education

VOICE Home Page: http://www.os2voice.org

March 2003

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USB CompactFlash readers under OS/2

By Mark Dodel© March 2003

I've been promising to write an article on USB CompactFlash readers for some time now. I've started writing several times and always gave up. It wasn't writer's block; it was that I couldn't get a handle on how this USB Mass Storage device stuff works (or in my case usually didn't work). My first attempt to use a USB Compact Flash was prompted by my success with adding a External PCMCIA Travelstar hard drive to my Toshiba Satellite laptop. That forced me to stop using my PCMCIA CompactFlash adapter to read my digital camera's pictures because between the hard drive and my wireless network card taking up the two PCMCIA slots, I had no place to put it anymore. True, I could remove one or the other temporarily, but I wanted a better solution.

After years of wondering why anyone would need to use a USB device, I finally thought this might be a reason to buy one as my laptop had a USB port. Finally a reason to install the USB basic and the USB Mass Storage driver available with eComStation and IBM's Software Choice. There are also free versions of these available on Hobbes. A really good resource for information about USB under OS/2 is the OS/2 World USB site. They list available drivers, links to USB related articles, tips, as well as some reports of devices that work under OS/2 and what driver versions were successful.

My Toshiba Satellite 2545XCDT Laptop is getting a bit old now, and also doesn't have an Intel chipset. The original OS/2 USB drivers did not support the OHCI USB chipset that was in this laptop, only UHCI, but later versions added this capability so I decided to give it a try. The most recent version, USB 2.0, is called EHCI. For more on USB see the USB FAQ.

I couldn't find much about USB CompactFlash readers and OS/2 other then that if the device was "USB Mass Storage Device" compliant it should work with the IBM OS/2 USBMSD driver. I checked my local Staples office supply store to see what they carried in the way of USB devices. I initially only found a Sandisk ImageMate SDDR-75 USB dual card reader for about $30US. It could read both CompactFlash and SmartMedia cards.

According to the SanDisk web site this product is " Mass Storage Class (MSC) compliant" so I made the assumption it should work under OS/2. The reader looked like an oversized mouse, with two slots in the front and a short USB cord on the back. When I plugged it into my USB port the red power light came on. And with plugging in a CF card the Slot2 green LED lit up. Using an older USBMSD driver I had a drive letter assigned to the reader which actually amazed me. I had to run "Refresh Removable Media" object located in the "Drives folder" first though (This is the same as typing

LVM /RediscoverPRM

at a command prompt). Unfortunately I could only read files from the CompactFlash cards, but not modify or delete them. When I tried newer versions of the USBBASIC and USBMSD driver the drive was no longer recognized after that change.

I then tried it on my Dual Pentium Pro workstation which has an old Intel chipset, so it uses the UHCI USB driver. With that setup the reader wouldn't get a drive letter assigned to it at all. I tried different versions of the the relevant drivers, but no success. I downloaded Chris Wohlgemuth's USB MSD driver from hobbes which I heard worked better then IBM's but still no luck.

I downloaded the USB Resource Manager from the Netlabs site. This is a great utility for showing what USB devices are attached to your system and some details about what they report to the system. It will show all USB devices, not just storage devices.

Right click on a device and select View device report to see information that the device reports to your system.

So I knew the Sandisk reader was being seen by eComStation. I went on Usenet and asked if anyone could tell me what was going on. One of the more informative posts was by the USBGuy, Markus Montkowski, who is also the author of the USB Resource Manager. He told me that these multi-reader devices used the LUN concept (Logical Unit Number), which is from the SCSI world, and allows a single physical device to have more then one device ID assigned to it. According to Markus, the OS/2 USB drivers did not support this ability. The fact that I was able to recognize the CompactFlash reader in my Sandisk multi-reader was just a matter of luck, as that must be the initial device. Possibly this capability will be added to the OS/2 USB driver, but for now, this Sandisk multi-reader didn't seem to be of much use under OS/2-eComStation. It would be of no value to anyone who needed to read SmartMedia.

So I turned to Usenet to see what if anything others had found did work well with OS/2. This time I was specifically looking for a CompactFlash only reader. A couple of folks had success with a PNY USB CompactFlash reader. So I went back to my local Staples store and found they had one for of these PNY CompactFlash readers for about $20US as well as a similar USB SmartMedia reader as well. The PNY included a 1 meter long USB cable.

I tried this first on my Toshiba Satellite with the OHCI driver and could not get a drive letter assigned. USB Resource Manager showed the device was there, but no matter what driver I tried to use, it wouldn't work. Next I tried it in my Dual Pentium Pro workstation and it was recognized right away after running LVM /RediscoverPRM, I was able to read CompactFlash cards as well as delete and modify and write new files. Unfortunately I really needed this on my laptop, so that when I was traveling I could transfer photos from my Nikon CoolPix 950 camera. I had bought this camera a couple years ago specifically because it had a serial transfer capability, but that is painfully slow compared to directly reading files off of a CompactFlash card.

Well finally with the purchase of a new laptop, my problems seem to be solved. My Medion MD7275 has two USB 1.1 UHCI ports. The PNY USB CompactFlash reader works well with the latest USB UHCI driver and USB Mass Storage driver available from the eComStation website.

Having tried this CF reader in windozeXP, one nice feature noted was that the card was recognized and assigned a drive letter as soon as it was plugged in. Well guess what? That feature is available for OS/2 with just a tiny bit of work. On hobbes is a small utility called USBMOUNTD. I downloaded this, unzipped it to a directory, created a program object (with a -s parameter and set to start minimized) and put that in my Startup Folder. Now whenever I boot into OS/2, this utility checks to see if a USB removable disk is connected, and if so it refreshes LVM so a drive letter is assigned to it. As it is running as a daemon, it will refresh LVM whenever a USB storage device is inserted, so it doesn't have to be inserted on boot. Now I can insert, remove (after ejecting the drive), and re-insert a new card, without rebooting. This utility requires the USB Resource Manager (mentioned above) installed and the

DEVICE=F:\Utils\USBResMgr\usbresmg.sys

from that package loaded in your CONFIG.SYS file.

Some things to keep in mind when dealing with USB Mass Storage devices.

You have to install the correct USB Basic driver for your USB controller and you need to have a driver for each controller in your system. My new laptop has two USB 1.1 UHCI controllers, so I have the
```
DEVICE=USBUHCD.SYS
```
driver listed twice in my CONFIG.SYS file.
If you have more then one type of USB controller, you need to have a driver for each. I don't have any USB 2.0 controllers, but I have read that that these usually have some sort of USB 1.x controller as well, so you have to make sure you have either the correct OHCI or UHCI driver loaded as well.
Unless you have a USB floppy, add the
```
/FLOPPIES:0
```
to the
```
BASEDEV=USBMSD.ADD
```
driver line in your CONFIG.SYS file. This driver defaults to assigning two drive letters for USB floppies. That's two driveletters reserved whether you use a floppy or not. It had me confused when I initially installed the USB MSD driver, since I kept thinking these drives were my USB card reader.
Make sure you eject a USB drive before actually unplugging it. You can do this by either typing
```
eject X:
```
at a command prompt or by selecting Eject disk from the right mouse click menu on the USB drive object in the Drives folder. Failure to do so may cause data loss.
Since you can read and write directly to the media from any application or even the WPS, keep in mind that any direct updating of files may cause EAs to be written to the drive which is FAT formatted. I found that using PMView to create thumbnail images, left them unreadable under OS/2 when I next had to read the card, with the system saying "SYS0278: The system cannot find the extended attribute". All the files were still readable in the camera and under windoze, but not under OS/2. CHKDSK /F fixed the problem for me when I finally thought to try that, but prior to that I had ended up reformatting the card in my camera to use it again under OS/2. That of course caused me to lose the image files.
Finally you can use these CompactFlash readers as general removable media as well, since you can write to them as well as read from them. I wrote this article on my laptop and since I don't have LAN networking setup through my wireless router yet, I needed a way to get the article and the images from the laptop to the workstation. I just inserted one of my CompactFlash cards into my laptop and copied all the files, and then moved it over to my workstation and copied them into the newsletter directory to build the article. CompactFlash cards can be found in sizes up to 512MB at present.

Three types of USB (Universal Serial Bus):

EHCI - Enhanced Host Controller Interface. A unified format for USB 2.0, also called Hi-Speed USB. USB 2.0 supports target speeds of 480 Mb/sec, 12 Mb/sec, and 1.5 Mb/sec.
OHCI - Open Host Controller Interface. USB 1.x format used by chipsets other then Intel and VIA (such as Opti, Ali, Sis, and others)
UHCI - Universal Host Controller Interface. USB 1.x format used by Intel and VIA chipsets.

References:

Other links referenced:
  Review of the IBM Travelstar 8E PCMCIA drive - http://www.os2voice.org/VNL/past_issues/VNL0802H/vnewsf2.htm
  eComStation website - http://www.ecomstation.com
  IBM's Software Choice - http://service.boulder.ibm.com/asd-bin/doc/en_us/catalog.htm
  Hobbes USB drivers - http://hobbes.nmsu.edu/cgi-bin/h-search?key=USB
  OS/2 World USB site - http://www.os2world.com/usb
  Toshiba Satellite 2545XCDT Laptop - http://www.os2voice.org/VNL/past_issues/VNL1099H/vnewsf6.htm
  USB FAQ - http://www.usb.org/faq/
  SanDIsk Dual Card USB reader - http://www.sandisk.com/consumer/dualslot.asp
  USB Resource Manager - ftp://ftp.netlabs.org/pub/usb/usbres.zip
  PNY USB CompactFlash reader - http://www.pny.com/home/products/card_reader_index.cfm
  USBMOUNTD - http://hobbes.nmsu.edu/cgi-bin/h-search?key=USBMOUNTD

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