Tag Archives: usb 3

Arca Noae progress report: USB, ArcaOS updater, multimedia

Here are some of the recent happenings around the Arca Noae labs and design studios:

We’ve recently made significant progress toward localizing various parts, particularly for German and Spanish, and will soon have a new test build of the CWMM classes in Spanish (a completely new translation for this component).


We continue to improve the update process for the next ArcaOS release, as we find edge cases where the current updater doesn’t quite finish due to unexpected conditions in the target system. (As a reminder, please check the ArcaOS Updating wiki page before beginning an update to the latest release. There you’ll find hints and tips to help avoid – or resolve – some known problems.)


When IBM left off USB driver development, OS/2 had a working, 16-bit USB 1.x and 2.0 driver stack. Fast forward to 2019, and this is no longer adequate for the needs of today’s hardware.

The Arca Noae USB stack is now fully 32-bit, and USB 3 support development continues to make good progress. Implementing USB 3 support has been tedious because the OS/2 USB architecture didn’t accommodate the peculiarities of USB 3 well.

Adding USB 3 support was not as simple as just writing a new xHCI driver. Significant changes were required throughout the entire USB stack, including changes to USBD and the OHCI, UHCI, and EHCI drivers. The xHCI driver as it exists today in beta testing works quite well. There are just a couple of things that still need to be done before we will be able to release it for general availability. One thing is to implement support for Isochronous transfers (audio and video devices). The second thing is to improve the error recovery speed. Error recovery speed was not an issue with USB 2 because USB 2 devices rarely, if ever, had errors. Super Speed (USB 3) devices operating at the new USB 3 speeds have higher error rates so the error recovery speed is important. We are actively working to resolve these last two issues.

Once the xHCI (USB 3) driver is released, the Arca Noae USB stack will make it possible to install and run ArcaOS on systems which lack USB 2.0 (EHCI) controllers. (Even though many modern systems advertise the availability of USB 2.0 ports, these ports are indeed wired to xHCI controllers. Without an xHCI driver, this will result in loss of keyboard and mouse control shortly after boot and the inability to mount the installation ISO from USB-attached media.)


Don’t have ArcaOS yet? Now is a great time to pick up a license or two and replace that aging Warp 4 or eComStation installation and get to know what’s new and improved. ArcaOS supports more modern hardware than any other OS/2 distribution available today, making hardware upgrades much easier than ever before.