This file is just provided as input to the print samples included. Please refer to DOSUSB.HTM for the DosUSB driver documentation! DOS support for USB is currently very limited. There are only a few drivers available, e.g. for mass storage devices. DOS can work with a USB keyboard and a USB mouse only if the BIOS features legacy support by doing a 8042 controller emulation for these devices. With legacy support enabled, the BIOS will then also support to boot from and to access a USB floppy drive or hard disk. For Linux there are UHCI, OHCI and EHCI drivers available and a lot of device drivers which are based on these USB controller drivers. Using DOSUSB.COM it is now possible for DOS application programs to communicate with all sorts of USB devices and to implement USB device drivers for DOS. DOSUSB.COM is a USB host controller driver for DOS. It is a TSR program which implements a universal host controller driver (HCD) and a universal serial bus driver (USBD). It can also be used with WIN 3.11. DOSUSB.COM provides a software layer so application programs and USB device drivers can be written supporting specific USB devices. It builds frame lists for the USB host controllers, sets up transfer descriptors and queue heads and schedules the transactions requested by the USB device drivers. To start DosUSB enter DOSUSB.COM at the DOS prompt. DosUSB will then enumerate all the connected devices and install itself as a resident program. On laptops, the number of ports per controller may exceed the number of USB sockets installed. DosUSB will then show more ports than can be used with devices. DosUSB itself requires about 23k of computer memory. However, it also requests additional memory for each controller installed in the computer. DosUSB will work on a computer featuring UHCI or OHCI controllers. It will try to determine whether OHCI or UHCI controllers are installed and report this. If the PC has an Intel or VIA mainboard it will have UHCI controllers. These mainboards are used in most computers. If the PC has an EHCI controller for USB 2.0, DosUSB will still be able to run, since the EHCI controller works together with UHCI or OHCI controllers which DosUSB can use.