недаввно искал живые дистрибутивы DOSа. попадались в том числе с поддержкой USB.
DOSUSB:
http://www.georgpotthast.de/usb/ -стек USB для DOS
в том числе там есть "simcom.bas Sample using the SERDRV.SYS device driver for USB/serial adapters"
3.3 Serial port adapter driver
SERDRV.SYS is a device driver for USB serial port adapters. It has been tested with
Prolific adapters and will work with newer versions of these devices. The Prolific chipset
is used by many adapters and you can use USBVIEW or check in Windows wether it is
such a device.
It does not emulate an UART and therefore cannot be used with many DOS serial
communication programs which hook into the serial interrupt to read the data from the
serial port. This device driver provides a DOS device called "SERDRV". It can be opened
like a standard file in DOS. Then you can read and write to this device using DOS read
and write file commands. See the SIMCOM.BAS sample provided. The baud rate can be
selected with a command line option.
This is the first version of this driver. USB serial adapters use vendor defined commands
which are not published. So the driver will not work with any adapter.
и поиск на "USB4DOS" - второй вариант USB стека для DOS.
PS USB не поддерживает обмен между двумя хостами. USB в принципе не расчитано на это,
где то в продаже видел девайс для передачи данных по USB, но не игрался им. и скорее всего он только для WIN...и описание не найти.
