B&B Electronics ESCLP-100 - Manual - Manual (Page 17)

QVCOM.SYS provides most of the same DOS settings as IBM's VCOM.SYS. For full
details on these settings, consult the OS/2 documentation or online help. Differences between
the Quatech and IBM drivers are discussed here. It is suggested that these DOS settings be left at
their default values unless necessary.
COM_DIRECT_ACCESS
This setting is ignored (considered OFF) for ports on Quatech non-intelligent multiport adapters using an
interrupt status register and for ports on Quatech intelligent multiport adapters. Bypass of the driver would prevent
proper servicing of the adapter. Do not attempt to use this setting with COM ports using address/IRQ
masquerading!
COM_SELECT
This setting has been expanded to allow any port from COM1 to COM32 to be selected. "ALL" and
"NONE" are also supported.
COM_HOLD
No changes.
COM_RECEIVE_BUFFER_FLUSH
The IBM OS/2 2.1 release included this new DOS session setting in VCOM.SYS. The Quatech
QVCOM.SYS driver does not implement this DOS setting.
3.4 Interrupt Sharing
The device driver generally supports sharing of interrupts for serial ports adapters
operating in hardware environments "friendly" to shared interrupts.
3.4.1 PCI bus
PCI bus computers inherently support the sharing of hardware interrupts. The device
driver requires that the interrupt status register be enabled. Interrupts are shared by all of the
serial ports on a given adapter. Interrupts can also be shared by multiple adapters.
Quatech Asynchronous Serial Device Driver for OS/2 14