Revision History


          The following changes/additions were made in internal build
          0.113.

               The initialization procedure for enabling the FIFOs of the
               16550 was changed as per directions from StarTech.  The
               StarTech 16550 is used in many Practical Peripherals modems. 
               This change may correct overrun and hanging problems for
               other users.  User reports indicate that the FIFOs
               initialization problem may go beyond the StarTech 16550 and
               thus, solve problems for users of other 16550s.

          The following changes/additions were made in internal build
          0.114.

               Additions to force enabling of comm ports for VMBs under
               2.1GA.

               Version number was changed to à1.01

          The following changes/additions were made in internal build
          0.115.

               The Interrupt Service Routine (ISR) was improved to insure
               that all pending interrupts of all ports sharing the same
               IRQ are serviced.

          The following changes/additions were made in internal build
          0.116.

               Additional changes to decrease the processing time of the
               Interrupt Service Routine.

          The following changes/additions were made in internal build
          0.117.

               Additional information added to the boot time banner.

               Changed the version number to 1.02.

          The following changes/additions were made in internal build
          0.118.

               Corrected erroneous sending of XON when receive flow control
               was enabled.

               Added code to clear the UART's FIFOs during initial file
               open.








          The following changes/additions were made in internal build
          0.119.

               Corrected a problem with hardware flow control for DOS
               processes.  This problem showed up most often in windowed
               DOS programs.

               Removed code specific to the March, 1993 beta of OS2.

               Added support for installable and removable communications
               devices, eg PCMCIA.

               Some users of VX00 will see improved performance from FOSSIL
               aware DOS programs.

          The following changes/additions were made in internal build
          0.120.

               Code added to allow I/O port mapping to DOS sessions.

          The following changes/additions were made in internal build
          0.121. 7/28/93 14:00pm

               Corrected a problem that would cause the system to hang if
               an SIO command line error was detected.

               Additional code added for "hot plugging" of PCMCIA comm
               ports.  Users of PCMCIA comm devices should not remove those
               devices while a comm program active.  Many comm application
               programs can not cope with the modem being removed.  Your
               system may lock up if you remove a modem while a comm
               application program is active.

               Changed the way virtual CTS is handled.  In previous
               versions, the virtual CTS was always on.  Under appropriate
               conditions, the virtual CTS will now be turned off.

          The following changes/additions were made in internal build
          0.122. 8/14/93 14:20

               Corrected a problem in the internal (to SIO) shared
               interrupt chain.  This problem would cause the system to
               lock up when the third device checked in on the same IRQ.

               Added command line options for PCMCIA.








          The following changes/additions were made in internal build
          0.123. 8/18/93 19:05

               Added code to wake sleeping receive threads when a Flush
               Input command is received.  This additional code allows HA/5
               Version 3.1 to work with SIO.

               Changed the version number to 1.10 and released it for
               downloading.

          The following changes/additions were made in internal build
          0.124. 8/28/93 14:50

               Corrected a serious error in SIO.  This problem could show
               up in almost any way.  The most common symptom is/was trap
               000e and inordinate processor overhead when comm is active.

          0.125. 9/09/93 08:15

               Nothing yet.