Readfile
Readfile utility calculate CRC32, Adler32, MD5 and SHA1 of fille. It allows you to test the speed of memory copy and disk transfer operations under Windows 95 and Windows NT. This is a Win32 console application. C Source included.
http://www.winimage.com/readfi16.zip - 484Kb - Download

AVSD OEM
AVSD OEM is a programming interface, which allows you to add support of virtual serial ports to your own application. You have full control over ports created with the help of AVSD OEM, including reading data that some other application has written using WriteFile function, writing data to be... With AVSD OEM you can: -Create your_protocol-to-serial abstraction. ... -Create virtual platform and emulator plugins. ... And vice versa, you monitor all data coming from device and redirect it to the virtual port.
http://www.virtualserialdriver.com/files/avsd_oem.zip - 448Kb - Download

Multicom OEM
Multicom OEM is a programming interface, which allows you to add support of virtual serial ports to your own application. You have full control over ports created with the help of Multicom OEM, including reading data that some other application has written using WriteFile function, writing data... With Multicom OEM you can: -Create your_protocol-to-serial abstraction. ... -Create virtual platform and emulator plugins. ... And vice versa, you monitor all data coming from device and redirect it to the virtual port.
http://www.intellidriver.com/downloads/products/multicomoem.zip - 448Kb - Download