salzman@NMS.HLS.COM (Mike Salzman) (09/26/90)
As long as extensions to the basic spec are brought up..... Roger Fajman is correct in stating that the original specs were documented in the AT Tech Reference. Aside from Bridge, others have added extensions to the interface because it was so brain dead. A common addition, first instituted by Walker, Richer and Quinn provided a function call to initiate a BREAK at the port. UB developed a completely different interface, INT 6B, for handling blocks of data more efficiently across a network connection. The problem (dillema) with interfaces is that a different code module is required in each case, since the mechanisms are so different. However, the original notion that INT14 would allow a package to operate in a real PC, out the serial port, or over a network connection, is not credible. As any one who has tried it knows, even an AT can barely keep up with a 4800 baud connection on the port, if they use the BIOS interrupt. Most software interfaces directly to the 8530 chip, and bypasses BIOS. -- -------------------- salzman@hls.com ---------------------- Michael M. Salzman Voice (415) 966-7479 Fax (415)960-3738 Hughes Lan Systems 1225 Charleston Road Mt View Ca 94043
assg7@tnofel.fel.tno.nl (Rene van den Assem) (09/26/90)
From the discussion about INT14, I understood that there exists an extension to the normal INT14 for the serial ports on XT/AT/PS2. Has anyone such a specification available? I'd like this because I would like to make an INT14 handler for a TCP/IP package. Rene van den Assem, TNO Physics and Electronics Laboratory, The Netherlands, +31703264221, assem@fel.tno.nl
RAF@CU.NIH.GOV (Roger Fajman) (09/30/90)
> From the discussion about INT14, I understood that there exists an > extension to the normal INT14 for the serial ports on XT/AT/PS2. > Has anyone such a specification available? > I'd like this because I would like to make an INT14 handler for > a TCP/IP package. The definition of INT 14 is in the IBM Tech Ref manual for the PC/AT. There were extensions to INT 14 defined for the PS/2. Those are described in the IBM PS/2 BIOS Tech Ref manual. There are also 3rd party sources, such as Peter Norton's book, Inside the IBM PC and PS/2. Bridge Communications (now part of 3Com) defined their own extension to INT 14 called BAPI. The description of that is in their manuals on products such as PCS/XNS and 3+Open XNS. The extensions provide the ability to transfer blocks of data instead of a byte at a time. They also provide a call for generating a break signal, which is missing from the original INT 14 spec, but is in the PS/2 spec.