I was quite surprised how difficult it is to set a serial port (COM1, the used I/O card has a working 16550 UART) to a baud rate of more than 9600 baud - all done with an original IBM PC/XT.
I figured out that the BIOS itself (NOT the used DOS 5.0) prevents to set more than 9600 baud (at least with programs which uses INT 14h).
But even (external) commands/programs for my Wilke Tech. SA-20 Eprom programmer (SA.EXE) which have a build in setup for the serial port do NOT work with higher baud rates.
Unfortunately if I am using some utilities like TOADMOD1 to set the port (I could check the result by MSD) to 19200 baud, the main program SA.EXE itself changed the baud rate in a way, that the new settings (like 19200) don't work.
I've looked also for a BIOS extension (INT 14h replacement) program, but it seems this is impossible - I've found some programs which claims to extend the INT 14h, but they didn't improve the possibility to set a higher baud rate.
So I'm doomed to use only 9600 baud with an IBM PC/XT ?
I figured out that the BIOS itself (NOT the used DOS 5.0) prevents to set more than 9600 baud (at least with programs which uses INT 14h).
But even (external) commands/programs for my Wilke Tech. SA-20 Eprom programmer (SA.EXE) which have a build in setup for the serial port do NOT work with higher baud rates.
Unfortunately if I am using some utilities like TOADMOD1 to set the port (I could check the result by MSD) to 19200 baud, the main program SA.EXE itself changed the baud rate in a way, that the new settings (like 19200) don't work.
I've looked also for a BIOS extension (INT 14h replacement) program, but it seems this is impossible - I've found some programs which claims to extend the INT 14h, but they didn't improve the possibility to set a higher baud rate.
So I'm doomed to use only 9600 baud with an IBM PC/XT ?