Quote:
Originally Posted by Ether
I haven't had a chance to do this yet, but my plan is to make an RS232 cable to connect the DOS machine's COM1 port CTS pin to the RTS pin of my machine-under-test (XP) which is running the RTS toggler I posted here. |
OK I did it:
XP machine running a process which toggles the COM1 RTS pin at 50Hz 25% duty cycle (5ms ON, 15ms OFF).
Null modem cable connects the COM1 port of the XP machine to COM1 of a Gateway 9550 laptop booted to FreeDOS and running an app which timestamps
* the rising and falling edges of the signal on its COM1 CTS pin.
Attached is a plot of a portion of the data.
*with a 1.13 GHz counter