I want to use DOSBox to access COM1 under XP using direct peeks and pokes to the UART's registers. When I try this in Windows compatability box, transmit works fine, but the program hangs when transmit is looped-back to receive. When I try this with DOSBox, the program runs real good, but nothing is transmitted.
DOSBox doesn't really use COM ports. It actually uses IP addresses and ports and fakes the game to think the COM port is real.
So when you play the game between two computers, you actually connect through TCP/IP and not the real COM ports.
DOSBox supports all the outdated connections - serial COM connections, modem COM connections and IPX lan. It transfers all of them (update - read: the latter two) into the modern TCP/IP connection.
TCP/IP, of course, is the technology of the Internet.
In other words: it's as if the DOSBox authors hacked into the games and added TCP/IP support...
wrote:DOSBox doesn't really use COM ports.
Wrong. There is a possibility to directly access a serial port from DOSBOX in Windows. As CANADACOW said, only direct access is supported, not BIOS functions.
Did you allow the direct access (see [directserial] in DOSBOX.CONF)? It is switched off by default.
If it still does not work (after checking that it is allowed), then I do not know (probably CANADACOW would know more - he checks this forum occasionaly, so maybe he will answer).
Mirek
Wait a minute, some games need modem access and some serial COM access.
I've always thought "directserial" is for the latter case.
So you say the "modem" setting is for both cases (modem and direct) or just for the modem?
And if I enable both "modem" and "directserial" at the same time and with the same comport, does the world as we know it come to an end?
a) Modem is implemented by TCP/IP tunneling.
b) IPX is implemented by TCP/IP tunneling.
b) Direct serial accesses physicall serial port (Windows only)
d) There is no TCP/IP tunneling for serial port (as you thought)!!!
I do not know what DOSBOX will do with modem and direct serial on the same COM port... At least one (or both) will not work.
Mirek
Hmm, you've summed it up pretty good...
I stand corrected (and corrected some mistakes in my previous posts).
But speaking of which, how come the DOSBox authors decided not to tunnel serial COM connection into TCP/IP, like the other two connections?
Of course, it wouldn't have to replace direct access because they could just replace "directserial=true/false" with "directserial=none/direct/tcp" (I'm sure you get the picture).
Is it because they've come to the conclusion that all (or most) games which support serial COM connection also support modem COM connection anyway?
wrote:But speaking of which, how come the DOSBox authors decided not to tunnel serial COM connection into TCP/IP, like the other two connections?
...
Is it because they've come to the conclusion that all (or most) games which support serial COM connection also support modem COM connection anyway?
Yes, it was viewed as not worth the effort. Saying that - anyone can volunteer and submit a patch...
Mirek