The 9600,5,n,1 error message is most likely only a side effect.

- Try a DOSBox SVN build (something has been fixed)
- Try a non-USB serial port
- Try different settings for cycles

Serial port hacks that use strict timing to emulate other protocols generally have difficulties running in DOSBox as it is not a realtime system.

Thanks for the response, hal.

I did try your MegaBuild (MB5) and there was no difference. Same errors.

Unfortunately my PC only has USB ports and the dongle I've got is also USB, not a serial dongle with a USB adapter. I was hoping a virtual COM port would do.

Any suggestions on what cycle settings to try? Or is there at least a link that has better info for me to read more about these settings (I'm not that well versed on the subject)?

MB5 is quite old and does not include the fix.

Good to know. Back to v0.74 then.

I just noticed that my virtual COM1 does not use an IRQ. Would this cause an issue if DOSBox or whatever program I'm trying to use expects an IRQ?

It's an FTDI Chip based deal, if that helps. Would be interesting to know if there are other people who have successfully used other FTDI-based converters/drivers in DOSBox.

The FTDI converters work better than the Prolific ones (driver bugs). There are a few settings in their device properties to play with, that is if you don't use a virtual serial port after all.
The IRQ is emulated internally so no need to worry about. IRQs inside DOSBox have nothing to do with those outside. 0.74 doesn't include the fix either, you need a SVN build.

Again thanks for the quick response. Appreciate the input.

Just tried the latest emucr SVN build, no such luck.

Only settings I see I can play with on the USB Serial port in Device Manager are as follows:

bps: 9600
Data bits: 8
Parity: none
stop bits: 1
Flow control: none

There's an advanced button, but it doesn't look like changing much in there would help.

DubDude wrote:

Only settings I see I can play with on the USB Serial port in Device Manager are as follows: […]
Show full quote

Only settings I see I can play with on the USB Serial port in Device Manager are as follows:

bps: 9600
Data bits: 8
Parity: none
stop bits: 1
Flow control: none

There's an advanced button, but it doesn't look like changing much in there would help.

All of this won't do a thing for you. It only sets the defaults used by those programs which don't bother setting their own values - such as some serial printer drivers. DOSBox is not one of these programs, so you will need to set up the right communication parameters inside the Application you're running in DOSBox. DOSBox then forwards the settings of its internal emulated COM port to the real Windows COM port driver.

Thanks for the response. I suppose it's just a matter of a little trial and error, then. I know I can change which COM port it attempts to use as well as bps and a couple other things in the program itself.

I tried changing the bps, it just changes the first digit in the error that shows up in the DOSBox console window.

So I shouldn't have to set any additional parameters in DOSBox other than serial1=directserial realport:COM1 theoretically? I've searched and noticed a few people setting some manual parameters for IRQ (which I now know won't be required for my case), bits, bps etc.