Re: Dosbox and Moto software/radios

Jim - K6JM

Your point makes sense.  To the extent that a particular CPS program has CPU timing dependencies in order to work properly, and if you pick a correct speed setting in DOSbox, it really should not matter what the pc’s actual speed might be.  I also suspect a deep old-hardware expert could explain why  the FTDI USB to Serial works as long as  the DOSbox speed setting is correct for that CPS and radio. 


Just proves that actually trying it is the way to go.  My early experiences were only with real serial cables and old and slow pcs bought off eBay.  DOSbox was a great improvement.


   Jim – K6JM


From: <> On Behalf Of Alan Barrow
Sent: Monday, April 13, 2020 3:15 PM
Subject: Re: [Radios] Dosbox and Moto software/radios


On 4/13/2020 4:36 PM, Cepmender via wrote:

Many older radios need a proper sloooow computer actually running DOS and with a hardware serial bus.


Emulators running in Windows (tm) just don't work.

Here's what's odd, I kept hearing that, yet I'm up to about 7-8 different radios of different generations and CPS's that work find fine with FTDI USB to Serial devices and dosbox:

TK-90 (does not need dosbox)

FTL-3100 and similar
VX-1210 (dosbox not needed with newer CPS's)

Other Maxtracs
CDM's (does not need dosbox, but does need FTDI based serial to ttl adapter)

I think most of the "windows emulators don't work" myths are really just issues with the chip in the USB to serial adapter.

I have some non-FTDI based cables that work fine with windows native CPS's, but not with the old DOS based cps's. So there is a reason the ebay cable sellers list if their cable is FTDI based... it makes a difference.

So while I have old notebooks still with "real" serial ports, I have never had to use them. Yep, sometimes I have to try a few different speed settings on dosbox, but usually something between 500-800 mhz 386 equiv works. And it's just Ctl-F11 and Ctl-F12 to make faster or slower. So very quick to get them to read, usually only takes 20-30 seconds to home in on what works. And I keep all my cps and files on my modern computer.

The radio does not know what's attached to the serial port. There are only three issues which can make a difference, and two of them are due to CPS coding:

- Voltage on various HW pins. Most modern (FTDI and newer) based chips are fine in this regard. I think this is the main thing that bites folks, using unknown USB to serial chips
- Dos Software using timing loops that break on faster computers. Dosbox deals with this nicely
- DOS CPS software only supports COM1 and COM2. Easily dealt with in dosbox... You can map any modern serial port to com1 or com2 (or com3/4 if your cps software supports it)

Have fun,




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