DOS inside Win98 extremely slow graphics

Hi,
I'm running parallels desktop (5608) and have installed win98, manually adding the graphics and mouse driver.
The speed of Win98 seems ok, but I have a vertical DOS application with graphics (640x480 full screen) and when I launch it it has extremely slow screen refreshes.

My computer is a Mac mini Core 2 duo 2 Ghz with 1GB RAM (512 for the virtual machine).
It replaces a VERY old pentium PC that strangely enough was a lot faster running that DOS application.

Am I missing something ?
Is there a better way of running a DOS application. Should I tweak in some way the graphics settings ?

Thank you

Carlo

 

Maybe you're better off using DOSBox (it's a DOS emulator), it has an OS X port.

Here's a screenshot.

 

Good idea, I'll test it, but does it have network support ? The application is on a server.

 

Maybe just to install DOS portion of Windows 98 and select DOS as OS, RTL(NIC) drivers are available for DOS