I heard from someone when you installed the game from the original setup, it would ask for joystick calibration!

So I tried it, It does! I noticed it alters the command line to support joystick! So that's why Megarace 1 didn't work with joysticks before!

Open dosboxmegarace.conf using notepad (usually inside C:\Program Files(x86)\GOG.com\Megarace\Megarace)

On the end of the file it'll be like (if you see any part different from mine, don't bother changing, just add the different part):

@ECHO OFF

mount C "." c:\

cls

RACEPRG ENG ADP220 SBP2225 EMS WRIC:\

Then, add "JOY0000-0000-0000-0000" before EMS so it's like:

RACEPRG ENG ADP220 SBP2225 JOY0000-0000-0000-0000 EMS WRIC:\

The numbers would vary from the calibration on the setup, all zeroes mean it's perfectly aligned, you can just calibrate your Joystick on Windows and you'll be fine :). Joysticks should be working now!

Ah! You can also add NOM before the JOY command to disable the mouse-controlling ability!