I just got the blaster and I can't fire it in order to proceed and destroy those mechs.
Controls say that the fire key is numeric 5, but I don't have a numeric keypad on my laptop.

Is there another way to fire the weapon, any other key?
Controls say that sidestep is done by numeric 1 + 3 but Page Up - Page Down keys do the exact same things.
What about fire?

you can always remap controls by opening the built in key mapper that Dosbox has, just hit ctrl+F1 and remap the keys you need to whereever.

I tried this but it doesn't seem to work.
I pressed Ctrl+F1, went to keymapper and changed num5 to another key.
Saved the new setting but when I started Bioforge the new key didn't work. No response.
What did I do wrong?

okay in the mapper did you click on num5, deleted the current binding which would be key [5] and then add the new key first?

if not do that, then click the key your going to use for the fire button and delete it's current binding(by clicking del)

I did that but still no luck.
Also I tried binding a key from those that already work on another key, for instance I left the "up" to the "up" cursor key where it originally was and binded "q" as "up".
I pressed "q" with a hope that he'll move forward but nothing happened.
Maybe keymapper doesn't save my settings when I'm done and proceeds with it's default settings.

hmm, I tell you what let me know what key's you want the game to use and I'll go into my game, do the mapping and then send you the mapper file.

I tried different keys but none of them worked.
Try to set the fire key (default is num5) to Q.

There's something else I couldn't figure out. In the keymapper there are four buttons that say "mod1", "mod2". "mod3" and "hold". What are these for?
From the info I gathered these refer to combinations, like Ctrl + arrows in Bioforge to kick left, right, headbutt or roll back.
The "hold", I don't know what that is.
And "mod3" seems to be empty by default.

No clue on the mod buttons but try this: http://www.fileswap.com/dl/2J4XNUVS1/ just place the file(mapper.txt) in the Bioforge directory(the one with the dosbox.conf's)

Have you tried this mapper file? From what I see you've binded 5 for fire. When you pressed 5 did he shoot? Cause with me still nothing happens.
Is there something special I have to do to shoot my weapon?
From what I see in the manual when you press num5 he's supposed to use the weapon. And since num5 is binded with 5 this should work. Why doesn't it works?

What? no I binded Num 5 as Q, I had to select the num 5 key and set it as Q in the mapper or it would not work, as you asked try Q and see if it works

Wait, I copied mapper.txt and paste it 3 times in both DosBox, original Bioforge files and Bioforge Gog files folders. Somehow I got it to work.
I had this file in the DosBox folder where I assumed it stored the configurations, but it didn't work.
Probably the mapper file has to be stored in the primary Gog Bioforge folder.
Is that right?