The American keyboard should give you the plus sign with SHIFT and the key to the left of BACKSPACE. Looks like the Japanese keyboard has an extra key there - might want to try SHIFT and each of the keys between the 0 (zero) key and BACKSPACE.

What value do you have in dosbox config file's keyboardlayout= under the [dos] subsection? Keyboardlayout=none gives me the American layout in Dosbox (I've got a Finnish keyboard).

If those don't work, you can try the keymapper (CTRL-F1). Click on the key to the left of BACKSPACE (which is above and to the left of the ENTER key). It tells you which key on your real keyboard is bound to that key. You can change it by deleting the old one or you can add a new bind by clicking Add and hitting your favorite key on your keyboard. If you want to make that bind permanent, click save before clicking Exit. Try it on the prompt - SHIFT plus that key you just bound should give you a plus sign provided that you've also set keyboardlayout=none.

ripa, here is an answer to one of your questions:
under the dos subsection the keyboard layout setting is:
keyboardlayout=auto

I have been playing with the keymapper, I have it so screwed up now that I will have to truncate the mapper.txt and try again.

Thank you ripa; problem solved. I set keyboardlayout = none and mapped the plus key as you said and now the game runs perfectly. Thanks very much for your help.

As far as I remember, keyboard layout was a problem with a spanish 8086 PC. The solution was using the english layout (in DOS you could switch to english keyboard with CTRL+ALT+F1, and back to your country keyboard using CTRL+ALT+F2).

I still use that keys when I find a misconfigured windows (I'm spanish, but some windows installs with latin keyboard rather than spanish keyboard) to use the symbols that I don't know where are hidden.

Note: i think the game needs "=" key not "+", so you should have looked for = on your keyboard

My problem was basically the same, only it was a US Keyboard on a laptop. My solution was on the Keymapper (DosBox 0.74).

• Go to the KeyMapper
• Make sure Numlock is on, on your keyboard
• click the = key on the keyMapper
• click the "add" button on the keyMapper
• type the + key on your keyboard's Keypad
• click the "next" button on the keymapper until the bind indicator shows "key ="
• click the "del" button on the keymapper
• click the "keypad +" button on the Keymapper
• click the "next" button on the keymapper until the bind indicator shows "key {+}"
• click the "del" button on the keymapper
• click the "save" button on the keymapper

This will set your = key next to your backspace to begin typing +. Consequently your + key on your keypad will begin typing =. Somehow this correlates to enabling the use of the keypad plus key as the + key in dos games. Don't ask me how, but it works.