Thank you so much everybody. Now works perfectly. You've made an old developer very happy. Ahhhh ... 1996, VB3 ...

I've just installed and run DOSBox 0.74. The default resolution seems to be 640 x 400 pixels but I really need 800 x 600. i.e. 800 x 600 pixels, not just 640 x 400 magnified up. Apologies if this is a simple question, but I've searched high and low and whatever I do I get the original screen but …