Hi,

although you possible don't care: Neither Interrupt 19h, nor Interrupt 18h nor jumping to the address 0xF000:0xFFF0 from within DOSBox does the trick to "reboot" (for DOSBox: just restart or, even more easy, close) the machine.

Both Interrupt 19h and Interrupt 18h just return. For Interrupt 18h, this is probably okay. Interrupt 19h however mustn't return but shutdown the machine - whatever this requires.

At the mentioned usual "cold" reboot address there's no jump opcode as in real BIOSes but just (zero) data. DOSBox indeed manages it to hang (and cause a host CPU load of 100%, as usual) on the jump. Ever heard from Interrupt 06h? Some of the invalid opcodes there would cause one on real machines (or serious emulators). If Interrupt 06h was however generated and DOSBox failed to show it correctly, it's either a DOSBox fault.

It's actual a Box now and it runs some games, but where's the DOS?