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Linux guest

Marco Bortolin edited this page Aug 28, 2025 · 3 revisions

Requirements

IBMulator version 0.15 or later is required.

Compatible Linux distributions

The only tested distribution is Monkey Linux v06 with kernel version 2.0.30

Floppy drive

The PS/1 floppy drives use an inverted convention for the disk change line, so this Linux kernel parameter must be used:

floppy=thinkpad

Alternatively you can set:

[drives]
fdc_mode=pc/at

in ibmulator.ini, but this would render the FDD unusable in DOS.

The HLT instruction

Old Linux kernels used the HLT instruction to put the CPU into a low power state, while enabling interrupts to wait for any event.

IBMulator's virtual CPU can't just wait for external interrupts and the emulator must still simulate the passage of time during the "execution" of HTL.

The [cpu]:hlt_wait in ibmulator.ini will let you set the amount of time in nanoseconds an HLT instruction takes to "execute". The lower this value, the faster the reaction time is to an interrupt, but at the cost of making the emulation computationally very expensive. The default value is 500, which seems to be a decent compromise.

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