I'm in the process of repairing an Otrona Attache I picked up last summer. When received, it needed some monitor adjustment but did initially display an error about wanting a boot disk. After monitor adjustment, I was attempting to get it into temrinal mode and it randomly failed to come up after a reboot.
I had some time today to try and troubleshoot it a bit. I replaced the boot ROM with a HALT ROM (0x76 at every location), and the processor does indeed halt on power-on and reset. I dumped the boot ROM and disassembled it...seems there's some amount of corruption in the ROM, as the routine it jumps to from 0x0000 never returns and disables interrupts.
Does anyone have an image of the Otrona ROM? I'm also looking for a copy/scan of the user's manual, as apparently the ROM has some diagnostics routines as well as bootstrap/terminal mode. I'd like to have at least terminal mode up and going before VCF.