Most hard realtime control systems don't use FPGAs but hard processors. I don't relaly believe those can't achieve as good timing control as a pdp11. EDIT: Fro

Most hard realtime control systems don't use FPGAs but hard processors. I don't relaly believe those can't achieve as good timing control as a pdp11. EDIT: From the FPGA vendor: > Double+ speed Osprey Co-Processor. Occupies one ISA/EISA PC slot. Writable control store, FPGA implementation of PDP-11 architecture with 4 MBytes of tightly coupled, zero wait-state memory. Includes FPJ11® compatible hardware floating point. Performance equivalent twice the DCJ-11® and 100%; of FPJ-11. On-card x86 microprocessor rapidly processes "virtual" I/O instructions. This card is used for Osprey/PC applications where all applicable I/O devices are emulated on the PC by Osprey software. Includes standard environment support for MS-DOS® V6.2.2. Windows/NT® environment support available. So, highly unlikely that such a system using standard x86 PCs with all their SMBIOS traps and other garbage is able to emulate IO could possibly drive external IOs with better precision and accuracy than a proper real time SOC. Cycle accuracy may be a requirement in the processor such that legacy software is guaranteed to run the same, but they almost certainly are not doing cycle accurate IOs if they're going across an ISA bus to a DOS or NT PC to be emulated there.