No. The design made it modern. Look at the m68000 (1979) compared with the i8086 (1978). The m68k was 32 bits from the beginning, so while moving from the m680

No. The design made it modern. Look at the m68000 (1979) compared with the i8086 (1978). The m68k was 32 bits from the beginning, so while moving from the m68000 to the m68020 did add some instructions, there were no "special modes" for "backwards compatibility". All binaries that run on the m68000 can directly on the m68020. Add an MMU and optionally an FPU to an m68020 (1984) or just use an m68030 (1987), and you have a fully modern system that can run modern software in 2022. The i80386 (1985) is 32 bits and much more modern than the i8086, but real mode and 386 mode are completely different. Even with this modernization, Intel didn't bother with atomic operations, which is why neither Linux nor the BSDs support the original i80386. To run modern software, you'd need an i80486 (1989).