One way to do this would be to make a basic PC emulator, with CGA (320x200x16) graphics - as that's the only old standard that would fit, sound blaster 8 emulation, base 640K RAM - you know what I mean - the standard PC from around 1990.
However, having said this, there are very few emulators on Android. I can only find SNES, Gameboy Advancedm Gameboy Colour, TurboGrafx, Chip-8, and C64 emulators.
There's not even a Sinclair Spectrum emulator out there, and the clue is in the C64 emulator description where it says "runs very slow" - even though it does play Elite(!!!).