Both. You can buy trainers with old chips like this, z80, CDP1802, 8080, 6509 etc. The main advantage of the new SBCs is simplicity vs anything more modern an

Both. You can buy trainers with old chips like this, z80, CDP1802, 8080, 6509 etc. The main advantage of the new SBCs is simplicity vs anything more modern and easier to deal with than a retro computer. The advantage of a retro computer is it has some intrinsic value and probably a large body of contemporary software.