Most of the components in the original Apple II are still manufactured. The character ROM is hard to find. The 16 kilobit DRAMs are definitely obsolete, but n

Most of the components in the original Apple II are still manufactured. The character ROM is hard to find. The 16 kilobit DRAMs are definitely obsolete, but not exactly rare (dozens of millions were manufactured). Since it's mostly 7400 LS TTL logic you can easily substitute a different circuit to replace a missing part, use modern EEPROMs, etc. (Beware of subtle timing issues - you can't always swap a modern CMOS part for a TTL part.) Accordingly, you can still build an Apple II today: https://www.reactivemicro.com/product/apple-ii-rev-0/ https://www.reactivemicro.com/product/apple-ii-rev-0/ Same store also sells a complete kit for an Apple II+ including components, as well as assembled. (Never bought from them, can give no review.) The Apple II may be one of the last computers so-thoroughly documented. Your 1970s era TI databooks for 74xx TTL components will give you a complete transistor-level schematic of the logic. And the 6502 itself has been completely reverse-engineered. So it's possible to know where every transistor in the computer is and what it does. And the machine is just about simple enough, one person can fit it all in their head, mostly.