Re: Building an Apple II from scratch

[mjmahon@aol.com (Michael J. Mahon)]

Great Hierophant observed:

>Yesterday, I took a look at the circuit diagrams and schematics of an
>Apple II found in the Apple II Reference Manual (the Red Book.)  I was
>struck with the number of components used, but also with their
>commonality.  In an original Apple II, there does not seem to be any
>custom chips or devices, unlike the later Apple IIes and IIcs.  Most
>of the Apple II/II+ seems composed of standard TTL logic chips.  The
>6502 CPU can be found.  The ROM, all 12-16KB of it, can easily fit on
>one EPROM.  48KB of DRAM can be done with two chips.   The connectors
>are probably standard.  Of course, one does not have to build a power
>supply  and can use an Apple II keyboard.  So, has anybody ever
>constructed an Apple II mainboard in the way I have described?

Steve Wozniak worked at HP Laboratories, and the Apple II was
constructed from parts available from lab stock (with the exception
of the 6502 itself).

HP at that time encouraged engineers to engage in projects on
their own time, and happily supplied the parts.  Very enlightened.

The result is that the Apple ][ and ][+ are easily constructed from
stock parts, and many were built like this in the early days, when
$1200 was a little steep for a device with $200 worth of parts.  ;-)

-michael

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