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Re: Building an Apple II from scratch



Nearly 20 years ago several friends and wirewrapped quite a number of
Apple ][+s. Of course we used the same chips as Apple did but it would
be a good project. The circuits timings would probably be the critical
part. In our experiments the chip types LS, S and so on were required
in the correct positions.

Bill

On 14 Jul 2003 16:57:21 -0700, great_hierophant@hotmail.com (Great
Hierophant) wrote:

>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?
>
>GH