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From: Lawrence D'Oliveiro <ldo@nz.invalid>
Newsgroups: comp.arch
Subject: Re: Whether something is RISC or not (Re: PDP-8 theology, not
 Concertina II Progress)
Date: Tue, 16 Apr 2024 00:35:06 -0000 (UTC)
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On Sun, 14 Jan 2024 14:30:51 -0500, EricP wrote:

> Furthermore, the address and data registers and buses are 16 bits and
> the high 16-bits are shared ...

No, in the 68000 family the A- and D- registers are 32 bits.

If you compare the earlier members with the 68020 and later, it becomes 
clear that the architecture was designed as full 32-bit from the 
beginning, and then implemented in a cut-down form for the initial 16-bit 
products. Going full 32-bit was just a matter of filling in the gaps.