On 28.6.18 20:52, Gareth's Downstairs Computer wrote:
> On 28/06/2018 18:02, Charlie Gibbs wrote:
>> You should study the PDP-11 instruction set.  The first time I
>> disassembled
>> code that did stuff like this, I was dazzled by its elegance.  The Z80
>> doen't
>> come anywhere near.
>
> Where its successors (68000, ARM) fall down is in lacking the extra
> layer of indirection on all addressing modes.
>
> But a bit OTT in the case of the Data General Nova, where the MSB set
> in an indirect memory reference means keep deferring  :-(

That was common in the minicomputers of that era (late 60's),
like Honeywell DDP-516 and DDP-316, HP 2114, HP 2116 & co.

The PDP-11 was remarkably advanced at that time, as was also
the IBM S/360, but for different reasons.

One of the advanced architectures well ahead of its time was
the HP 3000.

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-TV

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