Re: Why VAX Was the Ultimate CISC and Not RISC

On 3/2/2025 12:39 PM, BGB wrote:

On 3/2/2025 5:46 AM, Anton Ertl wrote:

BGB <cr88192@gmail.com> writes:

It almost seems like they could have tried making a PDP-11 based PC.

>
I dimly remember that there were efforts in that direction.  But the
PDP-11 does not even have the cumbersome support for more than 64KB
that the 8086 has (there were PDP-11s with more, but that was even
more cumbersome to use).
>

 I had thought it apparently used a model similar to the 65C816.
 Namely, that you could address 64K code + 64K data at a time, but then load a value into a special register to access different RAM banks.
 Granted, no first hand experience with PDP-11.
 

DEC also tried their hand in the PC-like business (DEC Rainbow 100).
They did not succeed.  Maybe that's the decisive difference from HP:
They did succeed in the PC market.
>

 I guess they could have also tried competing against the Commodore 64 and Apple II, which were also popular around that era.
 No idea how their pricing compared with the IBM PC's, but in any case, those who had success were generally a lot cheaper.
  Well, except for the Macintosh apparently, which managed to survive with its comparably higher costs.

Yes, but . . .  Its earlier, more expensive incarnation, the Lisa did not survive, which shows there is a limit to how much more people are willing to pay.  And Macintosh was initially successful as a sort of niche machine for "creative types", as opposed to "business users" who used PCs.
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  - Stephen Fuld
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