[rescue] huge DEC rescue in TX?
Jonathan C. Patschke
jp at celestrion.net
Thu Feb 3 15:52:12 CST 2005
On Thu, 3 Feb 2005, Wai-Sun Chia wrote:
>> That's funny. There are quite a lot of socketed chips on mine.
> I was refering to the CPU: i.e. there's no socketed CPUs like the
> PGA (socket 7), etc.
Well, again, it depends on the model. The CPUs in the 11/23, 11/73, and
11/53 are socketed. They're large DIPs, though, instead of PGAs.
> Yeah. The wierd thing is that even though a wire-wrapped backplane *LOOKS*
> flimsy, it is quite robust indeed. The fact that they're still working after
> 25-30 years is a testament of the engineering quality that goes into a
> typical PDP.
Very true. It's a shame that it's so impractical (to the point of being
impossible) at higher clock rates. You really can't hack on modern
machines like you can on older stuff like that. I mean, I'm going to
extend my 11/23's bus from 18-bits to 22-bits sometime in the future.
That's a very foreign concept in the microcomputer world.
>> I think the "CPU" is just a single 40-pin DIP. The others are the MMU
>> and additional microcoded instructions. Everything about that platform
> Well, to me a MMU and microcode are *part* of the CPU. :-)
Well, that's up for debate. Microcode maybe, but not necessarily the
Jonathan Patschke ) "Let me hear you make decisions
Elgin, TX ( without your television."
USA ) --Depeche Mode, "Stripped"
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