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PDP 11/60 versus PDP 11/84 retoration.

Hi All;
It makes me wonder what other projects got cancelled by them..
They cancelled the PDP-X, and this for the PDP 11/74, it would be interesting to find out what else they started and somewhere in the middle of it, they axed it..
"" and the third was a microsequencer/control store. The microcode store for the CIS was 96 bits wide by 4096 words deep. "" That had to be some Micro-sequencer..
THANK YOU Marty
Well, I know they cancelled the Jupiter project which was the follow on to the existing pdp-10 line. I believe the Vax had a lot to do with that happening.
I am sure the details are available in other forums.
 
The user writable microprogram control store is possibly the reason this particular one was purchased for its particular use. Although there is no WCS card in this box, it could have been something that was being looked at; the system software itself was written in FORTH, and the WCS fits the FORTH paradigm perfectly.

Not being FORTH-competent this conclusion is not obvious to me; why do you think this? Stack-orientation is the most obvious characteristic of FORTH. I don't see how a WCS would benefit this.

I can see implementing a FORTH "kernel/ISP" using the WCS (akin to the PDP-8 ISP that Don mentioned earlier). Whether that would be particularly efficient, compared to an implementation using the native PDP-11 ISP, isn't clear. Perhaps Don could comment based on his experience?

BTW, notice that this installation appears to be based on the OEM-flavor of the 11/60 that DEC sold. A "basic" chassis, a console, and your elbow grease :->.
 
Not being FORTH-competent this conclusion is not obvious to me; why do you think this? Stack-orientation is the most obvious characteristic of FORTH. I don't see how a WCS would benefit this.

Sun's OpenFirmware/OpenBoot is the classic example of the FORTH language extension paradigm; write a procedure and it can very easily become part of the interactive interpreter's language vocabulary. Extending that paradigm down to the microcode level is one potential use for the WCS and variants. So you'd add custom instructions in the WCS that would extend the machine code in much the same way as you extend FORTH with your own procedures.
I can see implementing a FORTH "kernel/ISP" using the WCS (akin to the PDP-8 ISP that Don mentioned earlier). Whether that would be particularly efficient, compared to an implementation using the native PDP-11 ISP, isn't clear. Perhaps Don could comment based on his experience?

BTW, notice that this installation appears to be based on the OEM-flavor of the 11/60 that DEC sold. A "basic" chassis, a console, and your elbow grease :->.

Ah, thanks for that info. I wasn't aware such a beast existed.
 
Hi All;
M-Thompson, "" You really haven't lived until you heard the Open Firmware theme song sung to the tune of the Flintstones by Mitch Bradley. ""
Would it be too much to ask, where can this be Found ??

THANK YOU Marty
 
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