🚀 go-pugleaf

rocker@bucsf.bu.edu (The Long Haired One) writes:

> These are probably a very simple questions. I just don't know the answers.
> I noticed that Pdp11's come in 2 types - qbus and unibus. Do the numbers
> of the machines like pdp-11/23 and pdp-11/24 relate to which is which type?
> 
> And can someone tell me the differences between qbus-ing and unibuses, as
> to which is possibly better or what drawbacks they might hold.

If the last digit is a 3, then it's Qbus.  Anything else indicates a
Unibus machine, ie:

        04,05,10,20,24,30,34,35,40,44,45,50,60,70,84,94 Unibus
        03,23,53,73,83,93                               Qbus

All modern Unibus machines have 4 as their last digit since the /34.
Where there are models with both n3 and n4 numbers, the two usually
have equivalent processors (not sure about the /03 and /04 -- are these
the same chipset?).


Don Stokes, ZL2TNM  /  /                             don@zl2tnm.gp.co.nz (home)
Systems Programmer /GP/ GP PRINT LIMITED  Wellington,       don@gp.co.nz (work)
__________________/  / ----------------   New_Zealand__________________________