Editing PDP-10 (section)

===KA10===
The KA10 has a maximum main memory capacity (both virtual and physical) of 256 [[kiloword]]s (equivalent to 1152 [[kilobyte]]s); the minimum main memory required is 16 kilowords. As supplied by DEC, it did not include [[paging]] hardware; [[memory management]] consists of two sets of protection and relocation registers, called ''[[base and bounds]]'' registers. This allows each half of a user's [[address space]] to be limited to a set section of [[main memory]], designated by the base physical address and size. This allows the model of separate read-only shareable code segment (normally the high segment) and [[read-write]] data/[[Stack (data structure)|stack]] segment (normally the low segment) used by [[TOPS-10]]  and later adopted by [[Unix]]. Some KA10 machines, first at MIT, and later at [[BBN Technologies|Bolt, Beranek and Newman]] (BBN), were modified to add [[virtual memory]]<ref>{{cite web |url=http://bitsavers.org/pdf/bbn/pager/Technical_Details_of_the_BBN_Pager_Model_701_197007.pdf |title=Technical Details of the BBN Pager Model 701 |first1=Theodore R. |last1=Strollo |first2=Jerry D. |last2=Burchflel |first3=Raymond S. |last3=Tomlinson |author3-link=Ray Tomlinson |date=July 22, 1970 |publisher=[[BBN Technologies|Bolt, Beranek and Newman]]}}</ref><ref>{{cite web |title=A Virtual Memory System for the PDP-10 KA10 Processor
|url=https://apps.dtic.mil/sti/citations/ADA028987
|last=McNamee |first=L. P. |date=1976}}</ref> and support for [[demand paging]],<ref>{{cite journal |title=TENEX, a Paged Time Sharing System for the PDP-10
|journal=[[Communications of the ACM]]
|volume=15|issue=3
|url=https://cseweb.ucsd.edu//classes/wi19/cse221-b/papers/bobrow72.pdf
|citeseerx=10.1.1.509.1454
|last1=Bobrow |first1=Daniel G. |author1-link=Daniel Bobrow
|last2=Burchfiel |first2=Jerry D.
|last3=Murphy |first3=Daniel L. |author3-link=Daniel Murphy (computer scientist)
|last4=Tomlinson |first4=Raymond S. |author4-link=Ray Tomlinson
|date=March 1972 
|pages=135–143
|doi=10.1145/361268.361271
|s2cid=52848167
|quote=PDP-10 processor augmented by special paging hardware}}</ref><ref>{{cite web |date=June 1, 1982
|title=DECsystem-10/DECSYSTEM-20 Processor Reference Manual
|url=http://pdp10.nocrew.org/docs/ad-h391a-t1.pdf
|quote=DECsystem-10 ... dynamic paging and working set management}}</ref> and more physical memory.

The KA10 weighs about {{convert|1920|lb|kg}}.<ref>{{cite book |title=PDP-10 Installation Manual |url=http://www.bitsavers.org/pdf/dec/pdp10/KA10/PDP-10_InstallationMan.pdf |page=5 |publisher=Digital Equipment Corporation}}</ref>

The 10/50 was the top-of-the-line Uni-processor KA machine<ref name=JSYS104>{{cite web
|url=http://tenex.opost.com/hbook.html |title=Origins and Development of TOPS-20
|last=Murphy |first=Dan |date=1989}}</ref> at the time when the ''PA1050'' software package was introduced. Two other KA10 models were the uniprocessor 10/40, and the dual-processor 10/55.<ref>{{cite web 
|title=PDP-10 models |date=June 30, 2001 |url=http://www.inwap.com/pdp10/models.txt
|quote=PDP 1055 Dual processor (1050) system ...  early DEC-10 monitors}}</ref>{{efn|also marketed as 1040, 1050, 1055, as per the KI/KL models as 1060, 1070, etc.}}