R7 (program counter)
E697037
R7 (program counter) is the PDP-11 CPU register that automatically tracks the address of the next instruction to be executed, effectively serving as the machine’s program counter.
All labels observed (1)
| Label | Occurrences |
|---|---|
| R7 (program counter) canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T7920726 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: R7 (program counter) Context triple: [PDP-11, hasRegister, R7 (program counter)]
-
A.
R70
R70 is a London bus route that provides public transport connections to and from Hampton and surrounding areas.
-
B.
R37
R37 is a regional road in South Africa that serves as a key route connecting the town of Lydenburg with other parts of the Mpumalanga and Limpopo provinces.
-
C.
R-4
The R-4 is a World War II–era Sikorsky helicopter recognized as the first mass-produced helicopter and the first to be used operationally by the U.S. military.
-
D.
RAS
RAS is the commonly used abbreviation for the Royal Astronomical Society, a leading learned society dedicated to the advancement of astronomy and geophysics.
-
E.
R-17
R-17 is the Soviet-designed short-range ballistic missile better known in the West by its NATO reporting name "Scud-B."
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: R7 (program counter) Target entity description: R7 (program counter) is the PDP-11 CPU register that automatically tracks the address of the next instruction to be executed, effectively serving as the machine’s program counter.
-
A.
R70
R70 is a London bus route that provides public transport connections to and from Hampton and surrounding areas.
-
B.
R37
R37 is a regional road in South Africa that serves as a key route connecting the town of Lydenburg with other parts of the Mpumalanga and Limpopo provinces.
-
C.
R-4
The R-4 is a World War II–era Sikorsky helicopter recognized as the first mass-produced helicopter and the first to be used operationally by the U.S. military.
-
D.
RAS
RAS is the commonly used abbreviation for the Royal Astronomical Society, a leading learned society dedicated to the advancement of astronomy and geophysics.
-
E.
R-17
R-17 is the Soviet-designed short-range ballistic missile better known in the West by its NATO reporting name "Scud-B."
- F. None of above. chosen
Statements (35)
| Predicate | Object |
|---|---|
| instanceOf |
CPU register
ⓘ
program counter ⓘ |
| addressingModeRole |
serves as base for PC-relative addressing
ⓘ
supports immediate addressing via PC-relative modes ⓘ |
| addressSpace |
PDP-11 memory address space
ⓘ
linked to:
PDP-11
|
| alsoKnownAs |
PC
ⓘ
program counter ⓘ |
| architecture | PDP-11 ⓘ |
| autoIncrements | on instruction fetch ⓘ |
| belongsToFamily |
DEC PDP-11
ⓘ
linked to:
PDP-11
|
| canBeModifiedBy |
branch instructions
ⓘ
jump instructions ⓘ return instructions ⓘ subroutine call instructions ⓘ |
| category | computer architecture concept ⓘ |
| dataType | memory address ⓘ |
| function | holds the address of the next instruction to be executed ⓘ |
| influences | execution flow of PDP-11 programs ⓘ |
| introducedIn | early 1970s ⓘ |
| isGeneralPurposeIn | PDP-11 programmer’s model of 8 registers ⓘ |
| manufacturer | Digital Equipment Corporation ⓘ |
| partOf |
PDP-11 CPU
ⓘ
linked to:
PDP-11
PDP-11 register set ⓘ
linked to:
PDP-11
|
| readableBy | PDP-11 software via register access ⓘ |
| registerNumber | 7 ⓘ |
| resetBehavior | loaded with start address on reset or boot ⓘ |
| specialRole | dedicated to program counter function ⓘ |
| tracks | address of the next instruction ⓘ |
| updatedOn | every instruction fetch ⓘ |
| usedBy | PDP-11 instruction decoder ⓘ |
| usedFor |
control flow
ⓘ
instruction sequencing ⓘ |
| usedIn | instruction fetch stage ⓘ |
| width | 16 bits ⓘ |
| writableBy | PDP-11 software via control-flow instructions ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: R7 (program counter) Description of subject: R7 (program counter) is the PDP-11 CPU register that automatically tracks the address of the next instruction to be executed, effectively serving as the machine’s program counter.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject linked to:
R3