Dublin Core
Title
PDP-9 Core Memory Module (?)
Description
A photo of what is possibly a PDP-9 4K magnetic core memory module / backplane assembly using coincident-current magnetic core memory (see COINC DUAL label)
The top panel shows: DATA ADDRESS Indicators labeled 2048 and 4096
A/B memory sections. The PDP-9 used 4K word memory increments, and systems could be configured with 4K, 8K, 16K, etc. The 2048/4096 labeling corresponds to memory address decoding boundaries within a 4K module.
The indicators marked MODE, WRD, LST, OVFLO, BREAK, .... are status/control signals associated with: Memory cycles, Interrupt/break logic, Overflow detection, etc.
We don't know what the NK04B label represents. The known model numbers of PDP-9 memory units did not have this designation.
The top panel shows: DATA ADDRESS Indicators labeled 2048 and 4096
A/B memory sections. The PDP-9 used 4K word memory increments, and systems could be configured with 4K, 8K, 16K, etc. The 2048/4096 labeling corresponds to memory address decoding boundaries within a 4K module.
The indicators marked MODE, WRD, LST, OVFLO, BREAK, .... are status/control signals associated with: Memory cycles, Interrupt/break logic, Overflow detection, etc.
We don't know what the NK04B label represents. The known model numbers of PDP-9 memory units did not have this designation.
Creator
Digital Equipment Corporation
Date
ca 1967
Contributor
Charles Valentine
Identifier
2026.65