RHansen: layout fix

2026-07-22T11:53:00Z

layout fix

← Older revision		Revision as of 11:53, 22 July 2026
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	~~{{Infobox~~		; Model
	~~\|label1=~~Model		: ND-500-II (ND-500/II)
	~~\|data1=~~ND-500-II (ND-500/II)		; Type
	~~\|label2=~~Type		: 32-bit Coprocessor
	~~\|data2=~~32-bit Coprocessor		; Introduced
	~~\|label3=~~Introduced		: 1987 (estimated, with OCTOBUS support)
	~~\|data3=~~1987 (estimated, with OCTOBUS support)		; Processor Architecture
	~~\|label4=~~Processor Architecture		: ND-500 with OCTOBUS line driver
	~~\|data4=~~ND-500 with OCTOBUS line driver		; Key Feature
	~~\|label5=~~Key Feature		: NUCLEUS message passing support
	~~\|data5=~~NUCLEUS message passing support
	}}

	'''ND-500-II''' (also written as '''ND-500/II''' or '''ND-500 Model II''') was a model variant of the [[ND-500]] 32-bit coprocessor that added [[OCTOBUS]] connectivity for integration with [[DOMINO]] I/O controller systems and [[NUCLEUS]] message-passing runtime.<ref name="domino-nucleus"/>		'''ND-500-II''' (also written as '''ND-500/II''' or '''ND-500 Model II''') was a model variant of the [[ND-500]] 32-bit coprocessor that added [[OCTOBUS]] connectivity for integration with [[DOMINO]] I/O controller systems and [[NUCLEUS]] message-passing runtime.<ref name="domino-nucleus"/>

RHansen: Created a reference page for the ND-500-II machine

2026-07-22T11:32:16Z

Created a reference page for the ND-500-II machine

New page

{{Infobox
|label1=Model
|data1=ND-500-II (ND-500/II)
|label2=Type
|data2=32-bit Coprocessor
|label3=Introduced
|data3=1987 (estimated, with OCTOBUS support)
|label4=Processor Architecture
|data4=ND-500 with OCTOBUS line driver
|label5=Key Feature
|data5=NUCLEUS message passing support
}}

'''ND-500-II''' (also written as '''ND-500/II''' or '''ND-500 Model II''') was a model variant of the [[ND-500]] 32-bit coprocessor that added [[OCTOBUS]] connectivity for integration with [[DOMINO]] I/O controller systems and [[NUCLEUS]] message-passing runtime.<ref name="domino-nucleus"/>

The ND-500-II was essentially a classic ND-500 processor that could attach to an OCTOBUS fabric via a special line driver card. This allowed existing ND-500 systems to participate in modern DOMINO and NUCLEUS environments without complete hardware replacement. However, the ND-500-II itself used the traditional [[3022]] + [[5015]] parallel interface (not native OCTOBUS) for CPU communication.

== Contents ==

* [[#Overview|Overview]]
* [[#Architecture|Architecture]]
* [[#Key_Distinction|Key Distinction: CPU vs. System Interface]]
* [[#NUCLEUS_Runtime|NUCLEUS Runtime]]
* [[#DOMINO_Support|DOMINO Support]]
* [[#Hardware_Requirements|Hardware Requirements]]
* [[#Microcode_Versions|Microcode Versions]]
* [[#Historical_Context|Historical Context]]
* [[#Comparison|Comparison Table]]
* [[#References|References]]

== Overview ==

The ND-500-II represented Norsk Data's bridge technology between classic ND-500 systems and modern ND-5000 DOMINO architectures.<ref name="maintenance"/> It maintained backward compatibility with existing ND-500 code while enabling participation in NUCLEUS inter-processor messaging and DOMINO I/O environments.

Key characteristics:
* Retains classic ND-500 CPU architecture ([[3022]]/[[5015]] parallel interface)
* Adds OCTOBUS connectivity via external line driver card
* Supports [[NUCLEUS]] message passing runtime
* Communicates with ND-100 via traditional parallel interface
* Uses [[MPM-5]] (MultiPort Memory) for shared data structures

== Architecture ==

=== CPU Interface ===

The ND-500-II CPU interface is '''not''' OCTOBUS-based. It uses the classic parallel interface:

; [[3022]] Interface (ND-100 side)
: Port and handshake signals

; [[5015]] Interface (ND-500 side)
: Main data and control signals
: Registers: RMAR, RSTA, RCON, MCLR, TERM, TAG

This is identical to pure ND-500 systems. The CPU has no native OCTOBUS support.

=== OCTOBUS Attachment ===

OCTOBUS connectivity for ND-500-II is provided through a dedicated line driver card installed in the ND-100 slot:<ref name="domino-hw"/>

; PCB 3109 (First generation)
: Part number: '''324118'''
: OBCON gate array revision '''36600B'''
: Chip marking: "ND-O2CON TAC 8450" (64-pin package)
: Microcode support: ND-500/2 with revision G or later

; PCB 3096 (Second generation)
: Part number: '''324133'''
: OBCON gate array revision '''36600D'''
: Chip marking: "NDOBCON XAE8740" (smaller square ASIC package)
: Microcode support: ND-500/2 with revision D or later
: Status: Newer ASIC design replacing 3109

The line driver contains:
* OCTOBUS controller gate array (OBCON)
* Differential line transceivers for OCTOBUS signals (XREQ, XCLK, XDAT, XRFO)
* MPM-5 interface logic

=== Shared Memory ===

ND-500-II uses [[MPM-5]] (MultiPort Memory 5) for:
* NUCLEUS kernel data structures
* Port descriptors and message queues
* Synchronization primitives (semaphores)
* Buffer area for messages

The MPM-5 system provides:
* 64KW (128KB) per bank addressing (16-bit registers)
* 256 banks total = 16MW (32MB) maximum
* Multiport access from ND-100, ND-500-II, and controllers

== Key Distinction: CPU Interface vs. System Interface ==

This is the most commonly misunderstood aspect of ND-500-II documentation:

; CPU-to-ND-100 Communication
: Classic parallel [[3022]]/[[5015]] interface (unchanged from ND-500)
: Speed limited by parallel handshake protocol

; ND-500-II in DOMINO System
: Attaches to OCTOBUS fabric via line driver card (PCB 3109/3096)
: Participates in inter-processor messaging via shared MPM memory
: Coordinated via OCTOBUS kicks (short control messages)

The ND-500-II '''CPU itself does not understand OCTOBUS'''. Instead:

# ND-100 I/O processor interfaces to OCTOBUS natively
# NUCLEUS runtime executes in ND-100 (at PIL 12)
# Shared MPM memory carries message structures
# OCTOBUS kicks signal events (process wake-ups, completion notifications)

This delegation through the ND-100 bridges the classic [[3022]]/[[5015]] interface to modern OCTOBUS messaging without changing the ND-500-II CPU.

== NUCLEUS Runtime ==

=== Supported Calls ===

NUCLEUS library functions available on ND-500-II:

; Port Management
: nkCrePort, nkCreName, nkOpenPort, nkOpenReturnPort, nkDelName

; Message Operations
: nkCreMessage, nkMove, nkSend, nkReceive, nkClose

; Information Queries
: nkGetInfo, nkVersion

=== Performance Characteristics ===

Unlike [[ND-5000]] (which microcode-optimizes NUCLEUS for speed), ND-500-II NUCLEUS relies on:

; Time-Critical Functions
: nkMove, nkSend, nkReceive, nkGetInfo
: Executed in ND-100 (via SINTRAN monitor call dispatch)
: NOT microcoded in ND-500-II CPU

; Message Infrastructure
: Stored in shared MPM memory
: Coordinated via OCTOBUS kicks
: Managed by NUCLEUS kernel (ND-100 resident)

Result: ND-500-II NUCLEUS is slower than ND-5000 NUCLEUS but remains suitable for I/O-intensive and soft-real-time workloads where latency is measured in milliseconds, not microseconds.

=== Microcode Execution ===

For ND-5000:
: Time-critical NUCLEUS calls are microcoded in the CPU for sub-microsecond latency

For ND-500-II:
: All NUCLEUS calls dispatch through ND-100 via SINTRAN monitor call interface
: Adds overhead of context switch + ND-100 execution
: Adequate for DOMINO boot/control but not for high-frequency inter-CPU messaging

== DOMINO Support ==

; NUCLEUS Support
: '''YES''' — ND-500-II with OCTOBUS line driver can run NUCLEUS applications<ref name="release-notes"/>

; DOMINO I/O Controller Support
: '''NO''' — DOMINO I/O controllers are exclusive to [[ND-5000]]
: Requires ND-5000 CPU with MFbus and native OCTOBUS support

=== Use Cases ===

ND-500-II with NUCLEUS enables:

* Inter-processor synchronization between ND-500-II and ND-100
* NUCLEUS-based application communication
* Soft real-time message passing
* Control coordination in DOMINO environments (via ND-5000 CPUs)

ND-500-II cannot:

* Host DOMINO I/O controllers
* Provide microsecond-level NUCLEUS latency
* Boot DOMINO controller firmware

== Hardware Requirements ==

To enable OCTOBUS messaging on ND-500-II:

; CPU Subsystem
: * ND-500-II processor (32-bit CPU)
: * ND-100 (or ND-110) I/O processor

; OCTOBUS Connectivity
: * '''PCB 3109''' (part 324118, revision '''G''' or later), ''or''
: * '''PCB 3096''' (part 324133, revision '''D''' or later)

; Memory
: * [[MPM-5]] (MultiPort Memory 5) with minimum capacity
: * Typically 64KW to 256KW per bank for NUCLEUS messaging

; Microcode
: * ND-500/2 microcode version supporting NUCLEUS (see below)<ref name="loader"/>

== Microcode Versions ==

Different ND-500 models required different microcode for NUCLEUS support:

; ND-530
: Microcode '''15312''' (or 15313)

; ND-550 / ND-560 / ND-570
: Microcode '''15212''' (or 15213)
: '''These are the ND-500-II compatible variants'''

; ND-580
: Microcode '''15112''' (or 15113)

The microcode version enables NUCLEUS fast-call execution in the ND-100 CPU at PIL 12.

== Historical Context ==

=== Bridge Technology (1987–1992) ===

ND-500-II represented Norsk Data's strategy for transitioning customers from:

; Legacy Systems (1981–1987)
: Pure ND-500 coprocessors
: Classic [[3022]]/[[5015]] parallel interface
: No inter-CPU messaging or synchronization
: Limited to process-level I/O coordination

; Modern Systems (1988–1995)
: ND-5000 with DOMINO I/O
: Native OCTOBUS architecture
: NUCLEUS inter-processor messaging
: Microsecond-latency real-time I/O

ND-500-II allowed organizations to:

* '''Preserve existing investment''' in ND-500 systems
* '''Add NUCLEUS messaging''' without CPU replacement
* '''Integrate with DOMINO''' environments (via shared NUCLEUS)
* '''Migrate gradually''' from parallel to serial interfaces
* '''Avoid forklift upgrades''' to pure ND-5000

=== Timeline ===

; 1981
: ND-500 introduced ([[3022]]/[[5015]] parallel interface only)

; 1987
: ND-500-II upgrade path defined with OCTOBUS line driver
: NUCLEUS runtime released for ND-5000 and ND-500-II

; 1988
: ND-5000 native OCTOBUS and DOMINO released
: ND-500-II becomes "bridge" to DOMINO

; 1992–1995
: ND-500-II systems gradually phased out as ND-5000 became primary platform

== Comparison ==

{| class="wikitable" style="text-align: center"
|-
! Characteristic
! ND-500
! ND-500-II
! ND-5000
|-
| '''CPU Architecture'''
| 32-bit ND-500
| 32-bit ND-500
| 32-bit ND-5000 (pipelined)
|-
| '''CPU Interface to ND-100'''
| [[3022]]/[[5015]] parallel
| [[3022]]/[[5015]] parallel
| Octobus native
|-
| '''Octobus Capable'''
| No
| Yes (via PCB 3109/3096)
| Yes (native)
|-
| '''NUCLEUS Support'''
| No
| Yes
| Yes
|-
| '''DOMINO Support'''
| No
| No
| Yes
|-
| '''Shared Memory Type'''
| [[MPM-5]] only
| [[MPM-5]] + Octobus
| [[MFbus]] + Octobus
|-
| '''NUCLEUS Fast Calls'''
| N/A
| ND-100 execution (PIL 12)
| Microcoded in CPU
|-
| '''Message Latency'''
| N/A
| Milliseconds
| Microseconds
|-
| '''Primary Use Case'''
| Standalone ND-500
| NUCLEUS messaging + soft real-time I/O
| DOMINO I/O + high-speed messaging
|}

== See Also ==

* [[ND-500]] — The base architecture
* [[ND-5000]] — The modern successor
* [[NUCLEUS]] — Message-passing runtime
* [[DOMINO]] — I/O controller system
* [[OCTOBUS]] — The serial signaling bus
* [[MPM-5]] — Multiport memory system

== Product Numbers ==

* Model designation: '''ND-500/II'''
* Octobus Line Driver: '''324118''' (PCB 3109, earlier) or '''324133''' (PCB 3096, later)

== References ==

<references>
<ref name="domino-nucleus">Norsk Data Document '''ND–820026.1''' ''DOMINO and NUCLEUS Software Guide'', preface and NUCLEUS Overview sections</ref>
<ref name="maintenance">Norsk Data Document '''ND–05.017.01 EN''' ''ND-5000 HARDWARE MAINTENANCE'', chapter 3 (CPU type selection: "ND-500/I (0), ND-5000 (S) or ND-500/IIO (G)")</ref>
<ref name="domino-hw">Norsk Data Document '''ND–14001-1-EN''' ''DOMINO Standard Hardware Description'', page 123 ("The cable is used to connect MFbus banks, ND-100 and ND-500 model II to the OCTObus")</ref>
<ref name="release-notes">Norsk Data Document '''ND–860230-8-EN''' ''SINTRAN III - Release Information - N-version'', NUCLEUS requirements section</ref>
<ref name="loader">Norsk Data Document '''ND–60.136.04A''' ''ND-500 Loader/Monitor''</ref>
</references>

== External Links ==

* [[Documentation list-Mixed_hardware_software#ND-20.026_DOMINO_and_NUCLEUS_Software_Guide|ND-820026.1 DOMINO and NUCLEUS Software Guide]]

[[Category:ND-500 Series]]
[[Category:Octobus Systems]]
[[Category:NUCLEUS]]
[[Category:32-bit Computers]]

ND-500-II - Revision history

RHansen: layout fix

RHansen: Created a reference page for the ND-500-II machine