RFC 674

Procedure Call Protocol Documents, Version 2 🎀

The title block, bestie 📋

• RFC: 674 (NIC 31484) 🦋
• Authors: Jon Postel (JBP) and Jim White, both at SRI-ARC 👯
• Date: 12 December 1974 🌸
• Obsoletes: Version 1 of the PCP documents, plus all the intermediate PCP documents that were informally distributed 💅
• Updates: nothing stated 🙈

The journal header at the top is NLS stuff, so here it is in a code block:

Distribution: /NAG( [ ACTION ] ) NLG( [ ACTION ] ) NSW( [ ACTION ] ) PI( [ ACTION ] )
Sub-Collections: NIC NWG  SRI-ARC NAG NLG NSW PI
RFC# 674
Clerk: JAKE
Origin: < NETINFO, RFC674.NLS;2, >, 11-DEC-74 17:58 JAKE

Hi, it's the NSW crew 💖

okay so, SRI is part of a team building the National Software Works project, and in the middle of all that we came up with a Procedure Call Protocol for the modules that make up the NSW. we genuinely want your thoughts on it, so send them to either of these people:

• James E. White (WHITE@SRI-ARC) or Jon Postel (POSTEL@SRI-ARC)

Augmentation Research Center
Stanford Research Institute
Menlo Park, California 94025

• (415) 326-6200 x2960 (White) or x3718 (Postel) 📞

What's new this release 🔥

this note announces the second published version of several NSW and PCP documents. Version 2 is SUBSTANTIALLY different from Version 1, and it obsoletes Version 1 along with every intermediate PCP document that went around informally. so yeah, the old stuff is retired 💀

Where to find everything 🗂️

every document is on-line in two forms: an NLS file and a formatted text file. the Journal number (like 24459) points to the NLS one, and the pathname (like [SRI-ARC]<NLS>PCP.TXT) points to the text one. you can get the text files over FTP with USER=ANONYMOUS and PASSWORD=GUEST, and no account is needed ✨

Let it be emphasised: anything named like [SRI-ARC]<NLS>name.TXT is an ASCII text file, NOT an NLS file. don't get tricked 🙈

The document lineup 📦

Here's every document, with its journal number, title, what it's about, and where to find it.

• HOST (24581) "NSW Host Protocol" 🖥️
  • This one covers the host-level protocol used in the NSW. It's a slightly constrained version of the standard ARPANET host-to-host protocol, and the constraints touch the allocation, RFNM wait, and retransmission policies.
  • Pathname: [SRI-ARC]<NLS>HOST.TXT
• PCP (24459) "The Procedure Call Protocol" 👑
  • This is the virtual programming environment PCP gives you, plus the inter-process exchanges that make it work.
  • Pathname: [SRI-ARC]<NLS>PCP.TXT
• PIP (24460) "The Procedure Interface Package" 🧚
  • A package that runs in the PCP setting and acts as a procedure-call-level interface to PCP proper. It has procedures for calling, resuming, interrupting, and aborting remote procedures.
  • Pathname: [SRI-ARC]<NLS>PIP.TXT
• PSP (24461) "The PCP Support Package" 🌈
  • Another package in the PCP setting, this one adding to PCP proper, mostly around data store manipulation. It covers getting access to groups of remote procedures and data stores, manipulating remote data stores, and creating temporary ones.
  • Pathname: [SRI-ARC]<NLS>PSP.TXT
• PMP (24462) "The Process Management Package" 🧩
  • The tools for linking two or more processes into a multi-process system (like the NSW). It has procedures for creating, deleting, logically and physically interconnecting processes, and for allocating and releasing processors.
  • Pathname: [SRI-ARC]<NLS>PMP.TXT
• PCPFMT (24576) "PCP Data Structure Formats" 🍓
  • This defines the formats for PCP data structures, each suited to one or more physical channel types.
  • Pathname: [SRI-ARC]<NLS>PCPFMT.TXT
• PCPHST (24577) "PCP ARPANET Inter-Host IPC Implementation" 🔧
  • An implementation of the IPC primitives PCP needs, suited to mediating communication between Tenex forks.
  • Pathname: [SRI-ARC]<NLS>PCPHST.TXT
• PCPFRK (24578) "PCP Tenex Inter-Fork IPC Implementation" 🔧
  • An implementation of the IPC primitives PCP needs, suited to mediating communication between processes on different hosts within the ARPANET.
  • Pathname: [SRI-ARC]<NLS>PCPFRK.TXT
• EXEC (24580) "The Executive Package" 💼
  • A PCP-setting package with procedures and data stores for user identification, accounting, and usage information.
  • Pathname: [SRI-ARC]<NLS>EXEC.TXT
• FILE (24582) "The File Package" 📁
  • Another PCP-setting package. It has procedures and data stores for opening, closing, and listing directories, creating, deleting, and renaming files, and transferring files and file elements between processes.
  • Pathname: [SRI-ARC]<NLS>FILE.TXT
• BATCH (24583) "The Batch Job Package" ⏳
  • A PCP-setting package with procedures for creating and deleting batch jobs, getting the status of a batch job, and talking to the operator of a batch processing host. It's implemented at the host that provides the batch processing facility.
  • Pathname: [SRI-ARC]<NLS>BATCH.TXT
• RJE-MODEL (24655) "The NSW Remote Job Entry Model" 🧠
  • This one walks through using a batch processing facility to finish a programming task in the NSW. The same activity somewhere else might use a remote job entry system.
  • Pathname: [SRI-ARC]<NLS>RJE-MODEL.TXT
• LLDBUG (24579) "The Low-Level Debug Package" 🐛
  • A PCP-setting package with procedures for a remote process to debug, at the assembly-language level, any process it knows about. It can manipulate and search a process's address space and symbol tables, and set and remove breakpoints. Its data stores hold process characteristics, state information, and the contents of program symbol tables.
  • Pathname: [SRI-ARC]<NLS>LLDBUG.TXT
• TBH (24656) "NSW Requirments on Tool Bearing Hosts" 🛠️
  • This covers the environment a tool bearing host needs, and the interfaces to operating system components used by the various PCP packages.
  • Pathname: [SRI-ARC]<NLS>TBH.TXT
• BOXES (24584) "Black Boxes in PCP" ⬛
  • This transliterates the black boxes defined by Millstein and Warshall into the PCP setting, especially the File Package and the Executive Package.
  • Pathname: [SRI-ARC]<NLS>BOXES.TXT

Which doc to read first? 🤔

so HOST is basically a suggestion for some restrictions on the regular ARPANET host protocol for NSW use, and it doesn't affect the rest of the NSW protocols much. you should start with the big PCP documents instead 💖

PCP is where you START. it gives the motivation for the protocol and states the substance of the protocol itself 🫶

then go to PIP, PSP, and PMP. PMP matters most to casual readers, but if you're a programmer coding in the PCP environment, read all three 💅

PCPFMT, PCPHST, and PCPFRK are the low-level communication format specs. they're only for PCP implementers 🔧

EXEC, FILE, and BATCH are procedure packages you implement to provide the accounting/status/usage subsystem, the file subsystem, or the batch processing subsystem. ✨

RJE-MODEL shows how a user would use the NSW tools for tasks they'd otherwise do with a remote job entry system. read it alongside BATCH 🧁

LLDBUG is the debugging package for the PCP environment 🐛

BOXES maps PCP mechanisms onto the File Package procedures and the Black Boxes the Works Manager needs 📦

TBH is about the requirements on the Tool Bearing Host, and how and where the PCP packages hook into an operating system 🛠️