SPROGS Technical Paper No 16: Documentation on RSX PLUS III

J R Gallop

31 January 1974

CURRENTLY AVAILABLE DOCUMENTATION

The system RSX PLUS III that has been received from DEC is a pre-release version and the documentation unfortunately rather reflects this. It consists of the DOS user's manual, the "RSX PLUS Real Time Executive Reference Manual' and a loose leaf set of specifications on the differences between RSX PLUS III and RSX PLUS.

I have two spare copies of the RSX PLUS manual if anyone wants a personal copy and does not have one. One copy will be kept by the PDP15 in any case. The bulk of this manual remains unaffected by the introduction of RSX PLUS III.

The set of RSX PLUS III specifications will be kept near the PDP15. In order to make it easier to use, the pages have been numbered and a list of contents is attached to this paper.

The fundamental changes in RSX PLUS III which can be said to generate the changes outlined in the RSX PLUS III Specifications are:

(a) DOS is amalgamated with RSX which means a change to the way in which the RSX disc handlers (RF and DK) arrange the disc.

(b) RSX PLUS III supports all 3 kinds of disc (RF the fixed head disc that ACL has, RP the exchangeable disc cartridge, and RK, the disc made available in the unichannel) compared with RSX PLUS which just supports RF. The effect is that certain commands and routines that use the disc require the type of disc to be stated in the argument list.

(c) RSX PLUS III allows the user to reconfigure the system and there are MCR commands in the specifications to perform arrangement of partitions RCP, reassignment of task-to-partition ASP, adding of a new device to the system ADV.

(d) Some of the design Bugs in RSX PLUS are tinkered with in RSX PLUS III. For instance, in RSX PLUS a user must SAV his core-image after INStalling or REMoving a task from the system, otherwise either the system crashes or disc blocks are lost for ever. RSX PLUS III cures the REMove problem but not the INStall problem. Another paper is being produced which outlines the problem that may be experienced in using RSX and require reprogramming.

TITLES OF RSX PLUS III SPECIFICATIONS

#302 Event variable settings.

These are altered. This new list completely replaces Appendix A in the RSX PLUS manual.

#303 'ADV' MCR function

New MCR command which allows user to add a device name to the system.

#304 'ASP' MCR function

New MCR command which allows an installed task to belong to a different partition.

#305 Change to the 'OPEN' MCR function

Different typing format when printing out a disc block.

#306 Change to the 'TASKS' MCR function

#307 Changes and additions to the disc and magnetic tape FORTRAN subroutines

This refers to the disc routines in section 5.6 of the RSX PLUS manual. It is now necessary to state what sort of disc is being used. Ours is RF. There is a new routine UPKEV to unpack handler information. The parameters in the FORTRAN callable magnetic tape routines RDCOMP, MTGET and MTPUT are altered - refer sections 5.8.1, 5.8.12 and 5.8.13 of the RSX manual.

#308 Changes to the 'DIRECTORY' (or 'DIR')

TDV task (section 6.5.8 in RSX PLUS manual) (1) Different command format. Type of disc is now required. In other words, at ACL DIR RF must now be typed instead of just DIR (2) New error messages (3) New LUN slot. 16 is used for the directory listing.

#309 'MNT' and 'DSM' MCR functions

Only apply to disc cartridge systems

#310 List of RSX PLUS III system directives

This is a list of all the CAL'S 23 in the RSX PLUS III system (QUEUE I/0 includes all the I/O requests). It completely replaces section 4.5 of the RSX PLUS manual. SPY, SPYSET and QJ0B are new.

#311 List of SCOM registers in RSX PLUS III

These are the system registers in Executive. Completely replaces appendix F of the RSX PLUS manual.

#312 Disk I/0 driver task

This description replaces section 11,12 of the RSX PLUS manual. The main change is to support other sorts of disc, a facility which is superfluous for us.

#313 Disk file handler tasks

This description replaces section 11,13 of the RSX PLUS manual. The main change is how DOS and RSX are reconciled. This is important for anyone programming the disc. The DEFINE subroutine is altered.

#314 FORTRAN changes under RSX PLUS III

Certain FORTRAN callable subroutines described in the RSX plus manual are changed in specification. There is a new compiler option H which determines whether in-line code is used to generate array addresses.

#315 (120-100-317-100), (120-100-317-100

Changes to the random access I/0 routines in FORTRAN - DEFINE, READ, WRITE. Initial system configuration under RSX PLUS III.

#316 RCF and RCP MCR functions

These are the commands that reconfigure RSX 87 New while it is running. Partitions and common blocks can be added, modified or deleted, Node partitions can only be added. RCP just adds partitions.

#317 SAVE/REMOVE/INSTALL problem

RSX plus caused problems if the SAVE command 95 (save a core image on disc) was not used at the right time. This section describes a partial solution to SAVE/REMOVE in RSX PLUS III. There still remains a problem with SAVE/INSTALL. Basically the rule is use SAVE immediately after INSTALL or REMOVE so that the information blocks on disc and in store are compatible.

#318 RSX PLUS III Checkout package

#320 'DEQ' MCR function

Prints out the contents of the system lists.

#323 FORTRAN subroutines SPY, SPYREL, SPYSET, QJOB

New system routines which can SPY on locations in Executive and add batch jobs to a queue.