FIELD SERVICE SOFTWARE ASSISTANCE BROCHURE
D E C X 8
Prepared by:
Rick Moore
INTRODUCTION
This document concerns the building, initializing, and running
of a customized version of the PDP-8 System Exerciser, DECX8.
The following procedure assumes that the user has a working
knowledge of rudimentry OS-8 techniques such as booting the system,
listing directories, and saving programs. It is also assumed that the
neccessary DECX8 builder and execisor modules are available on an OS-8
media, specifically a disk (RK05 or RL01), a Diskette, or a DECtape.
For more detailed information, please reference :
AC-C276E-MA - AXQABE0 DEC/X8 User's Guide
and appropriate module listings in the microfiche library.
DECX8 System Concepts
DECX8 is a modular software system in that the total system may
have many unique software configurations dependent upon the type and
placement of various software modules. Software exerciser modules may
be inserted into a predetermined skeletal frame and initialized with
the particular parameters to give the tailored exerciser the desired
characteristics. In this manner, DECX8 can be "tuned" to exercise the
hardware with much the same loading factor as the operating system
software.
DECX8 may be built for any size system; from 8K to 32K, or even
up to 128K if the KT8A Memory Management Option is available. For
purposes of general discussion, we will assume a system size of 16K.
A DECX8 software module (job) is a sub program designed to
exercise specific hardware functions under control of the DECX8
software system. There are two basic types of software modules,
interrupt driven and background. Interrupt driven modules exercise
devices which cause program interrupts. The continued running of this
type of module is dependent on its next device interrupt. Background
modules are self sustaining programs and do not generate or require
program interrupts.
The sequence in which jobs are serviced, both for interrupts
and housekeeping, is a function of each job's priority. Under normal
operating conditions, the higher priority jobs are serviced first. Job
priorities are assigned by the user at build time and remain fixed
thereafter. The designation for job priority is a two digit octal
number starting at the highest priority , 00, to the lowest, 37. In
addition, if the system has greater than 32K words of memory and a
KT8A Memory Management option, it will be neccessary to map the
priority of the Data Break options.
Each software job, running at a given priority, is located in a
"jobslot", of which there are 4 per memory field. The first 2 are 4
page slots, the remaining 2 are 2 page slots. An exercisor module that
takes 2 pages may reside in a 4 page slot, but not visa-versa.
Therefore our system of 16K looks like:
SLOT MEMORY FIELD
0 1 2 3
-----------------------------------
| | | | |
1 | 4 page | 4 page | 4 page | 4 page |
| | | | |
-----------------------------------
| | | | |
2 | 4 page | 4 page | 4 page | 4 page |
| | | | |
-----------------------------------
| | | | |
3 | 2 page | 2 page | 2 page | 2 page |
| | | | |
-----------------------------------
| | | | |
4 | 2 page | 2 page | 2 page | 2 page |
| | | | |
-----------------------------------
BUILDING PHASE
The OS-8 medium that DECX8 is contained on must be initialized
by normal methods. Then type:
".R DECX8" ( or whatever it is called )
If you are running from the NED Diagnostic System, the program
will come up running, if not, it will halt at location 201.
a) place the device code of the console teleprinter
(usually 04) in SR bits 3-8 and hit continue. The TTY
will print a message and halt again.
b) place the device code of the console keyboard
(usually 03) in SR bits 3-8 and hit continue.
the program will now print:
HSR? - if there is a high speed reader, answer "Y";
if not, "N"
DEVICE CODE - if "Y" to above; enter device code of reader
( usually 01 )
HSP? - answer "Y" or "N" for high speed punch
DEVICE CODE - same as above ( usually 02 )
EXT MEM? - type the number of the highest memory field
in the system (00-37)
the program will now determine the type of CPU:
PDP-8? - "Y" only if the processor is a traditional 8
PDP-8/E? - "Y" for an 8/e; "N" otherwise
VT78? - "Y" for a VT78; if "N" to all the above, a
8L/8I is assumed
NOTE:
The purpose of the VT78 question is to remove any halts or
references to the SR from the customized version of the exerciser
being built since a VT78 has no hardware switch register. However, the
"Catch-22" of this is that without a switch register, it is impossible
to enter the 03-04 device codes and hit continue. The program
"DECX8.SV" on the NED Diagnostic System has patches (listed at the end
of this text) which remove these halts and assume a console device
code of 03-04 so it is possible to build DECX8 on a VT78 or PDP-8A
with no switch register.
the program will now determine which options exist:
(answer "Y" or "N" for each query)
KT? * - for KT8A Memory Management option
VT100? - inserts XON / XOFF capabilities for slow
scroll operation over 2400 baud
EAE? - Extended Arithmetic Element
PF? - Power Fail / Auto Restart option
MP? - Memory Parity option
TS? - Time Sharing Control is active
* if you specify a KT8A, it will be neccessary to map the
priority of any Data Break devices during the initalization
stage. See the section on initialization for more information.
NOTE: For the remainder of this document, the operator to computer
responses will be enclosed in [] brackets, while program to
operator prompts are in plain text.
At this time, the program will print:
^C
! and you are in the DECX8 monitor
To transfer control to the builder
! [^B] OK? [Y]
The program will ask:
INPUT VIA OS/8? [Y]
OUTPUT VIA OS/8 USING FILE BASED DEVICE? [Y]
% [B] this prompt indicates the program is ready to
accept builder commands and then prints
PRI:00 % indicating the program is waiting for the
jobslot assignment for priority level "00"
At this time, install the various jobs into the system as the
jobslots are opened. You may be asked to provide information
concerning device codes, word count, and current addresses. In most
cases, the default values may be taken by typing a <CR> but any
nonstandard values can be specified.
Install them in priority order, with the fast data break
devices first, followed by interupt driven devices, and then the
background programmed I/O devices. This is a general rule to which
some noteworthy exceptions are that "TIMERA" must be PRI00 if it is
installed; "TC01DT" must be highest priority (after TIMERA). These and
other special conditions are noted in the individual module writeups
that are included in the DECX8 section of the Microfiche Library.
After all of the jobslots are filled:
PRI:nn % [^C] CTRL C to return to DECX8 monitor
! [S] to list all the modules you have inserted
At this time, you must initalize some of the modules with
various parameters to tell the system, for example, the number of disk
drives to be run, the data patterns to be run, etc.
! [IJfx] where "fx" is the jobslot (ie: IJ01, IJ13)
or ! [AI] Initialize all jobs
The initialization data for each module is listed in the
various modules writeups in the Microfiche Library.
If you have built a system that includes a KT8-A Memory
Management option (more than 32K words od memory), it is neccessary to
map the priority of the Data Break devices. This situation usually
arises on the new 211 Series Word Processors. If this is not done,
these devices will report numerous data errors and appear to be
faulty.
![MPJfx] followed by the assigned priority for the
device
Examples of such devices are RL01s and RK05s.
When all jobs are initialized:
! [^B] ^B OK? [Y]
% [P] this will write the newly created exercisor to
the OS/8 media. Give it any name you wish, but
for consistency, please use the extension ".X8"
At this time, the customized version of DECX8 is saved on the
OS/8 media, and can be run by typing:
.R MYPROG.X8
! [AR] run all jobs
! [^E] begin exercising
The following text is typical of the dialogue to build, save,
and run a customized version of DECX8. Our target system will be a
PDP-8A with 16K of memory,2 RK05 drives, a TC08 DECtape controller
with a dual drive TU56,2 RX01 dual floppies, a KL8A (M8319) Multiple
SLU option connected to two terminals at 9600 baud, and an LP05
printer. The terminal is a VT100 connected to the M8316 module.
A map of our jobslot layout could look like:
SLOT MEMORY FIELD
0 1 2 3
-----------------------------------
| | | | |
1 | TIMERA | RANMRI | MULSLU | FLOPPY | 4 page jobs
| | | | (2&3) |
-----------------------------------
| | | | |
2 | FLOPPY | TC01DT | RK8EDS | OPRATE | 4 page jobs
| (0&1) | | | |
-----------------------------------
| | | | |
3 | MRI08A | PRNTER | OPRATE | MRI08A | 2 page jobs
| | | | |
-----------------------------------
| | | | |
4 | NOTFUN | OPRATE | MRI08A | OPRATE | 2 page jobs
| | | | |
-----------------------------------
OF SPECIAL NOTE:
- TIMERA must be J01
- there are two FLOPPY modules that will be given different
device codes
- a 2 page job (OPRATE) can live in a 4 page slot
- any unused slots are filled with background jobs (OPRATE and
MRI08A)
- when building for a VT78 system, there may be patches to the
modules that must be made. Consult the module writeups for
particulars.
- if a KT8A is present, the priority of the Data Break devices
must be mapped with the [MPJfx] command.
BUILDING DIALOGUE
note: operator responses are enclosed in brackets []
.R DECX8 - the OS/8 media is booted and the
DECX8 monitor/builder is called and
identifies itself
HSR? [N]
HSP? [N] - the system has no PC04
EXT MEMORY (00-37) [03] - we have fields 00-03 (16K)
PDP-8? [N] - not a "Straight-8"
PDP-8E [Y] - same as an 8A !
KT? [N]
VT100? [Y] - as our console terminal
EAE? [N]
PF? [Y] - comes "free" on the M8317 in the 8A
MP? [N]
TS? [N]
^C
! [^B] ^B OK? [Y] - now in builder mode
INPUT VIA OS/8? [Y]
OUTPUT VIA OS/8 FILE BASED DEVICE? [Y]
% [B] - begin to build, installing modules in
priority order
PRI:00% [J01]
*TIMERA
DC = 0130 - type a carraige return to take the
default device code of 13 for the
clock (remember there is one on the
M8316 in the 8A!)
PRI:01% [J12]
*TC01DT - remember the TC08 must be first after
DC = 0760 the clock module
= 0770
WC = 7754 take all the default values for word
count
CA = 7755
PRI:02% [J22]
*RK8EDS - the RK05 controller module
DC = 0740
PRI:03% [J13]
*PRNTER - now do the fastest interupt driven
DC = 0660 jobs such as the line printer
PRI:04% [J21]
*MULSLU - the KL8A is next
DC = 0400
0410 - 40 & 41 are the standard device codes
for the four line M8319
PRI:05% [J02] - now the programmed I/O devices
*FLOPPY
DC = 0750 drives 0 & 1 have the standard device
code of 75
PRI:06% [J31]
*FLOPPY - but drives 2 & 3 have their own
DC = 0750 [0700] control board that we have set for
device code 70 (note that this could
be other address we set the hardware
to). Be aware that the normal code
for the 2nd. set of floppies is 76
but since this system has DECtapes at
that code, we choose 70.
PRI:07% [J11] - now install the background jobs
*RANMRI
PRI:10% [J34]
*OPRATE
PRI:11% [J03]
*MRI08A
PRI:12% [J04]
*NOTFUN
PRI:13% [J32]
*OPRATE
PRI:14% [J33]
*MRI08A
PRI:15% [J24]
*MRI08A
PRI:16% [J23]
*OPRATE
PRI:17% [J14]
*OPRATE
PRI:20% [^C] - no more jobslots available; return to
builder monitor
! - now you have to initialize the
exercisor
! [IJ01]
TIMERA
A [232] - remember that these parameters are
B [0001] for the M8316 module
C [0144]
D [0]
! [IJ02]
FLOPPY
A [0]
B [0]
C [0]
D [0]
! [IJ03]
MRI08A
! [IJ04]
NOTFUN [0]
01 [03] - now you must insert ALL of the valid
02 [04] device codes starting with the TTY
03 [10] - power fail IOTs are on the M8317
04 [13] - clock
05 [20] - have to list
06 [21] all of the
07 [22] extended
10 [23] memory
11 [24] IOTs on the
12 [25] M8317 module (20-27)
13 [26]
14 [27]
15 [40] - 40 & 41 are for the M8319 Multiple
16 [41] Serial Line Interface
17 [57] - this is the M8316 Parrallel Port
20 [66] - line printer
21 [70] - floppy drives 2 & 3
22 [74] - RK8E
23 [75] - floppy drives 0 & 1
24 [76] - 76 & 77 are the TC08 DECtape
25 [77]
26 [00] - 00 is the CPU IOTs and the end of the
table
*** note: if you are initializing this module for a VT78,
be sure to include [07] which is the VT78 panel
memory IOT. For a PDP-8A with a M8316 module,
[57] is the parallel port. These must be
included or NOTFUN will give errors.
!IJ11
RANMRI
!IJ12
TC01DT
A [0]
B [1] - lowest & highest drive numbers
C [1] [0004] - start with block 4
D [0]
E [0]
F [0]
!IJ13
PRNTER
A [0100] - # of characters
B [0204] - 132 columns (80 column would be 0120)
C [0]
D [0]
E [0]
F [0]
!IJ14
OPRATE [2] - this is an 8/e or 8/a
!IJ21
MULSLU [1] - indicates we are going to terminals
0 [2] [377] line 0 to terminal, full ASCII
1 [2] [377] character set to be transmitted
2 [0]
3 [0] lines 2 and 3 are deactivated
!IJ22
RK8EDS
A [0] - lowest drive # 0
B [1] - highest is #1
C [0]
D [0]
E [0]
!IJ23
OPRATE [2]
!IJ24
MRI08A
!IJ31
FLOPPY
A [0]
B [0]
C [0]
D [0]
!IJ32
OPRATE [2]
!IJ33
MRI08A
!IJ34
OPRATE [2]
! [^B] ^B OK? [Y] - now to save the exercisor on your
disk
% [P]
UPON ".", TYPE "SAVE (DEV) (FILE)" - - -
. [SAVE SYS TEST.X8]
. - you are back in OS-8 monitor and
done!
DECX8 Runtime Switch Register Options
SR Bit State Function
______ _____ ________
0 0 Monitor serves jobs according to priority
1 Monitor serves jobs in a sequential manner
1 0 All jobs run in "Executive" mode only
1 All jobs run in "User" mode whenever possible
2 0 Enable normal Rotate and Status reports
1 Disable normal reports and ignore ^S requests
3 0 Status reports generated in long form
1 Status reports generated in short form
4 0 Enable slot rotation if memory larger than 8K
1 Disable slot rotation
* 5 0 Jobs MQ contents are preserved and restored
1 MQ displays priority of current job
6 0 Errors take normal exit to failing job
1 Non-fatal errors return to keyboard monitor
7-8 00 Report all errors including all bad data
01 Report errors and first 4 sets of bad data
10 Report all errors except data errors
11 Report no errors
9 0 Upon error the job continues to run
1 Upon error the kill flag for the job is set
10 0 Random external buffer usage occurs
1 Present external buffer assignments frozen
11 0 Random device, unit, and address selection
1 Device, unit, and address selection frozen
* DO NOT set to a 1 if any EAE jobs are running!
DECX8 Keyboard Command Summary
Command Function
_______ ________
^B Switch control to Builder
^C Calls DECX8 Keyboard Monitor
^E Exercise all Enabled Jobs
^R Force Rotation and Exercise jobs
IJfx Initialize Job "Jfx"
MPJfx Map Priority for device in Job "Jfx"
RJfx Run Job "Jfx"
KJfx Kill Job "Jfx"
AI Initialize All Jobs
AK Kill All Jobs
AR Run All Jobs
^OBfaaaa Modify Field "f" Location "aaaa"
^OJfx Relative mode memory modification
RRRR Relative address in "Jfx"
S Generate Status Report
W Go to OS-8 keyboard monitor; save swap area
X Go to OS-8 keyboard monitor without save
Dnn Console output to terminal device code "nn"
Lnn Console output on LE8 / LP05 device code "nn"
Tnn Console input from keyboard device code "nn"
(%)B Build Exerciser
(%)P Punch or Save Exerciser
(%)ES Print remaining empty job slots under builder
PATCHES to DECX8
The following patches are incorporated into the program "DECX8.SV" on
the NED Diagnostic System. These allow the building and use of DECX8 on a
system that has no hardware switch register.
Location Old Value New Value Reason
________ _________ _________ ______
00200 7402 7000 remove halt
00201 7704 1265 standard device code
00210 7402 7000 remove halt
00211 7704 1366 standard device code
for the RKS8E module
16334 7402 7000 or hit CONTINUE
for ".BX" default extension
16034 0216 0230
The following locations can be patched using the ^O(dt) feature of the
DECX8 monitor to simulate the action of the front panel Runtime Switch
Register Options. Set the appropriate location to a value of 7340 to set the
bit to a 1.
Bit Location Function
___ ________ ________
0 01675 Ring Queing
1 01511 User or Exec mode
1 13071 user mode
2 11713 enable or disable all status reports
3 11524 long or short status reports
3 11623 " " "
4 12000 inhibit rotation
4 12034 " "
5 01454 use of MQ
6 02704 action upon error return
to set bits 7 & 8
00 - do nothing
01 - locations 02633 and 02643 get 7340
10 - location 02643 gets 7340
11 - locations 02633, 02643, and 02723 get 7340
Feel free to contact me, David Gesswein djg@pdp8online.com with any questions, comments on the web site, or if you have related equipment, documentation, software etc. you are willing to part with. I am interested in anything PDP-8 related, computers, peripherals used with them, DEC or third party, or documentation.
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