KA825MA1
EK-KA825-MA-001
KA825 Maintenance Advisory
(FOR INTERNAL USE ONLY)
MARCH, 1987
1.0 Purpose of Document
This document provides a general description of the VAX 8250/8350
systems by stating only the differences from the VAX 8200/8300 systems.
It is intended as a guide to assist VAX 8200/8300 trained field service
engineers in the maintenance of the VAX 8250/8350 systems.
2.0 Product Description
2.1 VAX 8200/8300 and VAX 8250/8350 Differences Overview
The VAX 8250 and 8350 systems are enhanced systems giving around 20%
greater performance than the standard 8200/8300 systems. This has
been accomplished by installing a faster CPU module, the KA825, in
place of the KA820. This new module is a T1001-YA and is a faster
version of the T1001-00 module currently used for the KA820. Both
modules physically look the same, except that the T1001-YA contains
faster components and a faster clock crystal ( see Table 1 below ).
Architecturally, the KA820 and KA825 are identical. All registers
and console commands are identical for the KA825 as well. The
differentiating factor between the two CPUs is bit 23 of the SID
register (most significant bit in the major revision field) which is
set for a KA825.
2.2 CPU Differences
The differences between the KA820 and KA825 CPU module are
summarized in Table 1 below.
Table 1
-------
Elements | KA825 | KA820
----------------------------------------------------------------
CPU Module | T1001-YA | T1001-00
----------------------------------------------------------------
BI Clock | 200 nanoseconds | 200 nanoseconds
----------------------------------------------------------------
CPU Clock | 160 nanoseconds | 200 nanoseconds
----------------------------------------------------------------
Xtal | 50 MHz | 40 MHz
----------------------------------------------------------------
Cache/TB RAMs | 35 nanoseconds | 45 nanoseconds
----------------------------------------------------------------
V11 chip set | 160ns parts | 200ns parts
----------------------------------------------------------------
DC346 | date code 8644 min | all date codes
----------------------------------------------------------------
DC347 | date code 8649 min | all date codes
----------------------------------------------------------------
DC348 | date code 8644 min | all date codes
----------------------------------------------------------------
3.0 OPERATING SYSTEMS
3.1 VMS
The first version of VMS that will officially support the KA825
is version 4.5. However, the error logger in this version of VMS
will report the KA825 as a KA820. This will be fixed in version
4.6 of VMS.
3.2 ULTRIX-32
The first version of ULTRIX that will officially support the KA825
is version 2.0.
4.0 DIAGNOSTICS
Changes have been made to both the Diagnostic Supervisor, (EBSAA)
and the EEPROM Utility, (EBUCA) to support the KA825 CPU. These two
programs should be available in diagnostic release 28.
Until this happens, a utility program floppy disk containing both
the correct Diagnostic Supervisor, and EEPROM Utility program will
be found in the loose parts bag that ships with the 8250 and 8350
systems. Replace the Utility Program floppy in the Owner's Manual,
found in the software box, with this new floppy. Copy this new
Diagnostic Supervisor from the utility floppy into your diagnostic
account for use when running diagnostics on the system.
Also the Diagnostic Supervisor that is on the floppy marked "VAX
8200 Diag Super + Auto" needs to be updated. To do this delete the
old Diagnostic Supervisor "EBSAA.EXE" on the "VAX 8200 Diag Super +
Auto" floppy, and copy the new one from the utility floppy. Writeboot
will have to be run on this disk again to allow the Diagnostic
Supervisor to be booted. Invoke the Writeboot program by typing,
MC Writeboot. Then answer the target file question with the drive the
floppy is in, account and program name. As shown:
EX: CSA2:[sysmaint]EBSAA.EXE
The next question will be logical block number, which should be
answered 2. The last is starting address which should be answered,
10000.
The new revisions are as follows:
EBSAA Rev 10.6 min
EBUCA Rev 2.3 min
4.1 EBSAA
The changes made to the Diagnostic Supervisor are to the software
timing loop to compensate for the faster CPU speed.
NOTE
----
The human interface section of the Diagnostic
Supervisor has NOT been modified in this release
to understand KA825 as a legal CPU type. Therefore,
it must be attached as a KA820.
4.2 EBUCA
The EEPROM Utility program has been modified in this release
to understand the difference between KA820 and KA825 CPUs, and
report them appropriately.
Since it is the most significant bit (23) of the CPU revision
field in the SID register that determines the type of CPU, the CPU
revision will always be the decimal equivalent of the CPU revision
plus 16.
Table 2
KA825 at CPU revision A1
SID Bit Positions | 23 | 22 | 21 | 20 | 19 |
--------------------------------------------------
Register contents | 1 | 0 | 0 | 0 | 1 |
--------------------------------------------------
Bit weights | 16 | 8 | 4 | 2 | 1 |
--------------------------------------------------
Decimal value | 16 | 0 | 0 | 0 | 1 |
--------------------------------------------------
CPU rev field = 16 + 1 or 17
4.3 EBKAX
EBKAX version 1.5 will get a "Hard error while testing KA0. More
than one RX50 interrupt received." error in test 39 when run on
a KA825 CPU. This is caused by the speed increase of the KA825 CPU
coupled with the algorithm the diagnostic uses to service interrupts.
For the present time it is recommended that EBKAX version 1.3 be
used in place on EBKAX version 1.5. Version 1.3 does not contain
the tests that check the RX50 therefore this version will not see
the problem. EBKAX version 1.3 was distributed in prerelease B for
the KA820, kit part number; PR-FG87B-DE.
5.0 MICROCODE
The KA825 will ship with microcode revision 23.
6.0 MAINTENANCE
The VAX 8250/8350 system maintenance strategy is the same as
that established for the VAX 8200/8300 systems. All procedures
currently used for VAX 8200/8300 systems should be followed for
the VAX 8250/8350 systems.
7.0 SITE PREPARATION
The same site preparation procedures and considerations that were
established for the VAX 8200/8300 systems apply to the VAX 8250/8350
systems. These consist of site layout, electrical, and environmental
requirements.
8.0 INSTALLATION
If there is a KDB50 installed in the system, be sure it has a pass 5
BIIC. If it doesn't, you will see a memory illegal confirmation error
on booting the system. A pass 5 BIIC can be identified by the part
number, which is stamped in one of the corners of the BIIC chip. A
pass 4 has a part number of 324D; a pass 5 will be 324E. Otherwise,
the VAX 8250/8350 installation procedures will follow the same
procedures as those established for the VAX 8200/8300 systems.
9.0 CD KIT
There will be a new CD Kit generated that will contain the T1001-YA
module. The part number for this kit is A2-W1228-10.
10.0 DOCUMENTATION
Title Document Number
---------------------------------------------------
VAX 8200 Owner's Manual AZ-GN4AA-TE
VAX 8200 Installation Guide AZ-GN5AA-TE
VAX 8200 Minireference Manual AZ-GN6AA-TE
KA820 Processor Technical Manual EK-KA820-TM
VAX 8200 Field Maint. Printset MP01786-01
This current set of documentation for the 8200/8300 systems will
be updated to include the 8250/8350 systems. This updated documentation
should be available during Q1 of FY'88.