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Note 20.0 MXV11-A, -B Differences No replies
JAWS::KAISER 84 lines 25-MAR-1985 09:24
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+---------------+ +-----------------+
| d i g i t a l | | uNOTE # 020 |
+---------------+ +-----------------+
+----------------------------------------------------+-----------------+
| Title: Differences between the MXV11-A and MXV11-B | Date: 10-JAN-85 |
+----------------------------------------------------+-----------------+
| Originator: Dave Smith | Page 1 of 2 |
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This MicroNote illustrates the features to consider when upgrading from
MXV11-AA/-AC to MXV11-BF multifunction boards or when choosing one in a
new configuration.
+-----------------------------------+----------------------------------+
| | |
| MXV11-A | MXV11-BF |
| | |
+-----------------------------------+----------------------------------+
| | |
| o Dual height form factor | o Dual height form factor |
| | |
| o 18-bit compatible only | o 18 or 22-bit compatible |
| | |
| o 2 SLU's (DLV11-J type) | o 2 SLU's (DLARTs) |
| | |
| o RAM: | o RAM: |
| 8 KB non-parity (MXV11-AA) | 128 KB non-parity |
| 32 KB non-parity (MXV11-AC) | |
| | |
| o ROM: 2 sockets (24-pin) | o ROM: 2 sockets (28-pin) |
| (for MXV11-A2 boot ROMS | (for MXV11-B2 boot ROMS |
| - cannot use MXV11-B2 ROMS) | - cannot use MXV11-A2 ROMS) |
| | |
+-----------------------------------+----------------------------------+
Notes:
The MXV11-B2 Boot ROMs are required for an LSI-11/73 based system to be
maintained under a DEC Field Service contract because these ROMs contain
cache diagnostics.
For a comprehensive list of Bootstraps and device support, refer to
MicroNote 15, entitled "Q-bus Hardware Bootstraps"
Since the ROM sockets on these boards may be used for user-written
application code as well as boot code, it is important to note what is
different on the two boards. Besides the sockets being of different
size, the ROM on the two boards has another difference. The ROM on the
MXV11-BF is window mapped and may be used under application control to
address up to 8 KB. The MXV11-A ROM is direct mapped and can only
address 256 bytes. Thus, an upgrade would require new ROMs and possible
Page 2
application recoding.
For more detailed information concerning MXV11-BF issues, refer to
MicroNote 19.
For more detailed information concerning MXV11-A issues, refer to the
archived MicroNotes listed in appendix A.
Summary:
When upgrading from the MXV11-A to the MXV11-BF or choosing the MXV11-BF
over the MXV11-A, three important features are obtained:
1) 22-bit compatibility - allows use in large memory systems
(The MXV11-BF memory can only be configured to start in the
lower 512 KB. It does, however, decode all 22 lines of
address which makes it usable in systems with up to 4 MB.)
2) More memory (although its non-parity feature creates some software
support issues if used with RSX or RSTS)
3) Support for boot ROMs that will boot MSCP devices such as the RX50
and RD51 and will provide cache diagnostics for the LSI-11/73.
