Table of Contents
CPU
ace_mode
The CHARON-VAX emulated CPU is configured with the "ace_mode" parameter.
Two VAX CPU implementations are available: the standard VAX instruction decoder and the optional high performance Advanced CPU Emulation mode ("ACE"). The ACE option optimizes VAX instruction interpretation and significantly improves performance. It also requires approximately twice the host memory to store the optimized code.
ACE optimization is performed dynamically during execution. Since it does not need to write optimized code back to disk, ACE provides its full capability instantly. The optimization does not compromise VAX instruction decoding; CHARON-VAX remains fully VAX hardware compatible and completely transparent to the VAX operating systems and applications.
Both CPU implementations passed the HP VAX Architecture (AXE) tests, the standard qualification for VAX instruction execution correctness.
The default VAX CPU mode is determined by the specific CHARON-VAX product license.
| Parameter | ace_mode |
|---|---|
| Type | Boolean |
| Value | true or false. |
This statement enables ACE mode if the CHARON-VAX license permits it. If this statement is omitted from the CHARON-VAX configuration file and the license permits it, "true" is the default. Otherwise "false" is the default. For test purposes the ACE mechanism can be disabled with:
set cpu ace_mode=false |
set cpu ace_mode=true" is ignored when the license does not permit ACE operation.The CHARON-VAX log file displays the status of the ACE option.ACE mode is disabled when the host system does not meet the minimum physical requirements for operation. If the emulator appears not to run at its normal performance, check the log file for a change in ACE mode and verify that sufficient host resources, especially memory, are available.
RAM
The CHARON-VAX memory subsystem is permanently loaded and has the logical name "ram".
size
| Parameter | size |
|---|---|
| Type | Numeric |
| Value | Size of emulated memory in MB. |
Example:
set ram size = 512 |
The amount of memory is capped at a maximum, defined in the CHARON license key. If the host system cannot allocate enough memory to map the requested emulated memory, CHARON-VAX generates an error message in the log file and reduces its effective memory size.
The following table lists the values of emulated RAM for various hardware models of virtual VAX systems:
| Hardware Model | RAM size (in MB) | |||
|---|---|---|---|---|
| Min | Max | Default | Increment | |
| MicroVAX_II | 1 | 16 | 16 | 1,8,16 |
| MicroVAX_3600 | 16 | 64 | 16 | 16 |
| MicroVAX_3900 | 16 | 64 | 16 | 16 |
| VAXserver_3600 | 16 | 64 | 16 | 16 |
| VAXserver_3900 | 16 | 64 | 16 | 16 |
| VAXserver_3600_128 | 32 | 128 | 32 | 32 |
| VAXserver_3900_128 | 32 | 128 | 32 | 32 |
| MicroVAX_3100_Model_96 | 16 | 128 | 16 | 16 |
| VAXstation_4000_Model_90 | 16 | 128 | 16 | 16 |
| VAX_4000_Model_106 | 16 | 128 | 16 | 16 |
| VAX_6000_Model_310 | 32 | 512 | 32 | 32 |
| VAXserver_3600_512 | 32 | 512 | 32 | 32 |
| VAXserver_3900_512 | 32 | 512 | 32 | 32 |
| MicroVAX_3100_Model_98 | 16 | 512 | 16 | 16 |
| VAX_4000_Model_108 | 16 | 512 | 16 | 16 |
| VAX_4000_Model_700 | 64 | 512 | 64 | 64 |
| VAX_4000_Model_705 | 64 | 512 | 64 | 64 |
| VAX_6610 | 128 | 3584 | 128 | 128 |
| VAX_6620 | 128 | 3584 | 128 | 128 |
| VAX_6630 | 128 | 3584 | 128 | 128 |
| VAX_6640 | 128 | 3584 | 128 | 128 |
| VAX_6650 | 128 | 3584 | 128 | 128 |
| VAX_6660 | 128 | 3584 | 128 | 128 |
TOY
CHARON-VAX maintains its time and date via the "toy" (time-of-year) component. In order to preserve time and date while a virtual system is not running, the TOY component uses a binary file on the host system to store date and time relevant data. The name of the file is specified by the “container” option of the "toy" component.
container
| Parameter | container |
|---|---|
| Type | Text string |
| Value | Specifies a name of a file in which CHARON-VAX preserves time and date during its “offline” period. This file also keeps some console parameters (such as default boot device). By default it is left unspecified.
|
It is recommended to specify the full path to the fileExample:
set toy container="/charon/my_virtual_system.dat" |
The CHARON-VAX time zone may be different from that of the host system. Correct CHARON time relies on the correctness of the host system time to calculate the duration of any CHARON “offline” periods. (i.e. while virtual system is not running). Every time CHARON comes on line it calculates a Delta time (the system time is used if there is no TOY file). Therefore, if the host system time is changed while CHARON is not running, the CHARON time may be incorrect when CHARON is restarted and the CHARON time must be set manually.
ROM
The System Flash ROM file conserves specific parameters between reboots.
container
| Parameter | container |
|---|---|
| Type | Text string |
| Value | Specifies the name of a file in which CHARON-VAX stores an intermediate state of its Flash ROM. This state includes, for example, most of the console parameters. By default it is left unspecified.
|
Example:
|
EEPROM
container
| Parameter | container | |
|---|---|---|
| Type | Text string | |
| Value | A string specifying a file name to store content of EEPROM. Example:
This command enables EEPROM parameters (e.g., default boot drive) to be automatically saved to a specified file. The EEPROM file is created in the directory in which CHARON-VAX starts and is created or overwritten each time any parameter relevant to EEPROM content is changed.
|
Example:
set eeprom container="/charon/my_virtual_system.rom"
|
Auto boot
CHARON-VAX systems may be configured to boot the operating system automatically at start up.
MicroVAX3100, VAXstation 4000, VAX6310 and VAX 4000
Those models boot automatically if correct boot flags are set (and saved in the VAX console files) using the following command:
halt
| Console Parameter | halt | |
|---|---|---|
| Description | Determines whether the MicroVAX3100, VAXstation 4000, VAX6310 and VAX 4000 boot automatically if correct boot flags are set (and saved in the VAX console files). The value is:
Example:
|
MicroVAX II, MicroVAX 3600/3900 and VAXserver 3600/3900
The ROM of the MicroVAX II, MicroVAX 3600, MicroVAX 3900, VAXserver 3600 and VAXserver 3900 does not allow the VAX console to accept the command setting "auto-boot". Instead, automatic boot on startup can be specified in the CHARON-VAX configuration file as follows:
bdr boot
| Parameter | bdr boot | |
|---|---|---|
| Type | Text string | |
| Value | Determines whether the MicroVAX II, MicroVAX 3600, MicroVAX 3900, VAXserver 3600 and VAXserver 3900 boot automatically if correct boot flags are set (and saved in the VAX console files).The value is:
Example:
|
VAX66x0
xmi boot
| Parameter | xmi boot | |
|---|---|---|
| Type | Text string | |
| Value | Determines whether the CHARON VAX66x0 startup procedure stops at the ">>>" prompt after self-tests. The values are:
Example:
The value "auto" enables automatic boot from a default boot specification previously configured in the VAX console.The value "manual" disables automatic boot once the self tests are passed. |