IS200STCIH6AED燃机模块,GE使用进展
内存要求197Bug的程序部分大约是1兆字节的代码，由下载、调试器和诊断包组成，包含完全在闪存中。MVME197LE上的闪存是从位置$FF800000开始映射。
197Bug需要至少64KB的连续读/写内存运转ENV命令控制该内存块的位置。不管在板载RAM的位置中，第一个64KB用于197Bug堆栈静态变量空间，其余保留为用户空间。
IS200STCIH6AED燃机模块每当MVME197LE重置，目标IP初始化为对应的地址并初始化目标堆栈指针到用户空间内的地址，使用目标伪堆栈指针（R31）设置为用户空间的顶部。终端输入/输出控制在提示下输入命令时，可能会出现以下控制代码：输入以进行有限的命令行编辑。观察任何197Bug命令的输出时，XON和XOFF可以输入对终端端口有效的字符来控制如果启用了XON/XOFF协议（默认），则输出。这些角色分别由197Bug初始化为^ S和^ Q，但可由用户使用PF命令。在初始化（默认）模式下，操作如下支持磁盘输入/输出197Bug可以通过与智能磁盘通信来启动磁盘输入/输出VMEbus上的控制器模块。197Bug内置磁盘支持设施包括命令级磁盘操作、磁盘输入/输出系统调用（仅通过一个由用户程序使用的陷阱（496指令）和定义的数据磁盘参数的结构。参数，例如映射模块的地址以及类型和连接到控制器模块的设备数量保存在表中197 UG。这些参数的默认值在通电和冷启动重置，但可以按照默认部分中的说明进行更改参数，在本章后面。附录B包含当前支持的控制器列表，以及每个控制器的默认配置列表。区块与扇区逻辑块定义了磁盘设备的信息单元。磁盘是197Bug将其视为划分为逻辑块的存储区域。默认情况下对于系统中的每个块设备，逻辑块大小设置为256字节。这个可以使用IOT命令在每个设备的基础上更改块大小。该部门定义了媒体本身的信息单元，由控制器。扇区大小因控制器而异，而可以使用IOT命令显示和更改特定设备。
Memory Requirements
The program portion of 197Bug is approximately 1 megabyte of code,
consisting of download, debugger, and diagnostic packages and contained
entirely in the flash memory. The flash memory on the MVME197LE is
mapped starting at location $FF800000.
197Bug requires a minimum of 64KB of contiguous read/write memory to
operate.
The ENV command controls where this block of memory is located. Regardless
of where the onboard RAM is located, the first 64KB is used for 197Bug stack
and static variable space and the rest is reserved as user space. Whenever the
MVME197LE is reset, the target IP is initialized to the address corresponding
to the beginning of the user space, and the target stack pointers are initialized
to addresses within the user space, with the target Pseudo Stack Pointer (R31)
set to the top of the user space.Terminal Input/Output Control
When entering a command at the prompt, the following control codes may be
entered for limited command line editing.When observing output from any 197Bug command, the XON and XOFF
characters which are in effect for the terminal port may be entered to control
the output, if the XON/XOFF protocol is enabled (default). These characters
are initialized to ^S and ^Q respectively by 197Bug but may be changed by the
user using the PF command. In the initialized (default) mode, operation is as
followsDisk I/O Support
197Bug can initiate disk input/output by communicating with intelligent disk
controller modules over the VMEbus. Disk support facilities built into 197Bug
consist of command-level disk operations, disk I/O system calls (only via one
of the TRAP #496 instructions) for use by user programs, and defined data
structures for disk parameters.
Parameters such as the address where the module is mapped and the type and
number of devices attached to the controller module are kept in tables by
197Bug. Default values for these parameters are assigned at power-up and
cold-start reset, but may be altered as described in the section on default
parameters, later in this chapter.
Appendix B contains a list of the controllers presently supported, as well as a
list of the default configurations for each controller.
Blocks Versus Sectors
The logical block defines the unit of information for disk devices. A disk is
viewed by 197Bug as a storage area divided into logical blocks. By default, the
logical block size is set to 256 bytes for every block device in the system. The
block size can be changed on a per device basis with the IOT command.
The sector defines the unit of information for the media itself, as viewed by the
controller. The sector size varies for different controllers, and the value for a
specific device can be displayed and changed with the IOT command.
