1747-ASB模塊,A-B使用尺寸
在這條消息之后，有一個延遲，允許您如果愿意，可以中止自動啟動過程。到在沒有自動啟動的情況下獲得控制，您可以按斷開鍵或軟件中止或重置開關。
5.然后實際輸入/輸出開始：程序指向將指定介質的卷ID加載到RAM中，然后控制傳遞給它。
自動引導由ENV中包含的參數控制命令這些參數允許選擇特定引導設備和文件，并允許啟動延遲編程。參考有關更多詳細信息，請參閱附錄A中的ENV命令。
1747-ASB模塊有兩個備用EPROM插槽XU3和XU4可用于攜帶用戶編程的EPROM。因此，您不必重新編程187Bug EPROM，以實現ROMboot功能。
ROMboot的一個用途可能是在非智能控制器模塊。NORB命令禁用作用ROMboot序列
1.ROMboot在通電時配置/啟用并執行（也可以在重置時）以兩種方式之一：a、 通過環境（ENV）命令（請參閱附錄A）b、 通過RB命令，假設EPROM（或可選模塊上的其他位置或VMEbus）來支持它。
2.如果安裝了ROMboot代碼，則會給出一個用戶編寫的例程控制（如果例程滿足格式要求）。用戶的ROMboot模塊通過ROMboot聯動，必須滿足四個要求：電源必須剛剛好應用更改此選項以響應任何重置。必須找到你的例行程序在MVME187 ROM內內存映射。將此更改為板載的任何其他部分內存，甚至非車載VMEbus內存。
ASCII字符串“BOOT”必須位于指定的內存范圍內。您的例程必須通過校驗和測試，這確保該例程真正打算在通電時接收控制。有關如何使用ROMboot的完整詳細信息，請參閱
摩托羅拉88K RISC CPU調試包用戶手冊。
Following this message there is a delay to allow you an
opportunity to abort the Autoboot process if you wish. To
gain control without Autoboot, you can press the BREAK key
or the software ABORT or RESET switches.
5. Then the actual I/O begins: the program pointed to within
the volume ID of the media specified is loaded into RAM and
control passed to it.
Autoboot is controlled by parameters contained in the ENV
command. These parameters allow the selection of specific boot
devices and files, and allow programming of the Boot delay. Refer
to the ENV command in Appendix A for more details.
ROMboot
There are two spare EPROM sockets, XU3 and XU4, available to
carry user-programmed EPROMs. Therefore, you do not have to
reprogram the 187Bug EPROMs in order to implement the
ROMboot feature.
One use of ROMboot might be resetting SYSFAIL* on an
unintelligent controller module. The NORB command disables the
function.
ROMboot Sequence
1. ROMboot is configured/enabled and executed at powerup
(optionally also at reset) in one of two ways:
a. By the Environment (ENV) command (refer to
Appendix A)
b. By the RB command assuming there is valid code in the
EPROMs (or optionally elsewhere on the module or
VMEbus) to support it.
2. If ROMboot code is installed, a user-written routine is given
control (if the routine meets the format requirements). For a user's ROMboot module to gain control through the
ROMboot linkage, four requirements must be met: Power must have just been
applied.
Change this to respond to any reset.
Your routine must be located
within the MVME187 ROM
memory map.
Change this to any other portion of the onboard
memory, or even offboard VMEbus memory.
The ASCII string “BOOT” must be located within the specified memory range.
Your routine must pass a checksum test, which ensures that this routine was really
intended to receive control at powerupFor complete details on how to use ROMboot, refer to the
Debugging Package for Motorola 88K RISC CPUs User's Manual.
