Disk I/O Support
Default 177Bug Controller and Device Parameters
177Bug initializes the parameter tables for a default configuration of controllers and devices (refer to Appendix C). If the system needs to be configured differently than this default configuration (for example, to use a 70MB Winchester drive where the default is a 40MB Winchester drive), then these tables must be changed.
There are three ways to change parameter table contents:
❏Using BO or BH. When you invoke one of these commands, the configuration area of the disk is read and the parameters corresponding to that device are rewritten according to the parameter information contained in the configuration area. This is a temporary change. If a
❏Using the IOT. You can use this command to reconfigure the parameter table manually for any controller and/or device that is different from the default. This is also a temporary change and is overwritten if a
❏Obtain the source. You can then change the configuration files and rebuild 177Bug using different defaults. Changes made to the defaults are permanent until changed again.
Disk I/O Error Codes
177Bug returns an error code if an attempted disk operation is unsuccessful.
Network I/O Support
The Network Boot Firmware provides the capability to boot the CPU through the ROM debugger using a network (local Ethernet interface) as the boot device.
The booting process executes in two distinct phases:
B |
