r (Register)

r[t][reg[=value]]
 

The r command displays the contents of one or more central processing unit (CPU) registers and allows the contents to be changed to new values. If you specify the reg parameter with the r command, the command displays the value of that register in hexadecimal format and prompts for a new value. If you specify a reg and a value, the command sets the register to the given value.

t

Displays registers in terse format.

reg

Specifies the register to be displayed. If you specify f or msw for reg, the debugger displays the flags in a row at the beginning of a new line and prompts for one or more flag values. If you omit reg, the debugger displays the contents of all registers and flags along with the next executable instruction.

value

Specifies the new value for the register. Can be a number or a combination of these flag values:

OV	Overflow set
NV	Overflow clear
DN	Direction decrement
UP	Direction increment
EI	Interrupt enabled
DI	Interrupt disabled
NG	Sign negative
PL	Sign positive
ZR	Zero set
NZ	Zero clear
AC	Auxiliary carry set
NA	Auxiliary carry clear
PE	Parity even
PO	Parity odd
CY	Carry set
NC	Carry clear
NT	Nested task switch (on and off)

TS	Sets the task switch bit. (MSW only)
EM	Sets the emulation processor extension bit. (MSW only)
MP	Sets the monitor processor extension bit. (MSW only)
PM	Sets the protected-mode bit. (MSW only)

Flag values can be in any order. You do not have to leave spaces between these values.

If you type more than one value for a flag or enter an invalid flag name, the flags up to the error in the list are changed and those flags at and after the error are not changed. In addition, the debugger display the message: "Bad Flag."

Setting the protected-mode bit from within the debugger does not set the target system to run in protected mode. The debugger simulates the setting. To configure the target system to run in protected mode, you would have to set the PM bit in the MSW register and reset the target system to restart in protected mode.

See also the .r command.