User`s manual

BM - Block of Memory Move
3-13
3
PPC1-Bug>BM 21000 2100F 20000 <Return>
Effective address: 00021000
Effective address: 0002100F
Effective address: 00020000
PPC1-Bug>
PPC1-Bug>MD 20000:10;H <Return>
00020000 5448 4953 2049 5320 4120 5445 5354 2121 THIS IS A TEST!!
00020010 0000 0000 0000 0000 0000 0000 0000 0000 ................
PPC1-Bug>
Example 2: Patch assembly code in memory
For this example, assume that you had a short program in memory
at address 20000 (displayed with the MD command).
PPC1-Bug>MD 20000 2000F;DI <Return>
00020000 3C401000 ADDIS R2,R0,$1000
00020004 60420001 ORI R2,R2,$1
00020008 7C631378 OR R3,R3,R2
0002000C 7CA53214 ADD R5,R5,R6
PPC1-Bug>
To insert an ANDC between the OR instruction and the ADD
instruction, Block Move the object code down four bytes to make
room for the ANDC.
PPC1-Bug>BM 20008 20010 2000C <Return>
Effective address: 00020008
Effective address: 0002000F
Effective address: 0002000C
PPC1-Bug>
PPC1-Bug>MD 20000 20014;DI <Return>
00020000 3C401000 ADDIS R2,R0,$1000
00020004 60420001 ORI R2,R2,$1
00020008 7C631378 OR R3,R3,R2
0002000C 7C631378 OR R3,R3,R2
00020010 7CA53214 ADD R5,R5,R6
PPC1-Bug>
Enter the ANDC at address 20008 using the MM command.
PPC1-Bug>MM 20008;DI <Return>
00020008 7C631378 OR R3,R3,R2? ANDC R3,R3,R2 <Return>
00020008 7C631078 ANDC R3,R3,R2
0002000C 7C631378 OR R3,R3,R2? . <Return>
PPC1-Bug>