Programming with machine instructions and assembly instructions (1)

Experimental tasks

(1)

1. Write instructions to memory using the a command in the form of assembly instructions

Execute the Write command with the T command

2. Write the machine code with the e command

The result of execution is the same as the a command

(2)

Write instructions to a memory unit from 2000:0

Ax=1, using 8 times jmp to figure out 2 of the 8-time Square

(3)

The ROM on the motherboard of the PC is written with a production date, in some units of memory Fff00h~fffffh, find this date and try to change it

cannot be changed because C0000~FFFFF is a variety of ROM address spaces, readable only

(4)

Fill the memory with data from a cell that starts with b8100h

Cells starting from 0001:0000 are filled with no change in data

Because the data is written to the address a0000~bffff, the data is written to the video memory, which is output to the monitor

Experimental summary

R command: View, modify register contents

d command: View memory contents

E command: Modify the contents in memory

T command: Executes the instruction at the memory unit pointed to by the Cs:ip

A command: Write instructions to memory in the form of assembly instructions

A0000~BFFFF Memory address space

C0000~FFFFF all types of ROM address space (readable only)

Programming with machine instructions and assembly instructions (1)