Welcome to the world of binary computer
Observation and Reflection:
Conversion between hexadecimal:
10 Hex: 0123456789
Two 229: 01
Octal: 01234567
Hex: 0123456789abcdef
In order not represent misunderstanding, after the binary add B, followed by the hexadecimal H,
Binary Decimal: 1011 rpm decimal 1 * 2 . 3 + 0 * 2 2 + 1 * 2 1 + 1 * 2 0 = 11
A representative of each digital is not the same, for example, in binary
4 represent 1101 8421
5 is not present on behalf 11111 168421
Switch 10 decimal figures represent the number of bits is multiplied by the respective corresponding, since only the binary 0 and 1, can be regarded as non-0, as there are 1, then put the corresponding digital summing to
For example: 11001 equivalent to 16 + 8 + 1 = 25,, 11 001 to decimal 25
10011 equivalent to 16 + 2 + 1 = 19,, 11 001 to decimal 19
Decimal into binary:
A number continue to take the remainder divided by 2 is the binary, why divided by 2, since the remainder is divided by two and only two possibilities 0 and 1, then we can form a binary
Then to a decimal number 70, to see if the composition can be a multiple of 2, you can quickly determine which 70 in binary, e.g.
Binary decimal digits corresponding to 6,432,168,421
70, there is a 64,70-64 6,6 = a 2, a 4, so 70 bit 1000110
Note that the above method is not suitable for more than 255 figures
Every party rank corresponding to 16: Hex
Hex decimal turn
E * = 16 for example e12H 2 + 16 *. 1 . 1 + 2 16 * 0 = 3602
Decimal turn a hexadecimal number can be divided by 16
Or watching a multiple of 16, similar to the above binary decimal ,,,, rapid conversion = 83 * 5 + 3 = 16 53
Hex quickly convert binary:
The 9-9A = 1001 1010 8421 1001 divided by hexadecimal decimal to binary A-to-10, 10 10 1010, 1010 is the hexadecimal into binary
That corresponds to the decimal number for each hexadecimal into binary, hexadecimal
Binary hex, it is imperative every four binary is converted to a hexadecimal
Get started compilation:
s the high and low frequency converted into binary numbers 0,1,0,1
Binary required readability into something, then appeared in assembly language
Machine instruction: 01001010110101 B
The machine instruction into high and low, the driving operation of the computer
Enter dosbox
The same string of hexadecimal numbers: + number + number of hexadecimal digits + + Some English words alphanumeric
073F: 0113 7400 SW 0115
Hexadecimal numbers translated into binary:
7400 machine instructions, assembler instructions behind, which is one to two
7 4 00 SW 0115
0111 0100 0000 0000
Compiler translation software, the assembly instructions translated by a compiler into machine instructions, of course, a different compiler language translation of nowhere
Assembly instructions translated by a compiler into a machine code or machine instructions
Directive tells the compiler is translation software, how to translate
In line with system * - * / compiler tube
Assembly instructions stored where? ? Most instructions operate on memory and main memory data stored in memory,
example:
Memory Number: 073F: 0244
Memory number is zero-based
dosbox -debug -u -d
D command interpretation and comparison instructions nowhere U
u see instruction machine instructions and assembler instructions
see instruction data d
The smallest unit of memory is a byte 74H 03H = 2 hexadecimal bits = 8 bits
1Bytes = 8bit 1bit = 1 binary bits Items 2
unit of measurement
For contact between the cpu and memory data communication i.e., it is necessary to know the memory number (address lines) (transport position), data (data line) (transmission data), read and write information (control line) (read or write judgment) ,
Address line :::
An address line only represents 0 or 1, the number of address lines determines how much you are able to find the address (addressability) 2 the n-
For example ten address lines, its addressing range 0 to 1023
Data line :::
How much time can pass digital (byte capacity),
:: :( control line control of the other components)
B800: 400 is a memory address as address modifications in existing
Data register, address register
DS ES SS CS is address information
Left for the segment address register, the address register is an offset to the right
Address registers cheap SP BP SI DI IP BX (BX can both special)
Address adder, the address calculation,
Segment address * 16 (10H) + offset = physical address
* 16 segment address = base address
Address = base address + offset physical address
8086cpu address bus 20, the address register can store 16 ,, that is offset worse
Examples: F230H segment address offset address C8H
F230 * 10H + C8H = F23C8 is the 20-bit address
Data Register:
AX BX CX DX
They may be divided from the upper eight bits and lower eight bits into AH AL register AX e.g.