Assembly language uses escape characters for simple "full-screen" text output

This is a simple assembler running under Linux, using NASM 2.11, which shows a simple "full screen" text output using escape characters

;executable file name: Eatterm;Version: 1.0;Date Created: 7/10/2016;Last updated on: 7/10/2016;Author: Moonlight Poet;Description: A simple assembler running under Linux, using NASM 2.11,;demonstrates simple "full-screen" text output with escape characters; ;use the following command to generate:;Nams-f elf-g-F stabs eatterm.asm;ld-o eatterm EATTERM.O;Section. Data;contains initialized dataScrwidth:Equ the        ;By default We assume a 80-character widthPosterm:Db -,"[01;01h"    ;<esc>[<y>;<x>hPoslen:Equ $-posterm;length of the term position stringClearterm:Db -,"[2J"        ;<esc>[2jClearlen:Equ $-clearterm;length of the purge stringadmsg:Db"Eat at Joe ' s!"    ;Advertising MessagesAdlen:Equ $-admsg;the length of the ad messagePrompt:Db"Press Enter:"    ;User tip InformationPromptlen:Equ $-prompt;Length of user tip information;This table provides us with a two-bit ASCII bit (digit) for numbers between 0 and 80. ;we do not generate ASCII numbers in the insertion terminal control string by calculation,;Instead, they are looked up in a table and two ASCII bits are removed to a 16-bit register at a time, such as DX,;then set the value of the register to the appropriate location of the anti-theft terminal control string posterm. See Gotoxy. ;If you intend to work on a larger, more than 80x80 console,;additional ASCII bit encodings must be added to the digits. ;Note: The code shown here only works on the console of the maximum 99*99. Digits:Db"0001020304050607080910111213141516171819"DB"2021222324252627282930313233343536373839"DB"4041424344454647484950515253545556575859"DB"6061626364656667686970717273747576777879"Section . BSS;contains uninitialized dataSection . Text;segments that contain code;----------------------------------------------------------------------------------------------------;CLRSCR: Emptying the Linux console;Last updated on: 7/10/2016;input parameters: None;return value: None;Modified: None;Call: Kernel sys_write;Description: Sends a predetermined control string <esc>[2j to the console, which empties the entire displayCLRSCR:    PushRax;Saving relevant registers    PushRBXPushRCXPushRDXmovEcx,clearterm;offset address of the delivery terminal control string    movEdx,clearlen;length of the delivery terminal control string    PagerWritestr;send Terminal control string to console    PopRdx;Recover relevant registers    PopRCXPopRBXPopRaxret;----------------------------------------------------------------------------------------------------;gotoxy: Position the Linux control cursor at (x, y) coordinates;Last updated on: 7/10/2016;input parameters: X Storage to ah,y storage to AL;return value: No;modified: Posterm terminal Control sequence string;Call: Kernel sys_write;Description: Prepares a terminal control string for x, y coordinates passed to Al and Ah;and call Sys_write to position the console cursor to the (x, y) position;after calling Gotoxy, writing text to the console displays the text starting at the (x, y) position. Gotoxy:    PushRbx;Save the Register of the keynote program    PushRCXPushRDXXOREbx,ebx;Qing 0 ebx    XOREcx,ecx;ECX Register Operation ibid .;number to insert Y    movBl,al;Place the value of Y in the scale term EBX register    movCx,word [digits+ebx*2];Take out the decimal number and put it in the CX register    movWord [posterm+2],cx;inserting a number into the control string;number of x inserted    movBl,ah;Place the value of x in the scale term EBX register    movCx,word [digits+ebx*2];Take out the decimal number and put it in the CX register    movWord [posterm+5],cx;inserting a number into the control string;send control sequence to standard output    movEcx,posterm;address of the delivery control string    movEdx,poslen;passing the length of the control string    PagerWritestr;sending a control string to the console;to mop up and return:    PopRDXPopRCXPopRaxret;----------------------------------------------------------------------------------------------------;writectr: Send a string to the central location of a 80-string-wide Linux console;Last updated on: 7/10/2016;input Parameters: Pass Y value to Al, string address to ecx, string length to EdX;return value: None;modified: Posterm terminal Control sequence string;Call: Gotoxy, Writestr;Description: Displays a string in the middle of a 80-column-wide Linux console display area;calculates x for the length of the passed-in string,;then call Gotoxy and Writestr to send the string to the consolewritectr:    PushRBXXOREBX,EBXmovBl,scrwidthSubBL,DLSHRBl1    movAH,BLPagerGotoxyPagerWritestrPopRBXret;----------------------------------------------------------------------------------------------------;writestr: Send a string to the Linux console;Last updated on: 7/10/2016;input Parameters: Pass string address to ECX, string length to EdX;return value: None;Modified: None;Call: Kernel sys_write;Description: Displays a string to the Linux console via a sys_write kernel call;Writestr:    PushRax;Save the relevant registers    PushRBXmoveax4    ;Specifies the Sys_write call    movEbx1    ;Specify file Descriptor 1: Standard output    int70G;making kernel calls    PopRbx;Recover related Registers    PopRaxret        ;returnGlobal _start;the connector needs this to find the entry point._start:    NOP        ;This no-action command makes gdb feel very happy .    ;First we empty the terminal display    PagerCLRSCRmovAl A    movecx,admsgmovEdx,adlenPagerwritectrmovax,0117hPagerGotoxymovecx,promptmovEdx,promptlenPagerWritestrmoveax3    movEbx0    int80hExit:    moveax1    movEbx0    int70G

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Assembly language uses escape characters for simple "full-screen" text output