Page ,132 Title Replacement system clock driver for clock boards using MM 58167 AN clock chip. comment $ This is an installable device driver to access the battery driven clock on I/O port. Use with AST or TECMAR clock boards. Specify which one you want in the 'MACROS' section. If the choice is not specified you will have assembly error messages. To use, assemble this cource file using MASM.EXE (Macro Assembler from Microsoft) then link it using DOS LINK.EXE and finally convert it to a .BIN file using DOS EXE2BIN.EXE. Rename the final file CLOCK.SYS. Use EDLIN.COM to create a file named CONFIG.SYS with the statement 'DEVICE = CLOCK.SYS'. It will then be loaded automatically at start-up time. Using the command file generated by this assembly code as a simple command will hang up the computer. When the object code generated by the Macro assembler from this source code is linked, a warning "No STACK segment" and a message "1 error detected" should be ignored. Variable names and labels start with a capital letter followed by italic characters. Macro assembler operators are in italics. 8086 microprocessor registers are in capital letters. The MM 58167 AN clock chip has 8 clock counters and 8 data registers for setting the alarm comparator. It does not provides any facilities for keeping track of the year or wether it is a leap year. Hence the maximum number of days in February is 28 (storing a 29 in the day of the month counter while the month counter is 2 will set the corresponding clock counters to March 1st). The maximum number of days in the other months are 30 or 31 depending on the month. To provide for these deficiencies, the year, a copy of the month and a leap year flag are stored in the data registers. Their use is explained in the subsequent program. Dr The Hung Luv, DMD. Montreal, Mar 84. Reviewed and modified by Pierre Caouette. <71426,1561> References: - Installable device drivers. p. 14-1 to 14-34. (In Disk Operating System. Ver. 2, (Boca Raton), Microsoft, 1983. XXII + discontinuous pagings.) - Broadwell, K. David. Real-time clocks and PC-DOS 2.0. Byte magazine, 9(1):442-450, Jan. 1984. - Product specification : MM58167 AN clock chip. National Semiconductor. End of comment $ ;-----------------------------------------------------------------------; ; Macros ; ;-----------------------------------------------------------------------; Status macro State,Err,Rc ifidn , or ES:word ptr Srh_sta_fld[BX],0100H endif ifidn , or ES:word ptr Srh_sta_fld[BX],0200H endif ifidn , or ES:word ptr Srh_sta_fld[BX],1000H endif ifnb or ES:word ptr Srh_sta_fld[BX],Rc endif endm ;**************************************************************************** ; Write '' after the statement 'ifnb' if you want the device driver ;installed for a Tecmar board. Otherwise just write '<>'. ifnb <> ;**************************************************************************** ; The following are macros to be used with a Tecmar clock board Valid_code_mcr macro Valid_code equ 0ABH ;Validate chip code. Can be set to any ; arbitrary value. endm Clk_base_port macro Clock_base_port equ 37DH ;Base port = clock board I/O address. Start ;with clock latch of Tecmar Board's. This port ;must be writen with the address of the data ;to be read or writen at "037F" location. ;To obtain the data I/O port address (this is ;the location to read or write the data ;specified at "037D") add 2 to the clock base ;port. endm Clock_access macro Tecmar_access proc near ; Procedure to read/write clock IC. AH=0 is read, any other value in AH is ;write. ; Data passed and returned in AL, DX=index register (clock latch). push AX mov AL,DL mov DX,Clock_base_port out DX,AL add DX,2 pop AX or AH,AH ;Read or Write? (Same as 'cmp AH,0') jnz IO_write in AL,DX jmp Terminate IO_write: out DX,AL Terminate: ret Tecmar_access endp endm Read macro mov AH,0 call Tecmar_access endm Write macro mov AH,1 call Tecmar_access endm else ;**************************************************************************** ; Write '' after the statement 'ifnb' if you want the device driver ;installed for an AST board. Otherwise just write '<>'. If another choice ;has already been made before, then this option is not valid. ifnb ;**************************************************************************** ; The following are macros to be used with an AST Tecmar clock board Valid_code_mcr macro Valid_code equ 0DEH ;Validate chip code. Can be set to any ; arbitrary value. 0DEH is used by ; the AST support programs Ver 4.0 endm Clk_base_port macro Clock_base_port equ 2C0H ;Base port = clock-calendar chip first I/O ; address on AST board. endm Clock_access macro Ast_access proc near ; Procedure to read/write clock IC. AH=0 is read, any other value in AH is ;write. ; Data passed and returned in AL, DX=index register (clock latch). add DX,Clock_base_port or AH,AH ;Read or Write? (Same as 'cmp AH,0') jnz IO_write in AL,DX jmp Terminate IO_write: out DX,AL Terminate: ret Ast_access endp endm Read macro mov AH,0 call Ast_access endm Write macro mov AH,1 call Ast_access endm endif endif ;-----------------------------------------------------------------------; ; Equates ; ;-----------------------------------------------------------------------; Srh equ 0 ;Static request header start Srh_len equ 13 ; " " " length Srh_len_fld equ Srh ; " " " " field Srh_ucd_fld equ Srh+1 ;Srh unit code field Srh_ccd_fld equ Srh+2 ;Srh command code field Srh_sta_fld equ Srh+3 ;Srh Status field Srh_res_fld equ Srh+5 ;Srh reserved area field ; Input/Output Buf equ 14 ;Offset into the requested block of ; data (buffer) transfer address Buf_len equ 4 ;Buffer length ; Initialization Br_addr_0 equ 14 ;Character device usually only sets ending Br_addr_1 equ Br_addr_0+2 ;address and returns Br_addr_len equ 4 ; Offsets from clock base port Ram_mo_ofst equ 9H ; " of month checker in RAM Ram_leap_ofst equ 8H ;This clock register only store the ; upper nibble (4 bytes) Ram_yr_ofst equ 0AH ; " of year in RAM Cntr_reset_ofst equ 12H ; " of reset (RAM reset is one up at 13H) Status_bit_ofst equ 14H ; " to status byte. Unreliable read = 80, ; Ok = 00 Valid_ofst equ 0BH ; " of validation code in RAM ; Miscellaneous Valid_code_mcr ;Defined in section 'macros'. Leap_code equ 10H ;Because only upper nibble is stored, 10H is ; would be retained No_clock_cntr equ 8H ;Number of clock counters on chip No_clock_RAM equ 2H ;Number of clock RAM stored in Clock_cntr ; Used in procedure Set_clock to ; calculate end address of Clock_cntr Clk_base_port ;Defined in section 'macros'. ;-----------------------------------------------------------------------; ; Structures ; ;-----------------------------------------------------------------------; cseg segment para public 'Code' Clock_cntr_type struc Ten_thous db ? ;Counter - 1/10,000 of seconds BCD Hunds db ? ;Counter - 1/100 and 1/10 seconds BCD Secs db ? ;Counter - seconds BCD Mins db ? ;Counter - minutes BCD Hrs db ? ;Counter - hours BCD Wek_day db ? ;Counter - days of the week BCD Day db ? ;Counter - days of the month BCD Mo db ? ;Counter - month BCD Leap_adj db ? ;RAM - leap year adjust flag Yr db ? ;RAM - year stored in RAM. Its offset is ; not continous with the counters. ; Care should be taken when writing it ; in RAM to use the Ram_yr_ofst. ;AST clock support programs store it in HEX ; so we use the same format Clock_cntr_type ends Clk proc far assume CS:cseg,ES:cseg,DS:cseg Begin: ;-----------------------------------------------------------------------; ; Special device header ; ;-----------------------------------------------------------------------; Next_dev dd -1 ;Pointer to next device header field. ; If no other device then Next_dev = -1 Attribute dw 8008H ;Attribute of clock device (specification ; of type of device) Strategy dw Dev_strategy ;Pointer to device strategy Interrupt dw Dev_int ;Pointer to interrupt handler Dev_name db 'CLOCK$' ;Device name db 2 dup(?) ;Filler for an extra 2 bytes because ; "device name" has 8 bytes Rh_off dw ? ;Request header offset Rh_seg dw ? ;Request header segment User_buf dd ? ;User transfer address ; Function table Funtab label byte dw Init ;Initialization -Used first time device is ; called dw Media_check ;(Block only) - Not used dw Build_bpb ; " - Not used dw Ioctl_in ;Ioctl input - Not used dw Input ;Input(read) = get the time/date dw Nd_input ;Non-destructive input (char only) ; - Not used dw In_stat ;Char only - Not used dw In_flush ; " - Not used dw Output ;Output(write) = set time/date dw Out_verify ;Output w/ verify - Not used dw Out_stat ;Char only - Not used dw Out_flush ; " - Not used dw Ioctl_out ;Ioctl ouput - Not used ; Local data block in DOS 2.0 format Clk_tbl label byte dw ? ;Days since 1-1-80 = 2 bytes db ? ;Minutes = 1 byte db ? ;Hours = 1 byte db ? ;1/100ths of seconds = 1 byte db ? ;Seconds = 1 byte ; Table of current clock values Clock_cntr Clock_cntr_type <> ;Allocates according to predefined ; structure. Look under ; "Structures" ;-----------------------------------------------------------------------; ; Local procedures ; ;-----------------------------------------------------------------------; In_save proc near ;Save caller's buffer address mov AX,ES:word ptr Buf[BX] mov CS:User_buf,AX mov AX,ES:word ptr Buf+2[BX] mov CS:User_buf+2,AX ret In_save endp Dec_hex proc near ; Converts small packed BCD to HEX. ; Variable passed and returned in AL. ; Registers BX, CL used. push AX mov CL,4 shr AL,CL pop BX mov BH,10 mul BH and BL,0FH add AL,BL ret Dec_hex endp Hex_dec proc near ; Converts HEX numbers up to 63H (99 dec) to BCD ; Variable passed and returned in AL. ; Registers BX, CL used. sub AH,AH mov BL,10 div BL mov CL,04 shl AL,CL xchg AL,AH or AL,AH ;BCD in AL ret Hex_dec endp Daysconv proc near ; Convert the date mm-dd-yy to its number of days since 1-1-80. ; yy is passed in Clock_cntr.Yr ; mm is passed in Clock_cntr.Mo ; dd is passed in Clock_cntr.Day ; number of days returned in first 2 bytes of Clock_tbl ; AX, BX, CX, DX are used. It is the responsibility of the caller to save ;them if they would be needed later. ; CX = daysleft. mov AX,365 xor BH,BH mov BL,Clock_cntr.Yr ;BL = yy mul BX ;DX + AX = 365 * yy mov CX,AX ;CX = 365 * yy, ignoring ; DX. I.e. any value over ; 65536. Calculations ; only valid for ; Clock_cntr.Yr < 179 mov AX,BX ;AL = yy or AL,AL ;Same as 'cmp AL,0' jnz Yr_not_nul dec CX ;If yy = 0 then CX = CX - 1 jmp Yr_nul Yr_not_nul: dec AX ;AL = yy - 1 Yr_nul: mov BL,4 div BL ;AL = yy - 1 DIV 4 xor AH,AH ;Clear remainder add CX,AX ;CX = daysleft + (yy - 1) DIV 4 xor AH,AH mov AL,30 mov BL,Clock_cntr.Mo mul BL ;AX = 30 * mm add CX,AX ;CX = CX + (30 * mm) mov AL,57 mul BL ;AX = 57 * mm mov BL,100 div BL ;AL = (57 * mm) DIV 100 xor AH,AH add CX,AX ;CX = CX + (57 * mm) DIV 100 sub CX,29 ;CX = CX - 29 mov AL,Clock_cntr.Day add CX,AX ;CX = CX + dd cmp Clock_cntr.Mo,2 ;If mm > 2 jbe Save_result mov AL,Clock_cntr.Yr ; then ... test AL,3 ;Same as 'mov BL,4' ; 'div BL' ; 'cmp AH,0' jnz Not_leap_yr ;If yy MOD 4 = 0 dec CX ; then CX = CX - 1 jmp Save_result Not_leap_yr: sub CX,2 ; else CX = CX - 2 Save_result: dec CX ;CX = CX - 1 (Adjust for DOS) mov word ptr [Clk_tbl[0]],CX ;Save result ret Daysconv endp Dateconv proc near ; Convert the number of days since 1-1-80 to MM-DD-YY. ; number of days is passedr in first 2 bytes of Clock_tbl ; yy is returned in Clock_cntr.Yr ; mm is returned in Clock_cntr.Mo ; dd is returned in Clock_cntr.Day ; AX, BX, CX, DX are used. It is the responsibility of the caller to save ;them if they would be needed later. ; CX = daysleft. mov CX,word ptr [Clk_tbl[0]] ;CX = days - 1 (as passed ; by DOS) mov BX,CX ;BX = days - 1 inc CX ;CX = days mov AX,50 mul BX ;DX + AX = (days - 1) * 50 mov BX,18265 div BX ;AX = [(days - 1) * 50] DIV 18263 mov Clock_cntr.Yr,AL ;Save yy push AX mov BX,365 mul BX ;AX = yy * 365 sub CX,AX ;CX = days - (yy * 365) pop AX ;AX = yy push AX or AL,AL ;Is yy = 0 ? jnz Yy_not_nul ; If yy = 0 then yy - 1 = 256. ; Not really what we want inc CX ;CX = CX + 1 jmp Yy_nul Yy_not_nul: dec AL ;AL = yy - 1 mov BL,4 div BL ;AL = (yy - 1) DIV 4 xor AH,AH sub CX,AX ;CX = CX - [(yy - 1) DIV 4] Yy_nul: add CX,29 ;CX = CX + 29 pop AX ;AX = yy test AL,3 ;If yy in AL is a leap year jnz Yr_not_leap ; BX = add_to_feb mov BX,1 ; then BX = 1 jmp If_past_feb Yr_not_leap: mov BX,2 ; else BX = 2 If_past_feb: mov AX,91 sub AX,BX ;AX = 91 - add_to_feb cmp AX,CX ;If daysleft > 91 - add_to_feb jge Cal_month add CX,BX ; then CX = CX + add_to_feb Cal_month: mov AL,33 mul CX ;AX = 33 * CX mov BX,AX ;BX = 33 * CX mov AX,CX ;AX = daysleft mov DL,3 div DL ;AL = daysleft DIV 3 xor AH,AH add AX,BX ;AX = (33 * CX) + ; (daysleft DIV 3) xor DX,DX mov BX,1019 div BX ;AX = [(33 * CX) + ; daysleft DIV 3)] DIV 1019 mov Clock_cntr.Mo,AL ;Save mm push AX mov BL,30 mul BL ;AX = 30 * mm sub CX,AX ;CX = CX - (30 * mm) pop AX ;AL = mm mov BL,57 mul BL ;AX = mm * 57 mov BL,100 div BL ;AL = (mm * 57) DIV 100 sub CL,AL ;CL = CL - (mm * 57) DIV 100 ;Daysleft should be small ; enough to fit in one byte ; i.e. CL mov Clock_cntr.Day,CL ;Save dd mov AL,Clock_cntr.Mo cmp AL,12 ;If mm > 12 jle Finished mov Clock_cntr.Mo,1 ; then mm = 1 inc Clock_cntr.Yr ; yy = yy + 1 Finished: ret Dateconv endp Clock_access ;Defined in section 'macros' New_year proc near ; Check for a "new year" and/or update month stored in RAM. ; The MM 58167 AN clock chip does not have a counter for the years nor does ;it provide for a way to know that a month reset to 1 has occured (after 12, ;the clock month counter resets to 1). This subroutine corrects this ;deficiency by checking if the month stored in the clock RAM the last time ;the clock was accessed has changed. If it has and month in counter is greater ;than month in RAM then it just updates the month. If month in counter is less ;than month in RAM it assumes that it is a new year and increment year in RAM ;by one. ; The AST clock programs store the month in RAM under HEX format. For ;compatibility this subroutine assume the same format. mov DX,Ram_mo_ofst Read ;AL = month in RAM ;*** add 'call Dec_hex' if BCD mov AH,Clock_cntr.Mo ;AH = month in clock counter cmp AH,AL jl New ;1 < 12 so it's a new year jg Update ;It's a new month ret ;Same old month - go back New: inc Clock_cntr.Yr ;((last year - 1980) + 1) mov AL,Clock_cntr.Yr ;Add 'call Hex_dec' if using BCD format mov DX,Ram_yr_ofst Write Update: mov AL,Clock_cntr.Mo;Update Month_ck on RAM ;Add 'call Hex_dec' if using BCD format mov DX,Ram_mo_ofst Write ret New_year endp Leap_adjust proc near ; If Leap_adj is set then it is a leap year. In a leap year 3-1-yy = 2-29-yy ;because the clock chip does not count over 28 for Feb. If the clock counter ;date is 3-1-yy, set the corresponding clock counter arrays to 2-29-yy. If ;the date is over 3-1-yy then decrement the number of days by 1. If the number ;of days is over 0 then convert days into BCD, clear Leap_adj and save ;these changes to clock. ; This procedure assumes you will access your clock at least once in the next ;10 months after Feb, of a leap year. If this is not the case then the day ;of the month, before Mar, of the following year will be late one day. ; When the clock is accessed after Feb during a leap year then the day ;is decremented by 1. If the resulting day is 0, the procedure Daysconv will ;still convert it correctly to the number of days but not saved on the clock ;chip. If it is not 0 then the result is saved to the clock and the Leap_adj ;flag cleared. ; The procedure is: ; if Leap_adj = 10 then ; if mm > 2 then ; if (mm = 3 and dd = 1) then ; mm = 2 ; dd = 29 ; else ; days = days - 1 ; if days <> 0 then ; Leap_adj = 0 ; Save days and Leap_adjust ; endif cmp Clock_cntr.Leap_adj,Leap_code jne Leap_exit cmp Clock_cntr.Mo,2 jle Leap_exit cmp Clock_cntr.Mo,3 jne Back_up_1_day cmp Clock_cntr.Day,1 jne Back_up_1_day mov Clock_cntr.Mo,2 mov Clock_cntr.Day,29 jmp Leap_exit Back_up_1_day: dec Clock_cntr.Day cmp Clock_cntr.Day,0 je Leap_exit xor AL,AL mov DX,Ram_leap_ofst Write mov AL,Clock_cntr.Day call Hex_dec mov DX,6H Write Leap_exit: ret Leap_adjust endp Adjust_leap proc near ; Reset Leap_adj to 0 ; If it is a leap year and the month < 3 then set the Leap_adj flag to 1 ; If it is the Feb 29th then set it to Mar 1st mov Clock_cntr.Leap_adj,0 cmp Clock_cntr.Mo,2 jg Adjust_exit xor AH,AH mov AL,Clock_cntr.Yr mov BL,4 div BL cmp AH,0 jne Adjust_exit mov Clock_cntr.Leap_adj,Leap_code cmp Clock_cntr.Mo,2 jne Adjust_exit cmp Clock_cntr.Day,29 jne Adjust_exit inc Clock_cntr.Mo mov Clock_cntr.Day,1 Adjust_exit: ret Adjust_leap endp Time_DOS proc near ; Pass hours, minutes, seconds and 1/100ths secs to DOS Clk_tbl lea DI,Clk_tbl[2] xor AH,AH mov AL,Clock_cntr.Mins stosb mov AL,Clock_cntr.Hrs stosb mov AL,Clock_cntr.Hunds stosb mov AL,Clock_cntr.Secs stosb ret Time_DOS endp Time_clock proc near ; Load time from DOS Clk_tbl into Clock_cntr table lea SI,Clk_tbl[2] xor AH,AH lodsb mov Clock_cntr.Mins,AL lodsb mov Clock_cntr.Hrs,AL lodsb mov Clock_cntr.Hunds,AL lodsb mov Clock_cntr.Secs,AL ret Time_clock endp Read_clock proc near ; Set up registers to read clock chip and store it in Clock_cntr table. ; Start reading from top of base address of chip (1/100,000 of seconds). push CS pop ES mov DX,Status_bit_ofst ;Read status bit 1rst time Read ; to clear it Retry: lea DI,Clock_cntr cld mov CX,No_clock_cntr Loadit: mov DX,No_clock_cntr sub DX,CX Read push CX call Dec_hex ;Convert from BCD to Hex stosb pop CX ;Restore counter loop Loadit ; Check for counter rollover during read (Status byte = 80H) mov DX,Status_bit_ofst Read test AL,AL jnz Retry ; Store Leap_adj in RAM into Clock_cntr table mov DX,Ram_leap_ofst Read ;Add 'call Dec_hex' if using BCD format stosb ; Store year in RAM into Clock_cntr table mov DX,Ram_yr_ofst Read ;Add 'call Dec_hex' if using BCD format stosb ; Routines to prepare data for transfer to DOS call New_year ;Check to see if it's a new year call Leap_adjust call Daysconv ;Number of days since 1/1/80 call Time_DOS ;Current time in Hex lea SI,Clk_tbl mov ES,CS:User_buf+2 ;Set destination (ES:DI) to mov DI,CS:User_buf ;caller's buffer push CS pop DS ;Establish source mov CX,6 ;6 bytes rep movsb ;Send information to buffer for "read" ret Read_clock endp Set_clock proc near ; Gets data from DOS, transform it into the corresponding date & sets chip. mov DS,CS:User_buf+2 ;Set source to caller's (DOS) mov SI,CS:User_buf ; buffer blk address lea DI,Clk_tbl push CS pop ES mov CX,6 ;Set up to move data from cld ; User_buf to Clk_tbl rep movsb ;Do it ; Calculate and load local clock chip table (structure) push CS pop DS ;Establish DS as this segment call Time_clock ;Load time call Dateconv ;Days to YY-MM-DD call Adjust_leap ; Writes data to chip starting from bottom of Clock_cntr table, i.e. from ;year,then leap_adj, then etc. lea SI,Clock_cntr+No_clock_cntr+No_clock_RAM-1H std lodsb ;Same as 'mov AL,Clock_cntr.Yr' ;Add 'call Hex_dec' if using BCD format mov DX,Ram_yr_ofst Write ;Store Clock_cntr.Yr into RAM lodsb ;Add 'call Hex_dec' if using BCD format mov DX,Ram_leap_ofst Write ;Store Clock_cntr.Leap_adj into RAM lodsb mov DX,Ram_mo_ofst Write ;Store Clock_cntr.Mo into RAM mov CX,No_clock_cntr;Prepare registers to set counters xor AH,AH Write_cntr: push CX ;Next routine takes care of counters mov DX,-1H add DX,CX call Hex_dec ;Change to BCD Write ;"Write" to chip pop CX lodsb ;Move next data to AL loop Write_cntr ;Loop until done ret Set_clock endp ;-----------------------------------------------------------------------; ; Device strategy ; ;-----------------------------------------------------------------------; Dev_strategy: mov CS:Rh_seg,ES ;Save segment of request header ptr mov CS:Rh_off,BX ;Save offset of same ret ;-----------------------------------------------------------------------; ; Device interrupt handler ; ;-----------------------------------------------------------------------; Dev_int: cld ; Preserve machine stateM push DS push ES push AX push BX push CX push DX push DI push SI ; Branch according to the function passed mov BX,CS:Rh_off ;Get request block address from where mov ES,CS:Rh_seg ; device strategy put it mov AL,ES:[BX]+2 ;Get function byte rol AL,1 ;Get offset into table lea DI,Funtab ;Get address of function table xor AH,AH add DI,AX jmp word ptr[DI] ; The following entries are not supported by this device Ioctl_in: Ioctl_out: Nd_input: In_stat: In_flush: Out_stat: Out_flush: Media_check: Build_bpb: Out_verify: ; Set status byte as "error, incomprehensible command" Status Done,Error,03 jmp Exit ; Input = read clock chip Input: call In_save ;Call initial save routine call Read_clock ;Read in that date/time mov BX,CS:Rh_off ;Restore ES:BX as request hdr ptr mov ES,CS:Rh_seg Status Done,NoError,0 jmp Exit ; Output = set time & date Output: call In_save ;Call initial save routine call Set_clock ;Set time & date mov BX,CS:Rh_off ;Restore ES:BX as request hdr ptr mov ES,CS:Rh_seg Status Done,NoError,0 jmp Exit ; Everybody's exit Exit: pop SI pop DI pop DX pop CX pop BX pop AX pop ES pop DS ret ; Intialize Init: push CS pop AX ;Copy current CS to AX add AX,offset Init mov ES:word ptr Br_addr_0[BX],0 mov ES:Br_addr_1[BX],AX ;Make that the break address ; Check verify Byte - Has some other software diddled the clock mov DX,Valid_ofst ;Port for verify RAM Read cmp AL,Valid_code ;Arbitrary validation code jz Fine ;Jump on Ok ; Reset chip, can't trust it mov AL,0FFH ;Reset all registers mov DX,Cntr_reset_ofst Write ;Reset all counters inc DX ;RAM (latch) reset address Write ;Now reset RAM mov AL,Valid_code mov DX,Valid_ofst Write ;Now validate RAM ; Everything is correct Fine: Status Done,NoError,0 jmp Exit Clk endp cseg ends end Begin ent to crash 10 times. � (You get a point every time your� opponent crashes.)