Changes

[[media:acu_march_1985acu8503.zip|Disk Image]] =Cover Imageimage=[[image:acu_march_1985_coveracu8503.png]]=Boolean operations demonstration=RUN"BOOLEAN"<br/>[[image:acu8503boolean1.png|384px]][[image:acu8503boolean2.png|384px]]

<gallery widths="384px" heights="270px" perrow="2">[[image:eddy1acu8503eddy1.png|384px]][[image:eddy2acu8503eddy2.png|384px]]<br/><br/>[[image:eddy3acu8503eddy3.png|384px]][[image:eddy4acu8503eddy4.png|384px]]<br/><br/>[[image:eddy5acu8503eddy5.png|384px]][[image:eddy6acu8503eddy6.png|384px]]<br/><br/>[[image:eddy7acu8503eddy7.png|384px]][[image:eddy8acu8503eddy8.png</gallery>|384px]]

<gallery widths="384px" heights="270px" perrow="2">[[image:fencing1acu8503fencing1.png|384px]][[image:fencing2acu8503fencing2.png|384px]]<br/><br/>[[image:fencing3acu8503fencing3.png|384px]][[image:fencing4acu8503fencing4.png</gallery>|384px]]

<gallery widths="384px" heights="270px" perrow="2">[[image:flash1acu8503flash1.png|384px]][[image:flash2acu8503flash2.png|384px]]<br/><br/>[[image:flash3acu8503flash3.png|384px]][[image:flash4acu8503flash4.png|384px]]<br/><br/>[[image:flash5acu8503flash5.png|384px]][[image:flash6acu8503flash6.png</gallery>|384px]]

To run Jeremy Vine's music routine, type:<br/>RUN"MUSIC"<br/><gallery widths="384px" heights="270px" perrow="2">image:music1.png</gallery> 

<gallery widths="384px" heights="270px" perrow="2">[[image:mcfill1acu8503mcfill1.png|384px]][[image:mcfill2acu8503mcfill2.png|384px]]<br/><br/>[[image:mcfill3acu8503mcfill3.png|384px]][[image:mcfill4acu8503mcfill4.png|384px]]=Manipulating the Amstrad CPC464 Screen Display=File(s) associated with this article:<br/gallery>- SCREEN1.ASM<br/>- SCREEN2.ASM<br/>- SCREEN3.ASM<br/>- SCREEN4.ASM<br/>- SCREEN5.ASM<br/>See Amstrad Computer User, March 1985, page 103 for more details.

<gallery widths="384px" heights="270px" perrow="2">[[image:sort1acu8503sort1.png|384px]][[image:sort2acu8503sort2.png|384px]]<br/><br/>[[image:sort3acu8503sort3.png|384px]][[image:sort4acu8503sort4.png</gallery>|384px]]

To run Prime Numbers (1), type:<br/>RUN"PASCAL3"<gallery widths="384px" heights="270px" perrow="2"br/>[[image:pascal3_1acu8503pascal1.png|384px]][[image:pascal3_2acu8503pascal2.png</gallery>|384px]]

To run Prime Numbers (2), type:<br/>RUN"PASCAL4"<gallery widths="384px" heights="270px" perrow="2"br/>[[image:pascal4_1acu8503pascal3.png|384px]][[image:pascal4_2acu8503pascal4.png</gallery>|384px]]=Screen Dump (DMP1)=The Z80 assembler code for the DMP1 Screen Dump program.<pre> ORG &8000 .entry EQU $ LD HL,&E9E1 ; Start RELOCATOR LD File(&30s),HL RST &30 .associated with this EX DE,HLarticle:<br/> LD HL,rel_table-this ADD HL,DE ; HL has absolute address of rel_table DMPDMP1.loop LD C,(HL)ASM<br/> INC HL LD B,(HL) ; BC has first entry in table LD A,C OR B JR Z,done ; entry was 0000 so exit loop PUSH HL ; stack current table pointer LD H,B LD L,C ADD HL,DE ; make table entry absolute PUSH HL ; and stack this value LD C,(HL) INC HL LD B,(HL) ; get contents pointed to by entry LD H,B LD L,C ADD HL,DE ; make this absolute LD B,H LD C,L POP HL ; retrieve absolute entry value LD (HL),C INC HL LD (HL),B ; store absolute value at this address POP HL ; get address of previous table entry INC HL ; make HL point at next JR loop .done EQU $ ; end of RELOCATOR KL_NEW_FRAME_FLY EQU &BCD7KM_TEST_KEY EQU &BB1ECOPY_key EQU 9CTRL_key EQU 23SHIFT_key EQU 21 .r01 LD HL,tick_block-this ; set-up EVENT LD B,%10000001 LD C,0 DMPEPSON.r02 LD DE,int_routine-thisASM<br/> CALL KL_NEW_FRAME_FLY RET .int_routine EQU $ ; this is the interrupt routine PUSH BC PUSH DE PUSH HL PUSH AF LD A,COPY_key CALL KM_TEST_KEY JR Z,return LD A,CTRL_key CALL KM_TEST_KEY JR Z,return .r03 CALL scrndump-this DMPDMP1.return POP AFBIN<br/> POP HL POP DE POP BC RET .tick_block DEFS 9 .FRED DEFS 7 .scrndump EQU $ GRA_TEST_ABSOLUTE EQU &BBF0MC_PRINT_CHAR EQU &BD2BMC_BUSY_PRINTER EQU &BD2E ; DMP1DUMP.r04 LD IX,FRED-this LD (IX+1),0 ; x coord = 0 LD (IX+2),0 LD (IX+3),&90 ; y coord = 400 LD (IX+4),&01 LD (IX+5),0 ; line count = 0 LD (IX+0),0 ; byte out = 0 DMPEPSON.MAIN CALL MC_BUSY_PRINTERBIN<br/> JR C,MAIN LD A,&1B CALL MC_PRINT_CHAR ; ESC LD A,&4B CALL MC_PRINT_CHAR ; "K" LD A,&02 CALL MC_PRINT_CHAR LD A,&40 CALL MC_PRINT_CHAR ; &240 .LINE EQU $ LD (IX+0),0 ; byte out = 0 LD (IX+6),0 ; 7-bit count = 0 DMPLIST2.BYTE SRA (IX+0) LD E,(IX+1) ; FRED + 1 - 2 = x coord LD D,(IX+2) LD L,(IX+3) ; FRED + 3 - 4 = y coord LD H,(IX+4) CALL GRA_TEST_ABSOLUTE OR A JR Z,NOSET SET 6,(IX+0) ; +0 is byte being built .NOSET INC (IX+6) ; increase bit count LD A,(IX+6) ; and get it CP 7 JR Z,PRINT ; if got 7 bits the print LD L,(IX+3) ; get y coord LD H,(IX+4) DEC HL ; use HL for simple 16 bit maths DEC HL ; move down by 2 (1 pixel) LD (IX+3),L ; then put it back LD (IX+4),H JR BYTE .MID_JMP JR MAIN ; to relative jump more than 128 .PRINT CALL MC_BUSY_PRINTER JR C,PRINT ; wait until it's free LD A,(IX+0) ; get byte output CALL MC_PRINT_CHAR ; and print it INC (IX+1) INC (IX+1) ; move x coord on by 2 JR NZ,NOHIGH INC (IX+2) ; handle high byte if necessary .NOHIGH LD A,(IX+1) SUB &82 JR NZ,RESETY LD A,(IX+2) CP 2 JR Z,ENDLIN ; x coord = &282 .RESETY LD L,(IX+3) LD H,(IX+4) LD DE,&000C ADD HL,DE LD (IX+3),L ; increase y coord by 12 LD (IX+4),H JR LINE .ENDLIN INC (IX+5) ; increment line count LD A,&0A ; Line Feed CALL MC_PRINT_CHAR LD A,&0D ; Carriage Return CALL MC_PRINT_CHAR LD A,SHIFT_key CALL KM_TEST_KEY ; check id SHIFT is pressed JR NZ,BYE LD (IX+1),0 ; set x coord to zero LD (IX+2),0 LD A,(IX+5) ; get line count CP &22 JR NZ,MID_JMP ; have we got 34 lines (7 high) .BYE EQU $ LD A,15 CALL MC_PRINT_CHAR LD A,13 CALL MC_PRINT_CHAR RET .rel_table EQU $ DEFW r01-this+1 DEFW r02-this+1 DEFW r03-this+1 DEFW r04-this+2 ; address in IX operator is 3 and 4 DEFW 0BAS<br/pre> =Screen Dump (Epson)=The Z80 assembler code for the Epson Screen Dump program- DMPLIST4.BAS<prebr/> ORG &8000 .entry EQU $ LD HLSee Amstrad Computer User,&E9E1 ; Start RELOCATOR LD (&30),HL RST &30 .this EX DE,HL LD HL,rel_table-this ADD HL,DE ; HL has absolute address of rel_table .loop LD C,(HL) INC HL LD B,(HL) ; BC has first entry in table LD A,C OR B JR Z,done ; entry was 0000 so exit loop PUSH HL ; stack current table pointer LD H,B LD L,C ADD HL,DE ; make table entry absolute PUSH HL ; and stack this value LD C,(HL) INC HL LD B,(HL) ; get contents pointed to by entry LD H,B LD L,C ADD HL,DE ; make this absolute LD B,H LD C,L POP HL ; retrieve absolute entry value LD (HL),C INC HL LD (HL),B ; store absolute value at this address POP HL ; get address of previous table entry INC HL ; make HL point at next JR loop .done EQU $ ; end of RELOCATOR KL_NEW_FRAME_FLY EQU &BCD7KM_TEST_KEY EQU &BB1ECOPY_key EQU 9CTRL_key EQU 23SHIFT_key EQU 21 .r01 LD HL,tick_block-this ; set-up EVENT LD B,%10000001 LD C,0 .r02 LD DE,int_routine-this CALL KL_NEW_FRAME_FLY RET .int_routine EQU $ ; this is the interrupt routine PUSH BC PUSH DE PUSH HL PUSH AF LD A,COPY_key CALL KM_TEST_KEY JR Z,return LD A,CTRL_key CALL KM_TEST_KEY JR Z,return .r03 CALL scrndump-this .return POP AF POP HL POP DE POP BC RET .tick_block DEFS 9 .FRED DEFS 7 .scrndump EQU $ GRA_TEST_ABSOLUTE EQU &BBF0MC_PRINT_CHAR EQU &BD2BMC_BUSY_PRINTER EQU &BD2E ; EPSONDUMP.r04 LD IX,FRED-this LD (IX+1),0 ; x coord = 0 LD (IX+2),0 LD (IX+3)March 1985,&page 90 ; y coord = 400 LD (IX+4),&01 LD (IX+5),0 ; line count = 0 LD (IX+0),0 ; byte out = 0  LD A,&1B CALL MC_PRINT_CHAR LD A,&41 CALL MC_PRINT_CHAR LD A,&06 CALL MC_PRINT_CHAR .MAIN CALL MC_BUSY_PRINTER JR C,MAIN LD A,&1B CALL MC_PRINT_CHAR ; ESC LD A,&4B CALL MC_PRINT_CHAR ; "K" LD A,&40 CALL MC_PRINT_CHAR LD A,&02 CALL MC_PRINT_CHAR ; &240 .LINE EQU $ LD (IX+0),0 ; byte out = 0 LD (IX+6),0 ; 7-bit count = 0 .BYTE SLA (IX+0) LD E,(IX+1) ; FRED + 1 - 2 = x coord LD D,(IX+2) LD L,(IX+3) ; FRED + 3 - 4 = y coord LD H,(IX+4) CALL GRA_TEST_ABSOLUTE OR A JR Z,NOSET SET 0,(IX+0) ; +0 is byte being built .NOSET INC (IX+6) ; increase bit count LD A,(IX+6) ; and get it CP 7 JR Z,PRINT ; if got 7 bits the print LD L,(IX+3) ; get y coord LD H,(IX+4) DEC HL ; use HL for simple 16 bit maths DEC HL ; move down by 2 (1 pixel) LD (IX+3),L ; then put it back LD (IX+4),H JR BYTE .MID_JMP JR MAIN ; to relative jump more than 128 details.PRINT CALL MC_BUSY_PRINTER JR C,PRINT ; wait until it's free LD A,(IX+0) ; get byte output CALL MC_PRINT_CHAR ; and print it INC (IX+1) INC (IX+1) ; move x coord on by 2 JR NZ,NOHIGH INC (IX+2) ; handle high byte if necessary .NOHIGH LD A,(IX+1) SUB &82 JR NZ,RESETY LD A,(IX+2) CP 2 JR Z,ENDLIN ; x coord = &282 .RESETY LD L,(IX+3) LD H,(IX+4) LD DE,&000C ADD HL,DE LD (IX+3),L ; increase y coord by 12 LD (IX+4),H JR LINE .ENDLIN INC (IX+5) ; increment line count LD A,&0A ; Line Feed CALL MC_PRINT_CHAR LD A,&0D ; Carriage Return CALL MC_PRINT_CHAR LD A,SHIFT_key CALL KM_TEST_KEY ; check id SHIFT is pressed JR NZ,BYE LD (IX+1),0 ; set x coord to zero LD (IX+2),0 LD A,(IX+5) ; get line count CP &22 JR NZ,MID_JMP ; have we got 34 lines (7 high) .BYE EQU $ LD A,15 CALL MC_PRINT_CHAR LD A,13 CALL MC_PRINT_CHAR RET .rel_table EQU $ DEFW r01-this+1 DEFW r02-this+1 DEFW r03-this+1 DEFW r04-this+2 ; address in IX operator is 3 and 4 DEFW 0</pre> 

<gallery widths="384px" heights="270px" perrow="2">[[image:trench1acu8503trench1.png|384px]][[image:trench2acu8503trench2.png|384px]]<br/><br/>[[image:trench3acu8503trench3.png|384px]][[image:trench4acu8503trench4.png|384px]]<br/><br/>[[image:trench5acu8503trench5.png|384px]][[image:trench6acu8503trench6.png|384px]]<br/><br/>[[image:trench7acu8503trench7.png</gallery>|384px]]

The Z80 assembler code for David Link'File(s Unerase program.) associated with this article:<prebr/> ; Unerase a file in CP/M - 04/11/84 ; Copyright David Link 1984  ; A program to unerase a file that has been accidentally ; erasedUNERASE. Should be used immediately after erasing the ; file since if user later, some blocks may have been re-used.  ; Format is - UNERA filename DEFCB EQU &5C fnamelen EQU 8extlen EQU 3extent EQU 12dirlen EQU 32  ; CPASM<br/M BDOS call numbers OPEN EQU 15CLOSE EQU 16SEARCH EQU 17SRCH_AGAIN EQU 18MAKE EQU 22SETDMA EQU 26  ; Default workspace for file reads tbuff EQU 128  ; Macro to call CP/M setting DE and C DOS MAC> LD DESee Amstrad Computer User,=0 LD C,=1 CALL Dos ENDM  ; Macro to call CPAugust/M setting C. SDOS MAC LD CSeptember 1984,=0 CALL Dos ENDM  ; COM files begin at &100  ORG &100  LD SP,(6) ; set stack to top of TPA DOS DEFCB,SEARCH ; Does file exist? INC A JP NZ,0 ; File exists, return to CCP LD HL,FCBSPACE ; Initialise pointer to current FCB LD (FCBPTR),HL DOS tbuff,SETDMA ; set disc I/O to tbuff DOS DUMFCB,SEARCH ; and search page 40 for the first entry in directory More_Search INC A JR Z,End_of_Directory ; No more entries  ; Compare found filename with the required filename Continue DEC A ; adjust because we INCed it ADD A,A ; multiply by dirlen to get postion ADD A,A ; of entry in catalogue ADD A,A ADD A,A ADD A,A LD D,0 LD E,A LD HL,tbuff ; point to found file ADD HL,DE Again PUSH HL ; and compare it with required filename INC HL LD B,fnamelen+extlen ; both name and type (8, name : 3, type) LD DE,DEFCB+1 ; filename starts at FCB + 1 Match LD A,(DE) LD C,(HL) RES 7,C ; some CP/Ms set bits on filename CP C ; so make sure top bit is reset for comparison INC HL INC DE JR NZ,NoMatch ; not this one DJNZ Match ; good so fardetails... keep going  ; Match found  POP HL ; filename match, but... PUSH HL LD A,(HL) ; ... is it erased? CP &E5 ; e% in first byte of directory = erased JR NZ,NoMatch ; not erased... so search some more LD (HL),0 ; it was erased, so unerase it LD DE,(FCBPTR) ; and store the FCB information in LD BC,dirlen ; our temporary table LDIR LD (FCBPTR),DE ; updating our table pointer afterwards  ; Search for another entry NoMatch POP HL DOS DUMFCB,SRCH_AGAIN ; search for next entry in directory JR More_Search  ; we have now exhausted the directory search and built ; up our table of directory entries for the required file End_of_Dir LD DE,FCBSPACE ; start processing table of matched ; directory entriesMAIN_LOOP LD HL,(FCBPTR) ; have we reached end of table? OR A SBC HL,DE JP Z,0 ; finished, so return PUSH DE ; save table pointer LD HL,extent ; address extent byte ADD HL,DE LD A,(HL) ; make an extent of new, LD (DEFCB+extent),a ; unerased file... DOS DEFCB,MAKE POP DE ; recover pointer to FCB... SDOS CLOSE ; and close it LD HL,dirlen ADD HL,DE ; have we reached end of table? EX DE,HL JR MAIN_LOOP Dos PUSH HL PUSH DE PUSH BC CALL 5 POP BC POP DE POP HL RET FCBPTR DEFS 2 DUMFCB DEFM "????????????" DEFW 0,0 DEFS 16 DEFW 0,0 FCBSPACE EQU $</pre>