WRITING TO THE Z80 PIO CONTROLL PORT
FOR MODE 0 and MODE 1
WITH INTERRUPTS ENABLED

%VVXX1111 . Bits D3-D0  indicate "Set Mode".
Last 4 bits set to 1111 Signifies This Control Word is to set mode.
Bits D5 and D4 are ignored.
Bits D7 and D6 set to 01 sets PIO to mode 1 input
Bits D7 and D6 set to 00 sets PIO to mode 0 output

%VVVVVVV0 . Bit 0 set to 0 sets the low byte interrupt vector set by remaining bits.
D0 is used in this case as a flag bit which when low,
causes V7 through V1 to be loaded into the vector register.
0 in D0 Signifies This Control Word is an Interrupt Vector.
%00001100 interrupt vector low byte set to Hex 12.
HEX 12 is the low byte of a scratch pad address given by the Einstein's Machine Operating System at bootup.
The high byte needs to be in the Z80's I register. This is fixed to HEX FB by the Einstein at bootup.

%VVVVV111
Bits 0, 1 and 2 set to 111 This Signifies Control Word  is to set interrupt.
%10000111 Bit 7 set to 1 enables interrupts.

A pdf user manual for the Z80 PIO can be downloaded here.

The BBCBASIC programs for the Einstein's a user port U_IN_EN.BBC and U_OUT_EN.BBC have been put into an Einstein Disk Image.Download here.   
A 3.5 inch Einstein floppy can be made from the image in a PC floppy drive with
CPCDiskXP software DOWNLOAD HERE.

Files in the disk image can be extracted from the image into PC folder using EDIP
SEE PAGE

PROGRAM LISTINGS

BBCBASIC FOR WINDOWS       *|          XP_IN.BBC       *|PC WINDOWS PROGRAM TO RUN IN BBCBASIC FOR WINDOWS       *|Windows BBC4W program XP_IN_large.BBC  works with       *|U_OUT_EN.BBC running in the Einstein       *|       *|It works in conjunction with the Einstein       *|with linked PC ECCP printer port with the user       *|port on the Einstein. It will output data bytes       *|to the program U_IN_EN.BBC running on the Einstein.       *|       *|         WIRING EINSTEIN USER PORT       *|PC data lines D0 to D7 to Einstein D0 to D7       *|PC strobe to Einstein STB       *|PC acknowledge to Eistein RDY.       *|Plus one or more ground lines.       *|       *|       *|NEXT LINES CHECK TO SEE IF WINIO FILES ARE IN THE SAME DIRECTORY       SYS "GetFileAttributesA", "winio.vxd" TO ret%       IF ret%=-1 PRINT "ERROR winio.vxd not in directory "'@dir$:STOP ELSE PRINT"winio.vxd ok"       SYS "GetFileAttributesA", "winiov1.sys" TO ret%       IF ret%=-1 PRINT "ERROR winio1.sys not in directory "'@dir$:STOP ELSE PRINT"winiov1.sys ok"       SYS "GetFileAttributesA", "winiov1.dll" TO ret%       IF ret%=-1 PRINT "ERROR winio1.dll not in directory "'@dir$:STOP  ELSE PRINT"winiov1.dll ok"       *|NEXT TWO LINES TO SHUT DOWN WINIO ON PROGRAM ERRORS AND AT CLOSE       *|IF WINIO IS NOT CLOSED IT WILL NOT ALLWAYS INSTALL AGAIN WITHOUT A REBOOT       ON CLOSE  SYS ShutdownWinIo% :PRINT:REPORT:STOP       ON ERROR  SYS ShutdownWinIo% :PRINT:REPORT:STOP       datap%=&378:              *|PRINTER LPT1 PORTS       status%=&378+1:           *|       controll%=&378+2:         *|       eccport%=&378+&402:       *|       DIM  dataport% 1:         *|MEMORY LOCATIONS TO STORE       DIM eccp% 1   :           *|PRINTER PORT READ AND WRITE BYTES       DIM statusp% 1 :          *|FOR WINIO SYSTEM CALLS       DIM controllp% 1:         *|SEE HELP Input/output using WINIO             *|             ******************************       *|         **************************************       *|     ******** LOADS THIRD PARTY WINIO LIBRARY *******       *|     FILES  WINIO.DLL, WINIO.SYS and WINIO.VXD must be in the       *|   same directory (folder) as the executable program using them.       *|Note to install WINIO IN 2000 and XP administrative privileges ARE NEEDED       *|****************************************************************************       SYS "LoadLibrary", "WINIO.DLL" TO winio%       IF winio% = 0 ERROR 0, "Could not load WINIO"       SYS "GetProcAddress", winio%, "InitializeWinIo" TO InitializeWinIo%       SYS "GetProcAddress", winio%, "ShutdownWinIo" TO ShutdownWinIo%       SYS "GetProcAddress", winio%, "GetPortVal" TO GetPortVal%       SYS "GetProcAddress", winio%, "SetPortVal" TO SetPortVal%       SYS InitializeWinIo% TO ok%       IF (ok% AND 1) = 0 ERROR 0, "Could not initialise WINIO"       *|       **********************************************************       *|       *|*****************************************************************************       PROC_set_byte_mode:      *|SETS UP ECCP PARALLEL FOR BYTE MODE       PRINT       PROC_controll_input:     *|SETS PRINTER PORT FOR OUT PUT       PRINT"RUN U_OUT_EN.BBC ON THE EINSTEIN THEN "       PRINT"PRESS ANY KEY TO RECEIVE INPUT FROM PRINTER PORT"       H=GET       PRINT''"TO CANCEL PRESS ESCAPE ON THE EINSTEIN KEY BOARD FIST  "'\       \"THEN ESCAPE ON THE PC KEYBOARD. "       *|                        **********************       *|                         ********************       *|               ****************************************       *|        *****************************************************************       *|********** MAIN PROGRAM FOR EXPORTING Bytes TO THE PRINTER PORT ******************       *|       *|       pollbyte=0: *| var to latch an acknowledge pulse       REPEAT         key$=INKEY$(0)         PROC_get         data%=?^dataport%         IF data%=13 PRINT CHR$(data%)         IF data% =>32 AND data%=<126 PRINT CHR$(data%);       UNTIL key$="A" OR key$="a"       SYS ShutdownWinIo%       STOP       *| ************************ END OF TO RECEIVE DATA  ********************       *|                   **********************       *|             *********DEF PROC_get************       *|WHEN THE LPT1 PORT HAS BEEN INITIATED AND WINIO INSTALLED       *|PROC_get IS THE ONLY PROCEDURE NEEDED FOR THE USER TO IMPORT A BYTE       *|FROM THE pc PRINTER PORT data%=?^dataport% PUTS IMPORTED BYTE IN data% VAR       DEF PROC_get       REPEAT:PROC_poll_ack:UNTIL pollbyte<>0       PROC_strobe_low       SYS GetPortVal%, datap%, ^dataport%, 1       pollbyte=0       PROC_strobe_high       ENDPROC       *| *******************************************************************************             *|   ************* PROC_set_byte_mode DOES WHAT IS SAYS ***************       DEF  PROC_set_byte_mode       SYS GetPortVal%, eccport%, ^eccp%, 1       byte=?^eccp%       byte=byte AND %00111111       byte=byte OR  %00100000       SYS SetPortVal%, eccport%, byte, 1       SYS GetPortVal%, eccport%, ^eccp%, 1       byte=?^eccp%       D$=FN_BIN(byte)       PRINT '"ENHANCED PARALLEL PORT"       PRINT"      BIT PATTEN                             ";D$       PRINT" Needed to set ECP port to byte mode.        %001XXXXX"       IF (byte AND %11100000)=%00100000 PRINT " BYTE MODE SET " ELSE PRINT"BYTE MODE NOT SET "       ENDPROC             *|   ************  PROC_controll_input  ********************       *|   ************  SETS LPT1 PRINTER PORT FOR INPUT       *|   ************  DISABLES INTERRUPTS       *|   ************  SETS STROBE LINE LOW (strobe hardware inverted)       DEF PROC_controll_input       SYS GetPortVal%, controll%, ^controllp%, 1       ctrl=ctrl OR %00100001        :*| ; set bits 0 to 1 inverted 1 sets STROBE line to low.       ctrl=ctrl AND %11101111       :*| ; bit 5 set to 1 for output       :                              *| ; bit 4 set to 0 no interrupts set       SYS SetPortVal%, controll%, ctrl, 1       SYS GetPortVal%, controll%, ^controllp%, 1       ctrl=?^controllp%       D$=FN_BIN(ctrl)       PRINT "CONTROLL PORT BIT PATTEN                     ";D$       PRINT " Needed bit 5 set to 1 for data outport      %XX1XXXXX"       PRINT " To set bit 0 to 1. Sets STROBE line to low. %XXXXXXX1"       PRINT " STROBE line hardware inverted"       PRINT " Bit 4 set to 0 for no interrupts set.       %XXX0XXXX"       IF (ctrl AND %00100000)=32 PRINT "          SET UP FOR IMPORT INSTALLED " ELSE PRINT "ERROR"       PRINT       ENDPROC                   DEF PROC_poll_ack       SYS GetPortVal%, status%, ^statusp%, 1       stat=?^statusp%       ack%=stat AND %01000000       IF ack%<>0 pollbyte=1       ENDPROC                   DEF PROC_strobe_high       SYS GetPortVal%, controll%, ^controllp%, 1       ctrl=?^controllp%       ctrl=ctrl AND %11111110        :*| ; set bit 0 to 0. Inverted-0 sets STROBE line to high.       SYS SetPortVal%, controll%, ctrl, 1       ENDPROC                   DEF PROC_strobe_low       SYS GetPortVal%, controll%, ^controllp%, 1       ctrl=?^controllp%       ctrl=ctrl OR %00000001        :*| ; set bit 0 to 1. Inverted-1 sets STROBE line to low.       SYS SetPortVal%, controll%, ctrl, 1       ENDPROC                   *| *************** FUNCTION PRINTS OUT BINARY STRING OF VAR *************       *| E,G VAR NUMERIC VALUE 7 WOULD RETURN STRING VAR %00000111       DEF FN_BIN(A%):LOCAL A$       REPEAT A$=STR$(A% AND 1)+A$:A%= A%>>>1:UNTILLENA$=8:A$="%"+A$       =A$       *| **********************************************************************

BBCBASIC FOR THE EINSTEIN    10 REM U_IN_EN.BBC EINSTEIN BBCBASIC PROGRAM    20 REM TEST PROGRAM TO IMPORT DATA BYTES    30 REM FROM THE USER PORT USING INTERRUPT HANDSHAKING    40 REM IMPORT CAN BE RECEIVED FROM A PC ECCP PRINTER PORT    50 REM RUNNING XP_OUT.BBC IN BBCBASIC FOR WINDOWS    60 REM ECCP SET TO BYTE MODE AND FOR IMPORT.    70 REM    80 REM *| WIRING EINSTEIN USER PORT/PC PRINTER PORT    90 REM *|PC data lines D0 to D7 to Einstein D0 to D7   100 REM *|PC strobe to Einstein STB   110 REM *|PC acknowledge to Eistein RDY.   120 REM *| PLUS ONE OR MORE GROUND   130 REM *   140 ON ERROR GOTO 1110   150 HIMEM=HIMEM-80   170 usrcon=&33   180 usrdata=&32   190 DIM code 80   200 code=HIMEM+1   210 PRINT "Assembling...code at &";~HIMEM+1   220 PRINT"PRESS ANY KEY TO CONTINUE ":H=GET   230 FOR pass=0 TO 1   240   P%=code   250   [OPT pass*3   260   .start_code   270   .flag DEFB 0   280   .intrrpt    ;interupt routine   290   PUSH HL   300   PUSH DE     ;save registers   310   PUSH BC   320   PUSH AF   330   LD HL,flag   340   RES 1,(HL)  ;at an interrupt byte at address flag has bit 1 set to zero.   350   POP AF   360   POP BC      ;retrieve registers   370   POP DE   380   POP HL   390   EI          ;enables interuppts   400   RETI        ;returns from interrupt routine.   420   .configpio      ;ROUTINE TO CONFIGER USER PORT FOR MODE 1 and INTERRUPS ENABLED   430     LD  A,&12       ;sets low byte of interrupt address   440     OUT (usrcon),A  ;writes to user port CONTROL reg &12 %00001100   450     ;sets low byte of interupt vector address   460     ;high byte of interupt vector address in Z80 I reg   470     ;set by Einstein at boot up to &FB.   480     LD  A,&4F       ;sets PIO to mode 1   490     OUT (usrcon),A  ;writes to Einstein user port reg &4F %01001111   500     LD  A,&87       ;enables interrupts   510     OUT (usrcon),A  ;writes to parallel user port control reg &87 %10000111   520     PUSH HL   530     LD HL,intrrpt   ; CASE reg HL address of interupt routine.   540         LD (&FB12),HL   ; CASE interupt address into interupt vector at &FB12.   550             POP HL   560             IM 2            ; ENABLE INTERRUPT 2 MODE   570             RET   580             .getbyte        ;ROUTINE TO IMPORT A SINGLE BYTE FROM THE USER PORT   590             PUSH HL   600             PUSH DE         ;save registers on the stack   610             PUSH BC   620             PUSH AF   630             LD HL,flag   640             .POLL           ;LOOP to poll bit 1 of flag set by interrupt routine.   650             LD HL,flag   660             BIT 1,(HL)   670             JR NZ,POLL      ;IF flag bit 1 not zero loop back.   680             IN A,(usrdata)  ;IF flag bit 1 zero get byte from user port into "A" register.   690             LD (imput_byte),A    ;Put byte value of imported byte now in "A" register   700             ;into memory location "imput_byte"   710             SET 1,(HL)      ;resets bit 1 of byte at memory location "flag" to 1.   720             POP AF   730             POP BC          ;retrieve registers from stack.   740             POP DE   750             POP HL   760             RET   770             .imput_byte DEFB 0   780             .end   790             ]   800           NEXT pass   810           CALL configpio   820           PRINT "CODE BEGINS AT ADDRESS &";~start_code   830           PRINT "END CODE ADDRESS &";~end   840           PRINT "flag=start_code+&";~flag-start_code   850           PRINT "configpio =start_code+&";~configpio-start_code   860           PRINT "getbyte =start_code+&";~getbyte-start_code   870           PRINT "imput_byte=start_code+&";~imput_byte-start_code   880           PRINT "CODE SIZE "; end-start_code   890           PRINT "PRESS ANY KEY TO START"   900           REM USER PROGRAMING CAN BE ADDED HERE   910           REM RECEIVED IMPORT BYTES FROM USER PORT   920           REM ARE FOUND BY CALLING getbyte THEN   930           REM PEEKING THE ADDRESS imput_byte   940           REM "n=?imput_byte" IN BBCBASIC   950           REM   960           REM IN THE EXAMPLE PROGRAM BELOW   970           REM BYTE VALUES 32 to 126 TO BE PRINTED   980           REM TO SCREEN AS ASCII CHARACTERS IN THE PC   990           REM WITH BBC4W RUNNING P_IN_WIN.BBC  1000           REM  1010           PRINT "PRESS ANY KEY TO RUN EXAMPLE PROGRAM"  1020           H=GET  1030           REPEAT  1040             D$=INKEY$(0)  1050             n=?imput_byte  1060             CALL getbyte  1070             IF n=13 PRINT  1080             IF n=>32 AND n=<126 PRINT CHR$(n);  1090           UNTIL D$="A" OR n=27  1100           STOP  1110           REPORT:PRINT "AT LINE ";ERL:STOP

BBCBASI FOR WINDOWS       *|XP_OUT.BBC is just small enough to run in       *|the trial BBC4W demo version.       *|If aditionl basic lines are added delete       *|comments before running in demo version       *|a NO ROOM error could mean rebooting       *|before WINIO will install again.       *|       *|          XP_OUT.BBC       *|PC WINDOWS PROGRAM TO RUN IN BBCBASIC FOR WINDOWS       *|Transfers bytes from the PC printer port to       *|Einsteins USER PORT.       *|Requires WINIO support files WINIO.VXD, WINIOV1.DLL       *|and WINIOV1SYS in the same folder as this program.       *|       *|Windows BBC4W program OUT_XP_large.BBC works with       *|U_IN_EN.BBC running in the Einstein to send bytes       *|from the PC printer port to the Einstein's user       *|port.       *|       *|         WIRING EINSTEIN USER PORT       *|PC data lines D0 to D7 to Einstein D0 to D7       *|PC strobe to Einstein STB       *|PC acknowledge to Eistein RDY.       *|Plus one or more ground lines.       *|       *|       *|This BBC4W Prog will work for win95/98 AND XP       *|The program is intended to poll acknowlede for       *|a pulse as output by RDY pin 5 of the       *|Einstein's Z80 PIO user port.       *|       *|       *|      WHEN Linked To The Einstein User Port       *|All handshaking lines work as expected and data       *|can be received by U_IN_EN.BBC when run on the Einstein.             datap%=&378:              *|PRINTER LPT1 PORTS       status%=&378+1:           *|       controll%=&378+2:         *|       eccport%=&378+&402:       *|       DIM  dataport% 1:         *|MEMORY LOCATIONS TO STORE       DIM eccp% 1   :           *|PRINTER PORT READ AND WRITE BYTES       DIM statusp% 1 :          *|FOR WINIO SYSTEM CALLS       DIM controllp% 1:         *|SEE HELP INDEX "Input/output using WINIO"       *|       *|NEXT LINES CHECK TO SEE IF WINIO FILES ARE IN THE SAME DIRECTORY       SYS "GetFileAttributesA", "winio.vxd" TO ret%       IF ret%=-1 PRINT "ERROR winio.vxd not in directory "'@dir$:STOP ELSE PRINT"winio.vxd ok"       SYS "GetFileAttributesA", "winiov1.sys" TO ret%       IF ret%=-1 PRINT "ERROR winio1.sys not in directory "'@dir$:STOP ELSE PRINT"winiov1.sys ok"       SYS "GetFileAttributesA", "winiov1.dll" TO ret%       IF ret%=-1 PRINT "ERROR winio1.dll not in directory "'@dir$:STOP  ELSE PRINT"winiov1.dll ok"       *|NEXT TWO LINES TO SHUT DOWN WINIO ON PROGRAM ERRORS AND AT CLOSE       *|IF WINIO IS NOT CLOSED IT WILL NOT ALLWAYS INSTALL AGAIN WITHOUT A REBOOT       ON CLOSE  SYS ShutdownWinIo% :STOP       ON ERROR  SYS ShutdownWinIo% :STOP       *|             ******************************       *|         **************************************       *|     ******** LOADS THIRD PARTY WINIO LIBRARY *******       *|     FILES  WINIO.DLL, WINIO.SYS and WINIO.VXD must be in the       *|   same directory (folder) as the executable program using them.       *|Note to install WINIO IN 2000 and XP administrative privileges ARE NEEDED       *|****************************************************************************       SYS "LoadLibrary", "WINIO.DLL" TO winio%       IF winio% = 0 ERROR 0, "Could not load WINIO"       SYS "GetProcAddress", winio%, "InitializeWinIo" TO InitializeWinIo%       SYS "GetProcAddress", winio%, "ShutdownWinIo" TO ShutdownWinIo%       SYS "GetProcAddress", winio%, "GetPortVal" TO GetPortVal%       SYS "GetProcAddress", winio%, "SetPortVal" TO SetPortVal%       SYS InitializeWinIo% TO ok%       IF (ok% AND 1) = 0 ERROR 0, "Could not initialise WINIO"       *|*****************************************************************************       *|       **********************************************************       *|       PROC_set_byte_mode:      *|SETS UP ECCP PARALLEL FOR BYTE MODE       PRINT       PROC_controll_output:    *|SETS PRINTER PORT FOR OUT PUT       *| *********************************************       *|                         ********************       *|               ****************************************       *|        *****************************************************************       *|********** MAIN PROGRAM FOR EXPORTING Bytes TO THE PRINTER PORT ******************       *|       *|       pollbyte=0: REM var to latch an acknowledge pulse       PRINT "      MAIN PROGRAM FOR EXPORTING BYTES TO THE PRINTER PORT "       PRINT "PRESS ANY KEY TO CONTINUE MAIN PROGRAM "'       H=GET       PRINT "RUN U_IN_EN.BBC on the Einstein. "''"TO CANCEL PRESS ESCAPE ON THE EINSTEIN KEY BOARD FIST  "'\       \" THEN ESCAPE ON THE PC KEYBOARD. "       *|REPEAT and FOR NEXT loop create an example program.       REPEAT         FOR i=32 TO 126           D$=INKEY$(0)           *|The next four lines get a single byte from           *|the printer port and set handshaking.           PROC_strobe_low           REPEAT:PROC_poll_ack:UNTIL pollbyte=1           SYS SetPortVal%, datap%, i, 1           pollbyte=0           PROC_strobe_high         NEXT i       UNTIL D$="A"       SYS ShutdownWinIo%       STOP       *| *******************************************************************************             *|       *|   ************* PROC_set_byte_mode DOES WHAT IS SAYS ***************       DEF PROC_set_byte_mode       SYS GetPortVal%, eccport%, ^eccp%, 1       byte=?^eccp%       byte=byte AND %00111111       byte=byte OR  %00100000       SYS SetPortVal%, eccport%, byte, 1       SYS GetPortVal%, eccport%, ^eccp%, 1       byte=?^eccp%       D$=FN_BIN(byte)       PRINT "ENHANCED PARALLEL PORT"       PRINT"      BIT PATTEN                             ";D$       PRINT" Needed to set ECP port to byte mode.        %001XXXXX"       IF (byte AND %11100000)=%00100000 PRINT " BYTE MODE SET " ELSE PRINT"BYTE MODE NOT SET "       ENDPROC             *|   ************  PROC_controll_output  ********************       *|   ************  SETS LPT1 PRINTER PORT FOR OUTPUT       *|   ************  DISABLES INTERRUPTS       *|   ************  SETS STROBE LINE LOW (strobe hardware inverted)       DEF PROC_controll_output       SYS GetPortVal%, controll%, ^controllp%, 1       REM PROC_ctrl       ctrl=ctrl OR %00000001        :*| ; set bits 0 to 1 inverted 1 sets STROBE line to low.       ctrl=ctrl AND %11001111       :*| ; bit 5 set to 0 for output       :                              *| ; bit 4 set to 0 no interrupts set       SYS SetPortVal%, controll%, ctrl, 1       SYS GetPortVal%, controll%, ^controllp%, 1       ctrl=?^controllp%       D$=FN_BIN(ctrl)       PRINT "CONTROLL PORT BIT PATTEN                     ";D$       PRINT " Needed bit 5 set to 0 for data outport      %XX0XXXXX"       PRINT " Needed bit 4 set to 0 for NO interrupts     %XXX0XXXX"       PRINT " To set bit 0 to 1. Sets STROBE line to low. %XXXXXXX1"       PRINT " STROBE line hardware inverted"       ENDPROC             DEF PROC_poll_ack       SYS GetPortVal%, status%, ^statusp%, 1       stat=?^statusp%       ack%=stat AND %01000000       IF ack%<>0 pollbyte=1       ENDPROC                   DEF PROC_strobe_high       SYS GetPortVal%, controll%, ^controllp%, 1       ctrl=?^controllp%       ctrl=ctrl AND %11111110        :*| ; set bit 0 to 0. Inverted-0 sets STROBE line to high.       SYS SetPortVal%, controll%, ctrl, 1       ENDPROC             DEF PROC_strobe_low       SYS GetPortVal%, controll%, ^controllp%, 1       ctrl=?^controllp%       ctrl=ctrl OR %00000001        :*| ; set bit 0 to 1. Inverted-1 sets STROBE line to low.       SYS SetPortVal%, controll%, ctrl, 1       ENDPROC                   *| *************** FUNCTION PRINTS OUT BINARY STRING OF VAR *************       *| E,G VAR NUMERIC VALUE 7 WOULD RETURN STRING VAR %00000111       DEF FN_BIN(A%):LOCAL A$       REPEAT A$=STR$(A% AND 1)+A$:A%= A%>>>1:UNTILLENA$=8:A$="%"+A$       =A$       *| **********************************************************************