LOADING BINARY & BBCBASIC PROGRAMS FROM A PC DIRECTLY INTO THE EINSTEIN'S MEMORY
By Chris Coxall
Below are four bbcbasic listings. Three for BBCBASIC run on the Einstein and a MS-
Each of listings should be able to be selected by the mouse, copied to clipboard, pasted into Notepad and saved as text files.
HARDWARE REQUIREMENTS
A null modem link between the Einstein and PC. Hardware handshaking needed.
PC SOFTWARE
Win95/98 Hyper Terminal. Settings: the com port used, bits per second 9600, 8 data bits, 0 parity, 2 stop bits and flow control Hardware.
PROGRAMS
PCKEYS more about & LISTING
A BBCBBASIC program for the Einstein TC01 which when run will get bbcbasic keyboard input from a PC's win95/98 Hyper Terminal
Bbcbasic listings saved as text files on a PC can then be loaded into the Einstein by using "SEND TEXT FILE" from the Hyper Terminal's "TRANSFER" drop down menu.
PK.BBC download PK.txt is a bbcbasic program for the Einstein which when run will set both keyboard and screen output to the serial port and to a terminal program running on a PC.
REACOUT.BBC for the Einstein LISTING
When run this program will display the directory of all files on the Einstein's current default drive. It will prompt for a file name to be typed in. Ideally a *.com or binary file. File information, a "/" , then an ascii hex dump of the file sent followed by an "=" and more file information will be sent to the PC's Terminal. By using "CAPTURE TEXT" these files can be saved on a PC. Later they can be sent back to the Einstein loaded with "SRLRUN.COM" a com file created by "SRLRUN.BBC" a bbcbasic assembly program.
SRLRUN.BBC LISTING
A bbcbasic assembly program for the Einstein which will create "SRLRUN.COM" on the Einstein's default drive. This can be used to download back "*.com" files sent as an ascii text hex dump from the Einstein by READCOUT.COM.
SRLRUN.COM is loaded from the DOS prompt. It will just sit on the Einstein's screen until an ascii hex file created READCOUT.BBC is downloaded from a PC. It will translate the hex back into code, load it into the 'TRANSIENT PROGRAM AREA" call and run the program. No need to load it on an Einstein disc first. (will work with Xtal DOS version 1.11 but not with 2.05.)
SRLLOAD.COM. For loading a program into memory and not running create srlload.com by changing:
line 40 to
40 *SAVE SRLLOAD.COM E900 EA34
line 1520 to
1520 .LEP JP &0000
Srlload.com will load a transferred file into the Einstein then reboot. The file can then be run by the XTAL DOS command "GO" or put on disk by the XTAL DOS command SAVE <NUMBER OF BLOCKS> <FILENAME.EXT>.
SRL9000 is the same as SRLRUN but positions itself lower in memory and will work with Xtal DOS v. 2.05.
READCOUT.BBC for BBCBASIX run on the PC.
Readcout.bbc for the PC will open a binary Z80 file for the Einstein, i.e. a CP/M 2.2 com file downloaded from the net, and send it to SRLRUN or SRLLOAD running on the Einstein.
EXAMPLE DOWNLOAD for a CP/M program that will run on the Einstein.
MBASIC.COM at "http://www.retroarchive.org/cpm/lang/lang.htm"
Loading a bbcbasic listing from a text file on the PC. The Hyper Terminal can be used as keyboard input for the Einstein loaded with bbcbasic. This might be done by poking address &3a4b. It works with BBCBASIC Version 2.31 & XtalDOS 1.31 try the command below
?&3A4B=&A1 <ENTER>
Press some keys on the PC keyboard if the characters appear on the Einstein screen it has worked. Unfortunately although ok for key presses there is not any hardware handshaking and the transfer is too fast to make it suitable for downloading ascii text listings. There is no need to change baud rates. In the Hyper Terminal click the file menu, properties, the settings tab, the "ASCII setup" then change line delay to 5 milliseconds and character delay to 2 milliseconds.
Try sending PCKEYS listing from a text file to the Einstein. Type "LIST <ENTER> on the pc keyboard. If the listing looks ok on the Einstein screen. Type "RUN <ENTER> on the pc keyboard. You will have to look at the Einstein's screen or you could type *OPT 1 enter first for output to the terminal. Now go back to the Hyper Terminals ASCII setup and put line feed delay back to 0 milliseconds and character delay back to 0. Fast downloading should now be possible.
When run PCKEYS assembles a new machine code routine for hardware hand shaking above HIMEM and creates a jump from within the bbcbasic program.
Only run PCKEYS once otherwise HIMEM will keep being altered. Use "GOTO 10" for additional runs if desired. Clear PCKEYS from bbcbasic before sending basic listings files from the terminal. Programs loaded this way are put into bbcbasic as if typed on the keyboard. Old program line numbers which are not over written will be inserted into the downloaded program if the "NEW" command is not used first.
PCKEYS LISTING
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1 HIMEM=HIMEM- 10 GOSUB 70 20 PRINT"START " 30 GOSUB 80 50 STOP 70 BEGIN=HIMEM+1 80 CODE=BEGIN 90 P%=CODE 100 [ 110 PUSH AF 120 LD A,&27 130 OUT (&11),A 140 POP AF 150 LD (&FBB2),A 160 RST &08 170 DEFB &A1 180 PUSH AF 190 LD A,&07 200 OUT (&11),A 210 POP AF 221 RET 230 ] 240 SECOND=&3A47 241 CODE =SECOND 242 P%=SECOND 250 [ 1891 .SECOND CALL BEGIN 1892 RET 1900 ] 1910 RETURN 9000 REM goto 9010 to get input from the Einstein keyboard. 9010 SWOP=HIMEM+&B:?SWOP=&9C 9020 STOP 9100 REM goto 9110 to get input from PC keyboard. 9110 SWOP=HIMEM+&B:?SWOP=&A1 9120 STOP |
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10 REM READCOUT.BBC for the Einstein. 15 *.*.* 20 PRINT"TYPE FILE NAME TO READ" 30 INPUT A$:PRINT A$ 40 X=OPENIN(A$) 50 L=EXT#X:PRINT,"LENGTH ";L 60 PRINT"FILE NUMBER ";X 70 *OPT 1 80 PRINT A$,"BLOCKS ";L/256 81 REM delete rem from next line to send bbcbasic files as hex dumps for srlrun. 82 REM PRINT"LOAD BBC FILE AT HEX ~4000" 90 PRINT "hex dump for comfile \" 100 FOR I=1 TO L 110 Y=BGET# X 120 IF Y<&10 THEN PRINT"0"; 130 PRINT;~Y; 140 NEXT I 150 PRINT"=" 160 *OPT 0 170 CLOSE# X 180 PRINT:PRINT"FILE ";A$,"FILE NUMBER ";X,"LENGTH ";L 190 *OPT 1 200 PRINT:PRINT"FILE ";A$'"LENGTH ";L,"BLOCKS ";L/256 210 *OPT 0 |
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10 GOSUB 90 20 PRINT" START" 30 GOSUB 100 40 *SAVE SRLRUN.COM E900 EA34 70 STOP 90 BEGIN=&E900 100 CODE=&E900 110 P%=CODE 120 [OPT 1 130 .BEGIN LD BC,&0132; load BC the number of bytes to move. 140 LD DE,&E912; DE the address to move to. 150 LD HL,&0112; HL the address to move from 160 LDIR 170 JP LAD_ADDS; jump and run srlrun.com from its new location &E916. 180 NOP 190 NOP 200 NOP 210 RET 220 .RN DEFW &0100; store address to download starting at. 230 .SAFE DEFW &E8FE; fail safe to stop downloading over running SRLRUN.COM. 240 .LAD_ADDS LD HL,(SAFE); 250 LD DE,(RN) ; 260 CALL CHK_IN ; a routine to clear serial port buffer. 270 .CHK_START CALL RTS_ON ; handshaking allow PC to download. 280 CALL RECEIVE ; a routine to wait for next byte from serial input. 290 IN A,(&10) ; put serial input into A reg. 300 LD DE,(RN) ; load DE with address to load at. 310 CALL RTS_OFF ; set RTS on to hold flow of serial input from PC. 320 CP 126 ; compare A to ~" ascii 126 330 CALL Z,LAD_START ; routine to change DN store according to next 4 hex ascii bytes from serial input. 340 CP 92 ; compare A reg with / 350 LD DE,(RN) ; load DE new start address if changed. 360 CALL Z,LAD_PROG ; routine that converts and loads hex list into Einstein. 370 JR CHK_START ; loop back 380 RET 390 .CHK_IN PUSH AF ; routine to clear bytes not wanted for loading. 400 CALL RTS_ON 410 .CHKO IN A,(&10);clear buffer 420 IN A,(&11) ; read 8521A USART register. 430 BIT 1,A ; see if bit 1 = 0. 440 JR NZ, CHKO ; if not jump back and clear next byte. 450 POP AF 460 RET 470 .LAD_START PUSH AF ;routine to change address where code will be loaded. 480 CALL GT_BYTE ; download next two ascii hex bytes convert to real byte 490 LD D,A ; real byte returned in A reg. then loaded into D reg. 500 CALL H_PRINT ; routine convert real byte back to ascii and eco to PC terminal. 510 CALL GT_BYTE ; get next real byte. 520 LD E,A ; put second byte into E reg. 530 CALL H_PRINT ; echo second byte to PC. 540 LD (RN),DE ; store DE for new address to down load to. 550 POP AF 560 RET 570 .LAD_PROG ADD A,00 ; routine to load code into Einstein. 580 DEC A 590 DEC A 600 PUSH HL 610 PUSH DE 620 SBC HL,DE ; check to see if loading over runs. 630 JR Z NO_START ; if so jump to abort 640 POP DE 650 POP HL 660 CALL GT_BYTE; GET TWO ASCI HEX BYTES FOR REAL BYTE 670 LD (DE),A ; returned byte in A reg. loaded at address given by DE 680 CALL ECO ; echo loaded byte back to PC terminal. 690 INC DE ; get next address to load next byte. 700 JR LAD_PROG ; loop back 710 RET 720 .NO_START RET ; fail safe finish. 730 .GT_BYTE PUSH HL ; the routine to download two hex ascii bytes for real byte. 740 PUSH DE 750 CALL RTS_ON ; set handshaking on. 760 .BACK CALL RECEIVE ; routine to check if new byte has been received in 8251A buffer. 770 IN A,(&10) ; returned new byte in A reg. 780 CP 71 ; compare A to G 790 JR NC,BACK ; if A greater than 71- 800 CP 48 ; compare A to 0 810 JR C,BACK ; if A smaller than 48 jump back and get next byte. 820 CALL RTS_OFF ; hardware handshaking to hold down load from PC. 830 CP 61 ; compare A reg.(next byte) to = 840 JR Z,INEND ; if so program down load complete jump to end. 850 CP &40 ; compare A to @ ascii character before A 860 JR C,WR1 ; jump if A value less than &40- 870 AND &DF 880 SUB 07 ; standardize character code. 890 .WR1 ADD A,A ; shift A one hex digit left 900 ADD A,A ; so &30 becomes 00 910 ADD A,A 920 ADD A,A 930 PUSH HL ; store HL 940 LD L,00 950 LD H,00 960 LD H,A ; H=first hex digit * 16 970 CALL RTS_ON ; hand shaking allows serial input 980 .BACK2 CALL RECEIVE ; checks for new byte received. 990 IN A,(&10) ; serial input returned in A reg. 1000 CP 71 ; compare A to G . 1010 JR NC,BACK2 ; if G or Higher jump back and get next byte. 1020 CP 48 ; compare A to 0 1030 JR C,BACK2 ; if not 0 and ascii characters less than 48. 1040 CALL RTS_OFF ; hand shaking hold serial input. 1050 CP 61 ; compare A reg. to = . 1060 JR Z,INEND ; if so program download complete jump to end. 1070 CP &40 ;compare A to @ ascii character before A 1080 JR C,WR2 1090 AND &DF 1100 SUB 07 1110 .WR2 AND &0F ; consider second hex digit only. 1120 OR H ; combine with first hex digit- 1130 POP HL 1140 POP DE 1150 POP HL 1160 RET 1170 .ECO PUSH DE ;routine to echo byte loaded back to PC terminal. 1180 PUSH HL ; store HL 1190 LD H,D:LD L,E ; put address held in DE into HL. 1200 PUSH AF 1210 LD A,(HL) ; load last transferred byte into A reg. 1220 CALL H_PRINT ; routine to serial output A reg. value. 1230 POP AF 1240 POP HL ; restore HL value. 1250 POP DE 1260 RET 1270 .RECEIVE PUSH AF ; routine to check for new byte in 8251 USART. 1280 .CHK IN A,(&11) 1290 BIT 1,A ; bit 1=1 if fresh byte received. 1300 JR Z, CHK ; if bit 1=0 go back for new byte 1310 POP AF 1320 RET 1330 .RTS_ON PUSH AF ; hardware handshaking routine. 1340 LD A,&27 ; bits 0,1,4 and 5 set. bit 5 is request to send enabled. 1350 OUT (&11),A ; out A to 8521A reg. 1360 POP AF 1370 RET 1380 .RTS_OFF PUSH AF ; hardware handshaking routine to hold serial out put from PC. 1390 LD A,&07 ; bits 0,1,2 set and bit 5 reset to 0 1400 OUT (&11),A ;out A to 8521A reg. 1410 POP AF 1420 RET 1430 .END2 POP HL 1440 .INEND CALL CHK_IN 1450 POP HL ; restore as jumped out of loop. 1460 POP DE; restore as jumped out of loop. 1470 POP AF; restore as jumped out of loop. 1480 LD A,64; load A ascii @ 1490 CALL SEND; send to pc terminal to denote download complete. 1500 LD HL,&0100 ; 1510 LD (RN),HL ; reset load start address 1520 .LEP JP &0100 ; jump to run com prog.- 1530 RET 1540 .H_PRINT PUSH AF ; routine to turn real byte into two hex ascii bytes. 1550 AND &F0 ; isolates first digit. 1560 RRA ; move this 1570 RRA ; digit to 1580 RRA ; its proper position 1590 RRA ; in A reg. 1600 ADD A,&30 ; change to ascii character. 1610 CP &3A ; is digit between A and FOR 1620 JR C,HP_H ; 1630 ADD A,07 ; change to correct symbol if so. 1640 .HP_H CALL SEND ; serial output byte. 1650 POP AF ; retrieve original value AND 1660 AND &0F ; isolate second digit. 1670 ADD A,&30 ; change to ascii value for character. 1680 CP &3A ; 1690 JR C,HP_L 1700 ADD A,07 ; change to correct hex symbol. 1710 .HP_L CALL SEND ; serial output AND 1720 RET 1730 RET 1740 .SEND PUSH AF ; store A value 1750 .REP IN A,(&11)) ; read 8251A usart reg. 1760 BIT 0,A ; bit 0=1 if new byte ready to send. 1770 JR Z REP ; jump back if byte not ready. 1780 POP AF ; restore A 1790 OUT (&10),A ; serial output A 1800 RET 1810 ] 1820 RETURN |
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10 REM READCOUT.bbc for PC bbcbasix 20 REM to open a z80 com file and serial output it in hex. 30 REM to srlrun.com on the Einstein 40 PRINT:PRINT 50 *MODE COM1:9600,N,8,2 60 *.*.* 70 PRINT"TYPE FILE NAME TO READ" 80 INPUT A$:PRINT A$ 90 X=OPENIN(A$) 100 L=EXT#X:PRINT,"LENGTH ";L,"BLOCKS ";L/256 110 PRINT"FILE NUMBER ";X 120 *OPT 1 130 PRINT "zilog com file to output in hex \":REM \ needed to start loading. 140 FOR I=1 TO L 150 Y=BGET# X 160 *OPT 0 170 PRINT TAB(VPOS+13,POS+22);" "; I 171 N=GET(&03FE) 172 BT=N AND 16 173 IF BT =0 GOTO 171 180 *OPT 1 190 IF Y<&10 THEN PRINT"0"; 200 PRINT;~Y; 210 NEXT I 220 PRINT"=" 230 *OPT 0 240 CLOSE# X 250 PRINT:PRINT"FILE ";A$,"FILE NUMBER ";X,"LENGTH ";L |