The presented device allows to exchange files between the PB-1000 and a PC through the serial port. It isn't compatible with the original FA-7/MD-100 interface. See this project for a compatible one.
The programs intentionally use only a subset of instructions accepted by the built-in assembler. The HD61 assembler can be also applied, but with the LEVEL 0 option.
The timing critical parts are marked by the number of clock cycles in the comments. Please don't change them (for example by replacing the JP instructions with more optimal JR) unless you know what you are doing!
pb1000s6.zip - both following programs stripped of comments and excessive whitespace
The program sends the contents of the sequential file of fixed name "MEMO" through the serial port. The transfer can be interrupted with the BRK key.
ORG &H7000 START &H7000 PST PD,&HC4 PST PE,&HC0 CAL &HB6EE ;copy the file name "MEMO" to WORK1 CAL &HE80F ;search for a file name in WORK1, any file type JP C,&HABE0 ;NF Error, file not found PRE IZ,$6 ;pointer to the directory entry DB 233,36,96 ;= LDM $4,(IZ+$30),4 ; $4,$5 = data begin pointer, $6,$7 = data end pointer LOOP1: SBCW $6,$4 RTN Z ;return when end of the file LD $0,$30 ;keyboard column KO1 CAL &H0625 ;select KO column $0, read KI row to $1,$2 BIU $1 ;KI12 -> Carry RTN C ;return when the BRK key was pressed LD $1,($4) ;$1 <- byte to send ADW $4,$30 ;increment the data pointer CAL RSWRT ;transmit the byte JR LOOP1 ; transmit the byte $1 through the port PD3 RSWRT: LD $2,&HFB ;2 stop bits BIUW $1 ;start bit INVW $1 GST IE,$0 PST IE,$31 ;disable interrupts ; bit loop, should take 379 clock cycles (=910000kHz/2400baud) RSWR1: LD $3,&H0C ;12 cycles BIDW $2 ;14 cycles, transmitted bit -> Carry ROU $3 ;9 cycles BIU $3 ;9 cycles BIU $3 ;9 cycles BIU $3 ;9 cycles PST PE,$3 ;9 cycles ; delay LD $3,11 ;12 cycles RSWR2: SB $3,1 ;12 cycles JP NZ,RSWR2 ;12 cycles NOP ;6 cycles ; next bit, $1,$2=&H0001 when all 11 bits have been transmitted SBCW $30,$1 ;17 cycles JR NZ,RSWR1 ;9 cycles PST IE,$0 ;restore interrupts RTN
The program reads data from the serial port to the sequential text file of fixed name "MEMO". The transfer is terminated upon reception of an EOF character (code &H1A), or when the BRK key was pressed, or when transmission error occurred.
Binary files can be transferred as a text (either as a list of values following the DATA statement in a BASIC program, or in the PBF hex format), then converted to the destination format. Suitable conversion programs TRANS and PBFTOBIN are provided with the HD61 assembler.
ORG &H7000 START &H7000 PST PE,&HC0 CAL &HB6EE ;copy the file name "MEMO" to WORK1 CAL &HE80F ;search for a file name in WORK1, any file type CAL NC,&HE842 ;KILL, delete the file if exists CAL &HB1C2 ;NDFMK, create a sequential file PRE IZ,&H6945 DB 233,2,96 ;= LDM $2,(IZ+$31),4 ;$2<-MEMEN, $4<-DATDI GST IE,$1 PST IE,$31 ;disable interrupts PST IA,$30 ;select the KO1 keyboard column ; wait for the start bit LOOP1: GRE KY,$8 BIU $8 ;KI12 -> Carry JR C,EXIT ;return when the BRK key was pressed ; it should take ca. 1.5*379 clock cycles from this point up to BIT1 GPO $8 ;9 cycles ANC $8,&H10 ;12 cycles JR NZ,LOOP1 ;9 cycles ; start bit detected LDW $8,&H0818 ;23 cycles, $9 = bit counter, $8 = delay JR DEL2 ;9 cycles ; bit loop, should take 379 clock cycles from this point up to STORE LOOP2: NOP ;6 cycles LD $8,14 ;12 cycles, delay DEL2: SB $8,1 ;12 cycles JR NZ,DEL2 ;9 cycles ; it should take 379 clock cycles from this point up to STOP1 BIT1: GPO $8 ;9 cycles AN $8,&H10 ;12 cycles SBC $30,$8 ;12 cycles, received bit -> Carry ROD $6 ;9 cycles, $6 = received byte ; next bit SB $9,1 ;12 cycles JP NZ,LOOP2 ;12 cycles ; process the received byte STORE: SBC $6,&H1A ;12 cycles JR Z,EXIT ;9 cycles, EOF encountered SBCW $2,$4 ;17 cycles JR NC,OMERR ;9 cycles, out of memory PRE IX,$2 ;14 cycles LD $7,&H1A ;12 cycles, EOF character STW $6,(IX-$30) ;20 cycles, store the received character + EOF ADW $2,$30 ;17 cycles, increment the data pointer STW $2,(IZ+$31) ;20 cycles, MEMEN PRE IX,$4 ;14 cycles, DATDI LD $0,3 ;12 cycles STW $2,(IX+$0) ;20 cycles, end address of the file LD $8,6 ;12 cycles, delay DEL3: SB $8,1 ;12 cycles JR NZ,DEL3 ;9 cycles ; check the stop bit STOP1: GPO $8 AN $8,&H10 JR NZ,LOOP1 FRERR: PST IE,$1 ;restore interrupts JP &HAC30 ;FR error (framing error) OMERR: PST IE,$1 ;restore interrupts JP &HABBD ;OM error (insufficient memory) EXIT: PST IE,$1 ;restore interrupts RTN
Here is a link to a similar project using an integrated interface circuit (RS232 or USB) instead of discrete components. The provided software supports data transfer speed of 9600 bps. Please note that the author chose different PB-1000 port pins.