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Date   : Wed, 16 May 1984 17:50:47-PDT (Wed)
From   : harpo!seismo!hao!kpno!terak!jb@Ucb-Vax.ARPA
Subject: Download Bootstrap

I doubt that this is the program referred to, but
will make it available as one solution to this
Catch-22 problem...


;         Copyright 1984 by John M. Blalock

;       ####################################
;       ##                                ##
;       ##         GETIT.ASM              ##
;       ##                                ##
;       ##      Written by:               ##
;       ##                                ##
;       ##          John M. Blalock       ##
;       ##          March 24, 1984        ##
;       ##                                ##
;       ####################################

;          Last updated May 15, 1984, JMB

; This  program  is a very simple CP/M terminal  and  ASCII 
; text   capture   program.    Once  customized  for   your 
; particular computer, it will enable you to communicate to 
; another computer via a serial port.   It is expected that 
; the serial port will be connected to a modem.  GETIT will 
; allow  you  to  transfer  ASCII  files  from  the  remote 
; computer  to  yours  and save them on disk as long as the 
; files  are no larger than the available  capture  buffer.  
; Longer  files  will  have to be broken  up  into  smaller 
; segments and recombined on your computer with PIP.

; Once you have established communications with the  remote 
; computer,  entering  Ctl-Y  from your console will  cause 
; GETIT  to start saving text sent from the remote computer 
; into  a RAM buffer that starts at  0100H.   This  capture 
; function can be toggled on and/or off by subsequent entry 
; of another Ctl-Y.  An ASCII BELL character is sent to the 
; console  when capture is toggled on,  and nothing is sent 
; when it is toggled off.

; Entering  Ctl-E  will cause GETIT to exit to  CP/M  after 
; first  telling  you the decimal number of  pages  in  the 
; capture buffer.   GETIT will also exit when the buffer is 
; filled.  An  X-OFF  (Ctl-S) is first sent to  the  remote 
; computer  that will stop further output by it as long  as 
; it supports the X-ON/X-OFF protocol.   The captured  data 
; will be in your RAM starting at 0100H and can be saved to 
; disk  by  entering SAVE nn FILENAME.EXT where nn  is  the 
; number of pages GETIT told you to SAVE.

; GETIT  is  purposefully  short and simple  to  facilitate 
; entry  of its source code from the keyboard.   Leave  out 
; the comments - you have them here.   Probably  the  first 
; thing for which you will want to use it (and perhaps  its 
; only  use)  is  to  download  a  better,   more   capable 
; communications  program.   But it does solve the Catch-22 
; problem of not being able to download any  communications 
; program  because  you don't have any to start  with.   If 
; MDM730.HEX is available on the remote  computer,  capture 
; it  with  GETIT,  LOAD  it,  and  now  you  have  a  good 
; communications program.

; GETIT  is released for use in the public domain for  non-
; profit usage only.   If it helps you sell your product, I 
; would like to share in the profits.  If you sell GETIT, I 
; want all the profits.   Any questions should be addressed 
; to John Blalock,  Blalock and Associates,  PO Box  39356, 
; Phoenix, AZ 85069.  Include an SASE if you want a reply.

; MODEM CONSTANTS - You will need to change these to  match
; your particular UART.  If your UART transmit buffer empty
; and/or receive data available bits are low  true,  you'll
; have to change the conditional jumps that test these bits
; from JNZ to JZ  and  from  JZ to JNZ.  The affected lines 
; are marked with an asterick (*) in the comments below.

MDATA   EQU     080H            ;MODEM DATA PORT
MSTAT   EQU     081H            ;MODEM STATUS PORT
TXRDY   EQU     001H            ;TX BUFFER EMPTY BIT
RXRDY   EQU     002H            ;RX DATA AVAILABLE BIT

; Equate DEST to 0100H bytes or more below  the CCP in your
; version of CP/M.   The  higher  it  is,  the  larger  the 
; capture buffer will be.  I have 52.5K bytes  available in
; the capture buffer  with  my  version  of  CP/M  and  the
; following DEST value.

DEST    EQU     0D300H          ;PROGRAM IS RELOCATED TO HERE

; The following equates shouldn't require any changes for a
; standard CP/M system.

BASE    EQU     0000H           ;CP/M BASE ADDRESS
BUFF    EQU     BASE+0100H      ;CAPTURE BUFFER START ADDRESS
BDOS    EQU     0005H           ;BDOS ENTRY ADDRESS
STACK  EQU     DEST+100H       ;GETIT TOP OF STACK
CAPT    EQU     'Y'-40H         ;CTL-Y = START/STOP CAPTURE
EXIT    EQU     'E'-40H         ;CTL-E = STOP, EXIT TO CP/M
BELL    EQU     07H             ;BEEP THE CONSOLE
CR      EQU     0DH             ;ASCII CARRIAGE RETURN
LF      EQU     0AH             ;ASCII LINE FEED

        ORG     BUFF            ;PROGRAM STARTS HERE

BEGIN   LDA     BASE+2          ;GET BIOS PAGE NUMBER AND
        STA     PCONST+2        ; PATCH PROGRAM WITH YOUR
        STA     PCONIN+2        ; BIOS ENTRY ADDRESSES
        STA     PCONOUT+2
        LXI    H,0000          ;CLEAR HL
        DAD    SP              ;ORIG SP TO HL
        SHLD   SPSAVE          ;SAVE FOR LATER
        LXI    SP,STACK        ;INIT STACK POINTER

INIT    ;Insert here any code required to initialize your
        ;UART if it is not already initialized by some 
        ;other program or your CP/M cold boot routine.

BMOVE   LXI     D,DEST          ;BLOCK MOVE DESTINATION
        LXI     H,START         ;FIRST ADDRESS TO MOVE
        MVI     C,PEND-START    ;NUMBER OF BYTES TO MOVE
MVLOOP  MOV     A,M             ;GET A BYTE
        STAX    D               ;MOVE IT
        INX     H               ;BUMP POINTERS
        INX     D
        DCR     C               ;COUNT THE BYTE
        JNZ     MVLOOP          ;LOOP 'TIL DONE
        JMP     GETIT           ;NOW GO RUN THE PROGRAM

START   EQU     $               ;START OF RELOCATED CODE
OFFSET  EQU     DEST-START      ;PROGRAM OFFSET AMOUNT

GETIT   EQU     $+OFFSET        ;PROGRAM START IN HI MEMORY
        LXI     H,BUFF          ;INITIALIZE BUFFER POINTER
GETLP   EQU     $+OFFSET        ;MAIN PROGRAM LOOP
        IN      MSTAT           ;GET MODEM STATUS
        ANI     RXRDY           ;DATA AVAILABLE ?
        JNZ     RXDRDY          ;YES, THEN JUMP            *
        CALL    CONST           ;NO, CHECK KEYBOARD
        ORA     A               ;ANYTHING TYPED ?
        JZ      GETLP           ;NO, THEN LOOP FOREVER
        CALL    CONIN           ;YES, GET IT
        CPI     CAPT            ;CTL-Y ?
        JZ      TOGCAPT         ;YES, TOGGLE CAPTURE FLAG
        CPI     EXIT            ;CTL-E ?
        JZ      ENDIT1          ;YES, WE'RE DONE FOR NOW
        MOV     C,A             ;NO, MOVE CHARACTER TO C
        CALL    SENDIT          ;SEND THE CHARACTER
        JMP     GETLP           ;LOOP FOREVER

SENDIT  EQU     $+OFFSET        ;SEND (C) TO MODEM
        IN      MSTAT           ;GET MODEM STATUS
        ANI     TXRDY           ;TX BUFFER EMPTY ?
        JZ      SENDIT          ;NO, LOOP UNTIL EMPTY      *  
        MOV     A,C             ;CHAR TO REG A
        OUT     MDATA           ;SEND TO MODEM
        RET

RXDRDY  EQU     $+OFFSET        ;RX DATA IS AVAILABLE
        IN      MDATA           ;GET MODEM CHARACTER
        ANI     7FH             ;CLEAR PARITY BIT
        MOV     C,A             ;PUT IN REG C
        LDA     CAPTFG          ;GET CAPTURE FLAG
        ORA     A               ;WANT TO SAVE IT ?
        JZ      NOSAVE          ;NO, THEN DON'T SAVE
        MOV     M,C             ;YES, PUT CHAR IN MEMORY
        INX     H               ;INCREMENT POINTER
        MOV     A,H             ;CHECK FOR TOO FAR
        CPI     DEST SHR 8      ;CAN'T SAVE THIS MUCH
        JZ      ENDIT           ;EXIT IF BUFFER IS FULL

       ;Insert "JMP  GETLP" here if you miss characters
       ;due to the delay caused by your CONOUT routine.
       ;This should only be necessary if your console is
       ;not much faster than the incoming data rate.
       ;You'll have to figure out some way to determine
       ;when the data has been captured, however.
          
NOSAVE  EQU     $+OFFSET        ;NOT SAVING OR NOT FULL
        CALL    CONOUT          ;DISPLAY RECEIVED CHAR
        JMP     GETLP           ;AND LOOP SOME MORE

TOGCAPT EQU     $+OFFSET        ;TOGGLE CAPTURE FLAG
        LDA     CAPTFG          ;GET IT
        CMA                     ;COMPLEMENT IT
        STA     CAPTFG          ;RESTORE FLAG
        ORA     A               ;CAPTURE NOW ON ?
        JZ      GETLP           ;NO, BACK TO LOOPING
        MVI     C,BELL          ;YES, TELL USER CAPTURE
        CALL    CONOUT          ; HAS BEEN TOGGLED ON
        JMP     GETLP           ;BACK TO LOOPING

ENDIT   EQU     $+OFFSET        ;BUFFER FULL, GO TO CP/M
        MVI     C,'S'-40H       ;STOP OUTPUT IF POSSIBLE
        CALL    SENDIT          ; WITH A CTL-S
ENDIT1  EQU     $+OFFSET        ;ENTER HERE TO EXIT W/O ^S
        MVI     A,'Z'-40H       ;END OF FILE FLAG
        MOV     M,A             ;SAVE IN BUFFER
        MOV     A,H             ;GET NUM OF PAGES TO SAVE
        PUSH    PSW             ;SAVE ON STACK
        LXI     D,SAVE          ;POINT DE TO "SAVE" MESSAGE
        MVI     C,9             ;PRINT STRING FUNCTION
        CALL    BDOS            ;PRINT EXITING MESSAGE
        POP     PSW             ;RESTORE NUMBER OF PAGES
        MVI     C,'0'           ;INIT HUNDREDS DIGIT
HUND    EQU     $+OFFSET        ;LOOP HERE 'TIL < 100
        SUI     100             ;ANY HUNDREDS DIGITS?
        JC      TENS            ;NO, CHECK TENS
        INR     C               ;YES, BUMP HUNDREDS DIGIT
        JMP     HUND            ;ANY MORE HUNDREDS ?
TENS    EQU     $+OFFSET        ;NO MORE HUNDREDS
        ADI     100             ;PUT BACK 100
        PUSH    PSW             ;SAVE COUNT
        CALL    CONOUT          ;PRINT HUNDREDS DIGIT
        POP     PSW             ;RESTORE COUNT
        MVI     C,'0'           ;INIT TENS DIGIT
TEN1    EQU     $+OFFSET        ;LOOP HERE 'TIL < 10
        SUI     10              ;ANY TENS DIGITS?
        JC      ONES            ;NO, CHECK ONES
        INR     C               ;YES, BUMP TENS DIGIT
        JMP     TEN1            ;ANY MORE TENS?
ONES    EQU     $+OFFSET        ;NO MORE TENS
        ADI     10+'0'          ;PUT BACK 10, ADD ASCII BIAS
        PUSH    PSW             ;SAVE NUMBER
        CALL    CONOUT          ;PRINT TENS DIGIT
        POP     PSW             ;RESTORE ONES DIGIT
        MOV     C,A             ;PASS TO CONOUT IN REG C
       CALL    CONOUT          ;PRINT ONES DIGIT
        LHLD   SPSAVE          ;GET OLD STACK POINTER
        SPHL                   ;PUT IN SP
       RET                     ;BACK TO CP/M

CONST   EQU     $+OFFSET        ;PATCHED BY PROGRAM TO
PCONST  JMP     BASE+6H         ; YOUR BIOS CONST ADDRESS
CONIN   EQU     $+OFFSET        ;PATCHED BY PROGRAM TO
PCONIN  JMP     BASE+9H         ; YOUR BIOS CONIN ADDRESS
CONOUT  EQU     $+OFFSET        ;PATCHED BY PROGRAM TO
PCONOUT JMP     BASE+0CH        ; YOUR BIOS CONOUT ADDRESS
SAVE    EQU     $+OFFSET        ;EXITING MESSAGE
        DB      BELL,CR,LF,LF,'GETIT exiting, SAVE $'
CAPTFG  EQU     $+OFFSET        ;CAPTURE FLAG
        DB      0               ;00 = NO CAPTURE, DEFAULT

PEND    EQU     $               ;END OF RELOCATED PROGRAM

SPSAVE EQU     $+OFFSET        ;ORIG SP SAVED HERE
        DS     2               ;DON'T INCLUDE IN BLOCK MOVE

        END
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