Internet Info 1994 March/Internet Info CD-ROM (Walnut Creek) (March 1994).iso/networking/terms/kermit/a/cpxsb.asm

Assembly Source File | 1991-04-22 | 14.4 KB | 697 lines

IF NOT lasm
.printx * CPXSB.ASM *
ENDIF    ;NOT lasm
;       KERMIT - (Celtic for "FREE")
;
;       This is the CP/M-80 implementation of the Columbia University
;       KERMIT file transfer protocol.
;
;       Version 4.0
;
;       Copyright June 1981,1982,1983,1984,1985
;       Columbia University
;
; Originally written by Bill Catchings of the Columbia University Center for
; Computing Activities, 612 W. 115th St., New York, NY 10025.
;
; Contributions by Frank da Cruz, Daphne Tzoar, Bernie Eiben,
; Bruce Tanner, Nick Bush, Greg Small, Kimmo Laaksonen, Jeff Damens, and many
; others.
;
;    This file created 16 July, 1987 by OBSchou from code submitted
;    by William Rose for the Micromint SB180 systems (as featured in
;    BYTE magazine, 1986).  This file has been modified to fit in with
;    Kermit-80 V4.08 etc.  His file KERSYS.ASM is a stripped down version
;    of CPXSYS.ASM (formerly CP4SYS.ASM).
;
; revision history:
; KERSYS.ASM - version 0.8 dated 13 Jul 87.
;
; Cutdown CP4SYS.ASM for SB-180/Ampro 230.
;
;
; While this is a single CPU version (to ease editing) the assembler
; conditionals have been kept to identify machine specific code.
;
; Note that the baud setting routine also sets parity, but this does not
; change the parity given by Kermit's 'stat' command.  I assume that the
; main body of the program does its own parity check.
;
; Revision history (last entry first)
;
; edit 2, 22 July by OBSchou to massage file to fit with CPXCOM.ASM.
;
; edit 1, 15 July, 1987 by OBSchou for William Rose who submitted
;    the code for Kermit-80 V 4.05.  Modified code as appropriate
;    for 4.08 compatability.
;

delfac    EQU    150    ; Delay factor in SB-180 input loop - a fudge

;
; Keep module name, edit number, and last revision date in memory.
;
;sysedt:    db    'KERSYS.ASM (03) 12-FEB-87 $'    ; last SB-180 revision
;sysedt:    db    'KERSYS.ASM (04) 12-APR-87 $'    ; Telecom Merlin added
;sysedt:    db    'KERSYS.ASM (5)  9-May-87 $'    ; Minor tidying
;sysedt:    db    'KERSYS.ASM (6A) 17-Jun-87 $'    ; BT Merlin M2215 only
;sysedt:    db    'KERSYS.ASM (7)  19-Jun-87 $'    ; SB-180 only
;sysedt:    db    'KERSYS.ASM (8)  13-Jul-87 $'    ; 6/9 MHz version
family:    db    'CPXSB.ASM (2)  22-Jul-87$'    ; First entry for V4.08/9

;
; Assembly time message to let me know I'm building the right version.
;

IF sb180
.printx * Assembling Kermit-80 for Micromint SB-180 *
ENDIF


IF sb180
mnctrla    EQU    000H    ;Modem control port - CNTLA0
mnctrlb    EQU    002H    ;Modem control port - CNTLB0
mnstat    EQU    004H    ;Modem status port - STAT0
mntxdat    EQU    006H    ;Modem output port - TDR0
mnrddat    EQU    008H    ;Modem input port - RDR0
output    EQU    002H    ;Transmit data register empty mask - TDRE
input    EQU    080H    ;Receive data register full mask - RDRF
z80    EQU    TRUE    ;This one's an HD64180, but Z80 will do
ENDIF


sysxin:        ; continuation of system initialisation from sysinit

IF sb180
    lxi    h, porbuf    ; park the original settings
    db    0EDh, 038h, mnctrla    ; HD64180 code IN0 g,(m)
    mov    m, a
    inx    h
    db    0EDh, 038h, mnctrlb
    mov    m, a
    inx    h
    db    0EDh, 038h, mnstat
    mov    m, a
ENDIF
                ; re-initialise for KERMIT
IF sb6
    mvi    h, 08h        ; 0000$1001 - 9600 baud, (even) parity
    mvi    l, 08h        ; 'speed' is two bytes
ENDIF

IF sb9
    mvi    h, 21h        ; 0010$0001 - 9600 baud, (even) parity
    mvi    l, 21h        ; 'speed' is two bytes
ENDIF

IF sb180
    shld    speed
    lxi    h, parind
    mvi    m, 8        ; index for 8 bits, no parity, 2 stop
    call    setpor
ENDIF

    ret

porbuf:    ds    3        ; original port settings

;
;    system-dependent KERMIT termination processing
;    If we've changed anything, this is our last chance to put it back.
;
sysexit:

IF sb180
    lxi    h, porbuf
    mov    a, m        ; output parity
    db    0EDh, 039h, mnctrla    ; HD64180 code OUT0 (m),g
    inx    h
    mov    a, m        ; output baud rate
    db    0EDh, 039h, mnctrlb
    inx    h
    mov    a, m        ; output to clear error flags
    db    0EDh, 039h, mnstat
                ; read twice to reset DCD0 ?
    db    0EDh, 038h, mnstat
    db    0EDh, 038h, mnstat
ENDIF

    ret

;
;    system-dependent processing for start of CONNECT command
;
syscon:
    ret

conmsg:        ; Messages printed when entering transparent (CONNECT) mode:

    db    '$'

;
;    syscls - system-dependent close routine
;    called when exiting transparent session.
;
syscls:
    ret

;
;    sysinh - help for system-dependent special functions.
;    called in response to <escape>?, after listing all the
;    system-independent escape sequences.
;
sysinh:

IF sb180
    lxi    d, inhlps
    call    prtstr
ENDIF

    ret

; Additional, system-dependent help for transparent mode
; (two-character escape sequences)
inhlps:

IF sb180
    db    cr, lf, 'V  Cycle port parameters'
ENDIF

    db    '$'            ; string terminator

;
;    sysint - system dependent special functions
;    called when transparent escape character has been typed;
;    the second character of the sequence is in A (and in B).
;    returns:
;    non-skip: sequence has been processed
;    skip:    seqence was not recognized
;
sysint:
;    ani    137O        ; convert lower case to upper, for testing...
                ; does this work?
IF sb180
    cpi    'V'        ; cycle port ?
    jz pcycl
    cpi    'v'
    jz pcycl
ENDIF

    jmp    rskp        ; take skip return - command not recognised

; Actual commands

IF sb180
pcycl:
    lxi    h, parind    ; increment parval, modulo 12
    mov    a, m
    adi    1
    cpi    13
    jnz    pcy1
    mvi    a, 1
pcy1:    mov    m, a        ; update the storage
                ; get index of name in parstr
    ora    a        ; clear flags
    dcr    a
    rlc
    rlc
    mov    c, a
    mvi    b, 0
    lxi    h, parstr
    inx    h
    dad    b
    push    h
    lxi    d, cgmsg1
    call    prtstr
    pop    d
    call    prtstr
    lxi    d, cgmsg2
    call    prtstr
    call    setpor        ; reset the port

    ret

cgmsg1:    db    '<$'
cgmsg2: db    '>$'
ENDIF

    ret

;
;    Delay routine.  Called with time (hundredths of seconds) in A.
;    The inner loop delays 1001 T-states, assuming no wait states are
;    inserted; this is repeated CPUSPD times, for a total delay of just
;    over 0.01 second. (CPUSPD should be set to the system clock rate,
;    in units of 100KHz: for an unmodified Kaypro II, that's 25 for
;    2.5 MHz.  Some enterprising soul could determine whether or not the
;    Kaypro actually inserts a wait state on instruction fetch (a common
;    practice); if so, the magic number at delay2 needs to be decreased.
;    (We also neglect to consider time spent at interrupt level).
;
;    called by: sendbr
;    destroys BC
;
;delay:    mvi    c,cpuspd    ; Number of times to wait 1000 T-states to
;                ;  make .01 second delay
;delay2:    mvi    b,70        ; Number of times to execute inner loop to
;                ;  make 1000 T-state delay
;delay3:    dcr    b        ; 4 T-states (* 70 * cpuspd)
;    jnz    delay3        ; 10 T-states (* 70 * cpuspd)
;    dcr    c        ; 4 T-states (* cpuspd)
;    jnz    delay2        ; 10 T-states (* cpuspd)
;                ; total delay: ((14 * 70) + 14) * cpuspd
;                ;  = 1001 * cpuspd
;    dcr    a        ; 4 T-states
;    jnz    delay        ; 10 T-states
;
;    ret            ; grand total: ((1001 * cpuspd) + 14) * a

;
;    sysflt - system-dependent filter
;    called with character in E.
;    if this character should not be printed, return with A = zero.
;    preserves bc, de, hl.
;    note: <xon>,<xoff>,<del>, and <nul> are always discarded.
;
sysflt:
    mov    a,e        ; get character for testing
    ret

;
;    mdmflt - modem filter
;    called with character to be sent to printer in E
;    with parity set as appropriate.
;    return with accumulator = 0 do do nothing,
;                <> 0 to send char in E.
mdmflt:
    mov    a,e        ; get character to test
    ret

;
;    prtflt - printer filter
;    called with character to be sent to printer in E
;    returns with a = 0 to do nothing
;             a <> 0 to print it.
;
;    this routine for those printer that automatically insert
;    a lf on cr, or cr for lf.  Should this be shifted to
;    the system indep. stuff, in say 4.06?
;
prtflt:
    mov    a,e        ; get character to test

IF FALSE            ; strip out lf from printer stream
    ani    7fh        ; make sure it is parity less
    cpi    lf        ; is it a line feed?
    rnz            ; no, print it
;    xra    a        ; yes, don't.

ENDIF

    ret

;
; system-dependent processing for BYE command.
;
sysbye:
    ret

;
;    This is the system-dependent command to change the baud rate.
;    DE contains the two-byte value from the baud rate table; both
;    bytes of this value are also stored in 'speed'.
;
sysspd:

IF sb180
    lxi    d, prtmsg    ; ask for variables
    call    prtstr

    lxi    d, tbuf        ; get suitable string
    mvi    c, 10
    call    bdos

    lxi    h, tbuf1
    mov    a, m
    ora    a
    jz    setpor        ; leave unchanged if string zero length

    cpi    3        ; check given length
    jnz    spd1        ; error - wrong length
    inx    h
    inx    h
    mov    a, m
    ani    137O        ; convert parity code to upper case
    mov    m, a

    lxi    d, tbuf1    ; get index of given parameter
    lxi    h, parstr
    call    sposn
    ora    a
    jnz    spd2        ; or fall through if error
spd1:    lxi    d, invmsg    ; invalid input - try again
    call    prtstr
    jmp    sysspd

spd2:    adi    3        ; get index to parval table
    rrc            ; by dividing by 4
    rrc
    ani    15        ; mask out high bits
    lxi    h, parind
    mov    m, a        ; and store it
    call    setpor        ; set up port iaw index and speed bytes

    ret

prtmsg:    db    cr,lf,'Enter bit/char, parity, and stop bits required.'
    db    cr,lf,'(Bit 7/8   Parity N/O/E   Stop 1/2  - CR same) : $'
invmsg: db    cr,lf,'Invalid parameters$'

parind:    db    8        ; default <8N2> index
parstr:    db    48,'7N1$7N2$7O1$7O2$7E1$7E2$'
    db       '8N1$8N2$8O1$8O2$8E1$8E2$'
parval:    db    0,1,16+2,16+3,2,3
    db    4,5,16+6,16+7,6,7
tbuf    db    6
tbuf1    db    3,'8N2','$$$$'

;
; Set up the port using the table index in parind and the speed byte
;
setpor:
    lxi    h, parind
    mov    a, m
    dcr    a
    lxi    h, parval    ; table base
    mvi    b, 0
    mov    c, a
    dad    b        ; HL points at parameter value
    mov    a, m
    mov    b, a        ; park parval

    ani    16        ; the parity switch bit
    lxi    h, speed
    add    m        ; this is now the baud rate byte
    mov    c, a        ; park it

    mov    a, b        ; sort out the parameter byte
    ani    7        ; b/p/s only wanted
    adi    96        ; RE, TE enable
    db    0EDh,039h,mnctrla    ; output parity etc.
    mov    a, c
    db    0EDh,039h,mnctrlb    ; output baud rate
    mvi    a, 0
    db    0EDh,039h,mnstat    ; clear status
    db    0EDh,038h,mnstat    ; read twice to reset DCD0
    db    0EDh,038h,mnstat
    ret

;
; Find substring position - Leventhal page 293, modified
; enter with subtring in DE and string in HL
; returns index in A or 0 for failure
;
sposn:
    mov    a, m        ; exit if either string length zero
    ora     a
    jz    notfnd
    sta    slen
    mov    b, a
    inx    h
    shld    string
    xchg
    mov    a, m
    ora     a
    jz    notfnd
    sta    sublen
    mov    c, a
    inx    h
    shld    substg
    mov    a, b

; no of searches = stringlen - substrlen + 1
; if substr longer than string quit immediately

    sub    c
    jc    notfnd
    inr    a
    mov    c, a
    xra    a
    sta    index

; search until remaining string shorter than substring

slp1:    lxi    h, index
    inr    m
    lda    sublen
    mov    b, a
    lhld    substg
    xchg
    lhld    string

; try to match substring starting at index

cmplp:    ldax    d
    cmp    m
    jnz    slp2
    dcr    b
    jz    found
    inx    h
    inx    d
    jmp    cmplp

; arrive here if match fails

slp2:    dcr    c
    jz    notfnd
    lhld    string
    inx    h
    shld    string
    jmp    slp1

; found, return index

found:    lda    index
    ret

; not found, return zero

notfnd:    sub    a
    ret

string:    ds    2
substg:    ds    2
slen:    ds    1
sublen:    ds    1
index:    ds    1
ENDIF

    ret

;
;    Speed tables
; (Note that speed tables MUST be in alphabetical order for later
; lookup procedures, and must begin with a value showing the total
; number of entries.  The speed help tables are just for us poor
; humans.
;
;     db    string length, string, divisor (2 bytes or 1 word, ab)
;        the data byte a is return in A and E, and b in D
;        only byte 'a' is the key for the table

IF sb6
spdtbl:    db    9            ; 9 entries
    db    04h,'1200$',    0Bh,0Bh
    db    03h,'150$',    0Eh,0Eh
    db    05h,'19200$',    01h,01h
    db    04h,'2400$',    0Ah,0Ah
    db    03h,'300$',    0Dh,0Dh
    db    05h,'38400$',    00h,00h
    db    04h,'4800$',    09h,09h
    db    03h,'600$',    0Ch,0Ch
    db    04h,'9600$',    08h,08h

sphtbl: db    cr,lf
    db '   150  300  600  1200  2400  4800  9600  19200  38400$'
ENDIF

IF sb9
spdtbl:    db    7            ; 7 entries
    db    04h,'1200$',    24h,24h
    db    05h,'19200$',    20h,20h
    db    04h,'2400$',    23h,23h
    db    03h,'300$',    26h,26h
    db    04h,'4800$',    22h,22h
    db    03h,'600$',    25h,25h
    db    04h,'9600$',    21h,21h

sphtbl: db    cr,lf
    db '   300  600  1200  2400  4800  9600  19200$'
ENDIF


;
;    This is the system-dependent SET PORT command.
;    HL contains the argument from the command table.
;
sysprt:
    ret

IF sb180
prttbl EQU    0        ; SET PORT is not supported
prhtbl EQU    0
ENDIF

;
;    selmdm - select modem port
;    selcon - select console port
;    selmdm is called before using inpmdm or outmdm;
;    selcon is called before using inpcon or outcon.
;    For iobyt systems, diddle the I/O byte to select console or comm port;
;    For the rest, does nothing.
;    preserves bc, de, hl.
;
selmdm:
    ret

selcon:
    ret

;
;    Get character from console, or return zero.
;    result is returned in A.  destroys bc, de, hl.
;
inpcon:
    mvi    c,dconio    ;Direct console I/O BDOS call.
    mvi    e,0FFH        ;Input.
    call    BDOS

    ret

;
;    Output character in E to the console.
;    destroys bc, de, hl
;
outcon:
    mvi    c,dconio    ;Console output bdos call.
    call    bdos        ;Output the char to the console.

    ret

;
;    outmdm - output a char from E to the modem.
;        the parity bit has been set as necessary.
;    returns nonskip; bc, de, hl preserved.
;
outmdm:

IF sb180
    db    0EDh,038h,mnstat
    ani    output        ; check status
    jz    outmdm        ; wait until port is available
    mov    a, e
    db    0EDh,039h,mntxdat    ; transmit
ENDIF

    ret

;
;    get character from modem; return zero if none available.
;    for IOBYT systems, the modem port has already been selected.
;    destroys bc, de, hl.
;
inpmdm:

IF sb180
    lxi    h, delfac    ; loops to give delay
inpm1:    db    0EDh,038h,mnstat
    ani    input        ; check status
    jz    inpm2
    db    0EDh,038h,mnrddat    ; get a byte
    ret

inpm2:    dcx    h        ; no data
    mov    h, a
    ora    l
    jnz    inpm1        ; still tries left
    ret            ; with zero in A
ENDIF

    ret

;
;    flsmdm - flush comm line.
;    Modem is selected.
;    Currently, just gets characters until none are available.
;
flsmdm:
    call    inpmdm        ; Try to get a character
    ora    a        ; Got one?
    jnz    flsmdm        ; If so, try for another
    ret            ; Receiver is drained.  Return.

;

;
;       lptstat - get the printer status. Return a=0 if ok, or 0ffh if not.
lptstat:
IF iobyte       ;[33]
        call    bprtst          ; get status
ENDIF   ;iobyte[33]
IF NOT iobyte   ;[33]
        xra     a               ; assume it is ok.. this may not be necessary
ENDIF   ;iobyte [33]
        ret
;
;    outlpt - output character in E to printer
;    console is selected.
;    preserves de.
;
outlpt:
    push    d        ; save DE in either case
    call    prtflt        ; go through printer filter [30]
    ana    a        ; if A = 0 do nothing,
    jz    outlp1        ; if a=0 do nothing

outlp1:    pop    d        ; restore saved register pair
    ret

; delchr - make delete look like a backspace.  Unless delete is a printing
;    character, we just need to print a backspace. (we'll output clrspc
;    afterwards)
delchr:

    mvi    e,bs        ;get a backspace
    jmp    outcon

; erase the character at the current cursor position
clrspc:    mvi    e,' '
    call    outcon
    mvi    e,bs        ;get a backspace
    jmp    outcon

; erase the current line
clrlin:    lxi    d,eralin
    jmp    prtstr

; erase the whole screen, and go home. preserves b (but not c)
clrtop:    lxi    d,erascr
    jmp    prtstr

IF sb180
sysver:    db    'MicroMint SB 180 '
ENDIF

IF sb6
    db    ' (6 MHz)'
ENDIF

IF sb9
    db    ' (9 MHz)'
ENDIF
    db    '$'

IF lasm
LINK CPXVDU.ASM        ; get terminal defs etc
ENDIF    ;lasm