%
% SYSTEM-IO.RED - System dependent IO routines for Dec-20 PSL
%
% Author: Eric Benson
% Symbolic Computation Group
% Computer Science Dept.
% University of Utah
% Date: 16 September 1981
% Copyright (c) 1981 University of Utah
%
global '(IN!* OUT!*);
LoadTime <<
IN!* := 0;
OUT!* := 1;
>>;
fluid '(StdIN!* StdOUT!* ErrOUT!* !*Echo);
LoadTime <<
StdIN!* := 0;
StdOUT!* := 1;
ErrOUT!* := 1;
>>;
CompileTime flag('(RDTTY FindFreeChannel Dec20Open ContOpenError ClearIO1),
'InternalFunction);
on SysLisp;
external WArray JFNOfChannel, ReadFunction, WriteFunction, CLoseFunction;
if_system(Tops20,
lap '((!*entry Dec20ReadChar expr 1)
(!*MOVE (MEMORY (reg 1) (WConst JFNOfChannel)) (reg 1))
Loop % get JFN for channel
(bin) % read a character
(erjmp CheckEOF) % check for end-of-file on error
(!*JUMPEQ (Label Loop) (reg 2) (WConst 0))% try again if it's null char
(!*JUMPEQ (Label Loop) (reg 2) (WConst 8#15))% or carriage return
(!*MOVE (reg 2) (reg 1)) % move char to reg 1
(camn (reg nil) (fluid !*ECHO)) % is echo on?
(!*EXIT 0) % no, just return char
(!*PUSH (reg 1)) % yes, save char
(!*CALL WriteChar) % and write it
(!*POP (reg 1)) % restore it
(!*EXIT 0) % and return
CheckEOF
(gtsts) % check file status
(tlnn (reg 2) 2#000000001000000000) % gs%eof
(!*JUMP (Label ReadError))
(!*MOVE (WConst 26) (reg 1)) % return EOF char
(!*EXIT 0)
ReadError
(!*MOVE (QUOTE "Attempt to read from file failed") (reg 1))
(!*JCALL IoError)
));
if_system(Tenex,
lap '((!*entry Dec20ReadChar expr 1)
(!*MOVE (MEMORY (reg 1) (WConst JFNOfChannel)) (reg 1))
Loop % get JFN for channel
(bin) % read a character
(erjmp CheckEOF) % check for end-of-file on error
(!*JUMPEQ (Label Loop) (reg 2) (WConst 0))% try again if it's null char
(!*JUMPEQ (Label Loop) (reg 2) (WConst 8#15))% or carriage return
(cain (reg 2) (WConst 8#37)) % TENEX EOL
(!*MOVE (WConst 8#12) (reg 2)) % replace it with a linefeed
(!*MOVE (reg 2) (reg 1)) % move char to reg 1
(camn (reg nil) (fluid !*ECHO)) % is echo on?
(!*EXIT 0) % no, just return char
(!*PUSH (reg 1)) % yes, save char
(!*CALL WriteChar) % and write it
(!*POP (reg 1)) % restore it
(!*EXIT 0) % and return
CheckEOF
(gtsts) % check file status
(tlnn (reg 2) 2#000000001000000000) % gs%eof
(!*JUMP (Label ReadError))
(!*MOVE (WConst 26) (reg 1)) % return EOF char
(!*EXIT 0)
ReadError
(!*MOVE (QUOTE "Attempt to read from file failed") (reg 1))
(!*JCALL IoError)
));
lap '((!*entry Dec20WriteChar expr 2)
(!*MOVE (MEMORY (reg 1) (WConst JFNOfChannel)) (reg 1))
% get JFN for channel
(!*JUMPEQ (Label CRLF) (reg 2) (WConst 8#12)) % if LF, echo CRLF
(bout) % no, just echo char
(!*EXIT 0) % return
CRLF
(!*MOVE (WConst 8#15) (reg 2)) % write carriage-return
(bout)
(!*MOVE (WConst 8#12) (reg 2)) % write linefeed
(bout)
(!*EXIT 0) % return
);
internal WConst MaxTerminalBuffer = 200;
internal WVar NextTerminalChar = 1;
internal WString TerminalInputBuffer[MaxTerminalBuffer];
lap '((!*entry ClearIO1 expr 0)
%
% ^C from RDTTY and restart causes trouble, but we don't want a full RESET
% (don't want to close files or kill forks), so we'll just do the
% part of RESET that we want, for terminal input
%
(!*MOVE (WConst 8#100) (reg 1)) % .priin
(rfmod)
(tro 2 2#001111100001000000) % tt%wak + tt%eco + .ttasi, like RESET
(sfmod)
(!*EXIT 0)
);
syslsp procedure ClearIO();
<< ClearIO1();
TerminalInputBuffer[0] := -1;
NextTerminalChar := 0;
LispVar IN!* := LispVar STDIN!*;
LispVar OUT!* := LispVar STDOUT!* >>;
if_system(Tops20,
lap '((!*entry RDTTY expr 3)
(dmove (reg t1) (reg 1))
(!*MOVE (WConst 8#101) (reg 1)) % .priou
(rfmod) % read mode word
(tlze (reg 2) 2#100000000000000000) % if tt%osp is 0, then skip
(sfmod) % otherwise turn on output
(dmove (reg 1) (reg t1))
(!*MOVE (reg 2) (reg 4)) % save original count in r4
(!*WPLUS2 (reg 1) (WConst 1)) % make input buffer into byte pointer
(hrli (reg 1) 8#440700)
(!*WPLUS2 (reg 3) (WConst 1)) % make prompt string into byte pointer
(hrli (reg 3) 8#440700)
(!*MOVE (reg 1) (reg 5)) % print it once
(!*MOVE (reg 3) (reg 1))
(psout)
(!*MOVE (reg 5) (reg 1))
(hrli (reg 2) 2#000110000000000000) % rd%bel + rd%crf
(jsys 8#523) % RDTTY
(!*JUMP (Label CantRDTTY))
(!*MOVE (reg 4) (reg 1)) % move original count to r1
(hrrzs (reg 2)) % clear flag bits in r2
(!*WDIFFERENCE (reg 1) (reg 2)) % return # chars read, not # available
(!*EXIT 0)
CantRDTTY
(!*MOVE (QUOTE "Can't read from terminal") (reg 1))
(!*JCALL IOError)
));
if_system(Tenex,
lap '((!*entry RDTTY expr 3)
(move (reg t1) (reg 1))
(move (reg t2) (reg 2))
(!*MOVE (WConst 8#101) (reg 1)) % .priou
(rfmod) % read mode word
(tlze (reg 2) 2#100000000000000000) % if tt%osp is 0, then skip
(sfmod) % otherwise turn on output
(move (reg 1) (reg t1))
(move (reg 2) (reg t2))
(!*MOVE (reg 2) (reg 4)) % save original count in r4
(!*WPLUS2 (reg 1) (WConst 1)) % make input buffer into byte pointer
(hrli (reg 1) 8#440700)
(!*WPLUS2 (reg 3) (WConst 1)) % make prompt string into byte pointer
(hrli (reg 3) 8#440700)
(!*MOVE (reg 1) (reg 5)) % print it once
(!*MOVE (reg 3) (reg 1))
(psout)
(!*MOVE (reg 5) (reg 1))
% (hrli (reg 2) 2#000110000000000000) % rd%bel + rd%crf
% (jsys 8#523) % RDTTY
% (!*JUMP (Label CantRDTTY))
(!*MOVE (WConst MaxTerminalBuffer) (reg 2)) % # of chars
(setz 3 0) % clear 3
(jsys 8#611) % PSTIN, IMSSS JSYS
(!*MOVE (WConst 8#12) (reg 3)) % put linefeed at end of buffer
(dpb (reg 3) (reg 1)) % 1 points to end of what's been read
(!*MOVE (reg 4) (reg 1)) % move original count to r1
(hrrzs (reg 2)) % clear flag bits in r2
(!*WDIFFERENCE (reg 1) (reg 2)) % return # chars read, not # available
(!*EXIT 0)
));
syslsp procedure TerminalInputHandler Chn;
begin scalar Ch;
while NextTerminalChar >= StrLen TerminalInputBuffer do
<< NextTerminalChar := 0;
TerminalInputBuffer[0] := RDTTY(TerminalInputBuffer,
MaxTerminalBuffer,
if StringP LispVar PromptString!*
then LispVar PromptString!*
else ">") >>;
Ch := StrByt(TerminalInputBuffer, NextTerminalChar);
NextTerminalChar := NextTerminalChar + 1;
return Ch;
end;
syslsp procedure FindFreeChannel();
begin scalar Chn;
Chn := 0;
while JfnOfChannel[Chn] neq 0 do
<< if Chn >= MaxChannels then IOError("No free channels left");
Chn := Chn + 1 >>;
return Chn;
end;
syslsp procedure SystemMarkAsClosedChannel FileDes;
JFNOfChannel[IntInf FileDes] := 0;
lap '((!*entry Dec20CloseChannel expr 1)
(!*MOVE (reg 1) (reg 2)) % save in case of error
(!*MOVE (MEMORY (reg 1) (WConst JFNOfChannel)) (reg 1))
(closf)
(!*JUMP (Label CloseError))
(!*EXIT 0)
CloseError
(!*MOVE (QUOTE "Channel could not be closed") (reg 1))
(!*JCALL ChannelError)
);
syslsp procedure SystemOpenFileSpecial FileName;
<< JFNOfChannel[FileName := FindFreeChannel()] := -1;
FileName >>;
syslsp procedure SystemOpenFileForInput FileName;
begin scalar Chn, JFN;
Chn := FindFreeChannel();
JFN := Dec20Open(FileName,
% gj%old gj%sht
2#001000000000000001000000000000000000,
% 7*of%bsz of%rd
2#000111000000000000010000000000000000);
if JFN eq 0 then return ContOpenError(FileName, 'INPUT);
JFNOfChannel[Chn] := JFN;
ReadFunction[Chn] := 'Dec20ReadChar;
CloseFunction[Chn] := 'Dec20CloseChannel;
return Chn;
end;
syslsp procedure SystemOpenFileForOutput FileName;
begin scalar Chn, JFN;
Chn := FindFreeChannel();
JFN := Dec20Open(FileName,
% gj%fou gj%new gj%sht
2#110000000000000001000000000000000000,
% 7*of%bsz of%wr
2#000111000000000000001000000000000000);
if JFN eq 0 then return ContOpenError(FileName, 'OUTPUT);
JFNOfChannel[Chn] := JFN;
WriteFunction[Chn] := 'Dec20WriteChar;
CloseFunction[Chn] := 'Dec20CloseChannel;
return Chn;
end;
lap '((!*entry Dec20Open expr 3)
%
% Dec20Open(Filename string, GTJFN bits, OPENF bits)
%
(!*WPLUS2 (reg 1) (WConst 1)) % increment r1 to point to characters
(hrli (reg 1) 8#440700) % turn r1 into a byte pointer
(!*MOVE (reg 1) (reg 4)) % save filename string in r4
(!*MOVE (reg 2) (reg 1)) % GTJFN flag bits in r1
(!*MOVE (reg 4) (reg 2)) % string in r2
(gtjfn)
(!*JUMP (Label CantOpen))
(!*MOVE (reg 3) (reg 2)) % OPENF bits in r2, JFN in r1
(openf)
CantOpen
(!*MOVE (WConst 0) (reg 1)) % return 0 on error
(!*EXIT 0) % else return the JFN
);
off SysLisp;
lisp procedure ContOpenError(FileName, AccessMode);
ContinuableError(99,
BldMsg("`%s' cannot be open for %w",
FileName, AccessMode),
list('OPEN, MkSTR FileName, MkQuote AccessMode));
END;