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Add punched tape emulation support

This commit is contained in:
CrazyEttin 2022-08-14 12:54:37 +03:00
parent 5d92a33796
commit 268bfcb843
2 changed files with 62 additions and 10 deletions
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60
emulator.pas
View File

@ -2,7 +2,7 @@ program Emulator;
{$MODE OBJFPC}
uses Crt;
uses SysUtils, Crt;
const
IO = $ffff;
@ -14,7 +14,10 @@ var
Addr, IP, RP: word; //Address argument and instruction and return pointers
R: array [0 .. 3] of byte; //General-purpose registers
Mem: array [0 .. $ffef] of byte; //Memory
Prog{$ifdef printer}, Prn{$endif}: file of byte; //Program file and printer
Prog{$ifdef printer}, Prn{$endif}{$ifdef tape}, TapeIn, TapeOut{$endif}: file of byte; //Program file, line printer, and punched tape reader and keypunch
{$ifdef tape}
TapePos: integer; //Punched tape reader position pointer
{$endif}
Ch: ansichar; //Character for input and output
begin
@ -23,6 +26,9 @@ begin
Hlt := false;
IP := 0;
RP := $fff0;
{$ifdef tape}
TapePos := 0;
{$endif}
//Read a program file and check for errors
if ParamCount <> 1 then begin
@ -121,23 +127,42 @@ begin
else if Op = 9 then R [X] := R [X] xor R [Y]
//Load
else if Op = $a then begin
//Input
//Dumb terminal input
if Addr = IO then begin
Ch := ReadKey;
write (Ch);
write (Ch); //Local echo
R [X] := byte (Ch);
end
//Punched tape reader
{$ifdef tape}
else if Addr = $fffd then begin
assign (TapeIn, 'tapein');
try
reset (TapeIn);
seek (TapeIn, TapePos);
if eof (TapeIn) = false then begin
read (TapeIn, R [X]);
TapePos := TapePos + 1;
end
else R [X] := 0;
close (TapeIn);
except
R [X] := 0;
TapePos := 0;
end;
end
{$endif}
//Regular load
else R [X] := Mem [Addr];
end
//Store
else if Op = $b then begin
//Output
//Dumb terminal output
if Addr = IO then begin
Ch := ansichar (R [X]);
write (Ch);
end
//Printer
//Line printer
{$ifdef printer}
else if Addr = $fffe then begin
assign (Prn, '/dev/usb/lp0');
@ -149,6 +174,29 @@ begin
end;
end
{$endif}
//Punched tape keypunch
{$ifdef tape}
else if Addr = $fffd then begin
assign (TapeOut, 'tapeout');
if FileExists ('tapeout') = false then begin
try
rewrite (TapeOut);
write (TapeOut, R [X]);
close (TapeOut);
except
end;
end
else begin
try
reset (TapeOut);
seek (TapeOut, FileSize (TapeOut));
write (TapeOut, R [X]);
close (TapeOut);
except
end;
end;
end
{$endif}
//Regular store
else Mem [Addr] := R [X];
end

12
readme.md
View File

@ -91,10 +91,14 @@ this.
Arbitrary devices can be mapped to the other reserved addresses.
The emulator can be compiled in Linux with support for a line printer at
/dev/usb/lp0 with the argument -dprinter. The printer is mapped to
address FFFE in the emulator. If you wish to use a different setup you
have to modify the code yourself.
The emulator can be compiled with support for a line printer at
/dev/usb/lp0 with the argument -dprinter, and for an emulated punched
tape reader and keypunch at tapein and tapeout respectively with -dtape.
The printer is mapped to address FFFE in the emulator and the tape
reader and keypunch to FFFD. To reset the tape reader to the beginning
of a tape, for example to change the tape, read once with no file at
tapein. If you wish to use a different setup you have to modify the code
yourself.
Initial Program Loader
----------------------