updated README about serial card configuration

Changed serial stop bits default to 1 (from 2); added option switch to select 1 or 2.

.gitignore

@@ -0,0 +1,7 @@
+# ignore these files
+*~
+*.o
+*.exe
+*.dsk
+*.DSK
+# the end

README.md

@@ -1,14 +1,38 @@
-<B>tu58em</B> is a software emulation of a DECtapeII TU-58 block addressable cartridge tape drive. It requires only a standard Windows PC as a host with an RS232 serial port to connect to the target system.
+<B>tu58em</B> is a software emulation of a DECtapeII TU-58 block addressable cartridge tape drive. It requires only a standard Windows PC as a host with a (real or USB) RS232 serial comm port to connect to the target system.
 
-<B>tu58em</B> was originally based on the 1984 Dan Ts'o tu58 program, but has been almost completely rewritten to make it compile error free, improve the program flow, and add new functionality. It has been compiled within the CYGWIN environment, and will run either within a CYGWIN window or an MSDOS command window with the associated cygwin1.dll helper file. <B>tu58em</B> has been tested under Win2K, WinXPsp3, and Win7sp1. <B>tu58em</B> has compiled error free under Linux (Ubuntu 12.02LTS) but has not yet been rigorously tested in that environment.
+<B>tu58em</B> was originally based on the 1984 Dan Ts'o tu58 program, but has been almost completely rewritten to make it compile error free, improve the program flow, and add new functionality. It has been compiled within the CYGWIN environment, and will run either within a CYGWIN window or an MSDOS command window with the associated cygwin1.dll helper file. <B>tu58em</B> has been tested under WinXPsp3, Win7sp1(64b), and Linux (Ubuntu 12.02LTS).
 
 Each emulated .dsk image file is exactly 256KB (512 blocks of 512 bytes) of data and is a byte-for-byte image of the data on a TU-58 cartridge tape. As currently configured <B>tu58em</B> will support up to 8 drives per controller as DD0: to DD7: (altho this is easily changed in the source). <B>tu58em</B> will support disk image files as large as the TU58 protocol allows (ie, 32MB, or 64K 512B blocks); however most standard DEC operating system drivers restrict TU58 drives to 256KB each. The DEC driver must be patched to allow for larger than 256KB disk images.
 
-<B>tu58em</B> has been tested using both native RS232 serial COM ports and serial ports emulated thru USB serial adapters.
+As of v1.4m Mark Blair's updates for VAX mode operation (for VAX-730 microcode boot support) and background mode are integrated.
 
-Note: <B>tu58em</B> is compiled using the CYGWIN serial interface library routines (ie, termios.h) and is the preferred version that should be used. <B>tu58ew</B> bypasses the CYGWIN serial interface layer and makes direct Windows serial comm routine calls. This version was done early on because of deficiencies in the CYGWIN serial library. However, the required features are now present so in reality <B>tu58ew</B> should be considered deprecated.
+As of v2.0a the serial support routines have been rewritten to, under Linux, use termios.h PARMRK mode to allow detecting BREAK inline within the rx byte stream, and respond correctly (ie, abort current command in process and return to init loop). PARMRK mode in CYGWIN termios appears not be be working correctly at all. Windows communication mode (-DWINCOMM) is preferred for CYGWIN, as BREAK is detected correctly. MACOS support of PARMRK mode is unknown. The makefile is setup to detect the operating system type and define the compilation options correctly.
 
-The latest version (as of 1.4m) integrates Mark Blair's updates for VAX mode operation (for VAX-730 microcode boot support) and background mode.
+The following configurations have been tested:
+```
+System      Mode             Port           Status
+----------  --------------   ------------   --------------------------------------
+Win/CYGWIN  WINCOMM          real comm      PASS, BREAK detected
+Win/CYGWIN  WINCOMM          USB ftdi       PASS, BREAK detected
+Win/CYGWIN  WINCOMM          USB prolific   conditional PASS, BREAK not detected
+----------  --------------   ------------   --------------------------------------
+Win/CYGWIN  termios          real comm      conditional PASS; BREAK not detected
+Win/CYGWIN  termios          USB ftdi       conditional PASS; BREAK not detected
+Win/CYGWIN  termios          USB prolific   conditional PASS; BREAK not detected
+----------  --------------   ------------   --------------------------------------
+Win/CYGWIN  termios+PARMRK   any            FAIL, does not work at all
+----------  --------------   ------------   --------------------------------------
+Linux       termios+PARMRK   real comm      PASS, BREAK detected
+Linux       termios+PARMRK   USB ftdi       PASS, BREAK detected
+Linux       termios+PARMRK   USB prolific   conditional PASS; BREAK not detected
+----------  --------------   ------------   --------------------------------------
+Note:
+(1) Win/CYGWIN = CYGWIN_NT-5.1 1.7.35(0.287/5/3) i686 Cygwin
+(2) Linux = Ubuntu 12.04.5 LTS (GNU/Linux 3.2.0-124-generic) x86_64 GNU/Linux
+```
+So it appears that the drivers for real comm ports handle BREAK correctly, as does the driver for the USB ftdi adapter, on both WinXP and Linux. The USB prolific adapter hardware and/or driver do not handle a BREAK, altho all data transfers operate correctly.
+
+Configuring your serial card in the PDP-11 requires it be setup as 8-N-1 (8b data, no parity, one stop) AND that the serial interface card (example, a DL11-W in a UNIBUS system) be setup at the standard address of 776500 thru 776506. Also make sure that the card is enabled to send BREAK as that is an integral part of the TU58 serial protocol.
 
 A cygwin folder with a precompiled 32b cygwin executable (tu58em.exe) is included for those without cygwin environment access. Under Windows, just open a standard CMD.EXE window, change to the cygwin folder, and run the <B>tu58em.exe</B> executable as a command line program.
 
@@ -18,7 +42,7 @@ If the emulator is run with no options, it prints a usage screen:
 E:\DEC> tu58em
 ERROR: no units were specified
 FATAL: illegal command line
-  tu58 tape emulator v1.4m
+  tu58 tape emulator v2.0a
   Usage: ./tu58em [-options] -[rwci] file1 ... -[rwci] file7
   Options: -V | --version            output version string
            -v | --verbose            enable verbose output to terminal
@@ -29,7 +53,8 @@ FATAL: illegal command line
            -b | --background         run in background mode, no console I/O except errors
            -t | --timing 1           add timing delays to spoof diagnostic into passing
            -T | --timing 2           add timing delays to mimic a real TU58
-           -s | --speed BAUD         set line speed [1200..3000000; default 9600]
+           -s | --speed BAUD         set line speed to BAUD; default 9600
+           -S | --stop BITS          set stop bits 1..2; default 1
            -p | --port PORT          set port to PORT [1..N or /dev/comN; default 1]
            -r | --read|rd FILENAME   readonly drive
            -w | --write FILENAME     read/write drive
@@ -51,10 +76,12 @@ Most of the switches should be pretty obvious:
 -b   run in background mode, no console I/O except errors
 -t   adds time delays to allow the emulator to pass the DEC ZTUUF0 TU-58 Performance Exerciser diagnostic
 -T   adds time delays to make the emulator nearly as slow as a real TU-58 (just for fun)
--s BAUD      sets the baud rate; the following rates are supported. the default will be 9600 if not set.
-                      3000000, 2500000, 2000000, 1500000, 1152000, 1000000, 921600, 576000, 500000,
-		      460800, 256000, 230400, 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200
+-s BAUD      sets the baud rate; the following rates may be supported. the default will be 9600 if not set.
+                  3000000, 2500000, 2000000, 1500000, 1152000, 1000000, 921600, 576000, 500000,
+                  460800, 230400, 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200
+             exact list of baud rate support is system dependent (especially for rates above 230400)
 -p PORT      sets the com port as a number (1,2,3,...) or if not numeric the full path (/dev/com1)
+-S STOP      sets the number of stop bits (1 or 2), default is 1
 -r FILENAME  set the next unit as a read only drive using file FILENAME
 -w FILENAME  set the next unit as a read/write drive using file FILENAME
 -c FILENAME  set the next unit as a read/write drive using file FILENAME, zero the file before use
@@ -69,10 +96,11 @@ E:\DEC> tu58em -p 3 -s 38400 -r boot.dsk -i rt11.dsk
 info: initialize RT-11 directory on 'rt11.dsk'
 info: unit 0 r    file 'boot.dsk'
 info: unit 1 rwci file 'rt11.dsk'
-info: serial port 3 at 38400 baud
-info: TU58 emulation start
+info: serial port 3 at 38400 baud 1 stop
+info: TU58 start
 info: R restart, S toggle send init, V toggle verbose, D toggle debug, Q quit
-info: emulator started
+info: TU58 emulator started
+info: <BREAK> seen
 info: <INIT><INIT> seen, sending <CONT>
 info: read     unit=0 sw=0x00 mod=0x00 blk=0x0000 cnt=0x0400
 info: read     unit=0 sw=0x00 mod=0x00 blk=0x0006 cnt=0x0400

common.h

@@ -2,7 +2,7 @@
 // tu58 - Emulate a TU58 over a serial line
 //
 // Original (C) 1984 Dan Ts'o <Rockefeller Univ. Dept. of Neurobiology>
-// Update   (C) 2005-2016 Donald N North <ak6dn_at_mindspring_dot_com>
+// Update   (C) 2005-2017 Donald N North <ak6dn_at_mindspring_dot_com>
 //
 // All rights reserved.
 //
@@ -80,10 +80,9 @@ typedef struct timespec timespec_t;
 #define FILERT11INIT	4	// file should be init'ed as RT11 structure
 #define FILEXXDPINIT	5	// file should be init'ed as XXDP structure
 
-#define DEV_NYI		-1	// not yet implemented
-#define DEV_OK		 0	// no error
-#define DEV_BREAK	 1	// BREAK on line
-#define DEV_ERROR	 2	// ERROR on line
+#define DEV_NORMAL	0	// normal data byte
+#define DEV_BREAK	1	// BREAK on line
+#define DEV_ERROR	2	// ERROR on byte
 
 
 
@@ -104,9 +103,8 @@ void devtxput (uint8_t);
 int32_t devtxwrite (uint8_t *, int32_t);
 void devrxinit (void);
 int32_t devrxavail (void);
-int32_t devrxerror (void);
-uint8_t devrxget (void);
-void devinit (char *, int32_t);
+uint8_t devrxget (uint8_t *);
+void devinit (char *, int32_t, int32_t);
 void devrestore (void);
 void coninit (void);
 void conrestore (void);

file.c

@@ -354,7 +354,7 @@ int32_t fileseek (int32_t unit,
 {
     if (fileunit(unit)) return -1;
 
-    if (block*size+offset > lseek(file[unit].fd, 0, SEEK_END)) return -2;
+    if (block*size+offset >= lseek(file[unit].fd, 0, SEEK_END)) return -2;
 
     if (lseek(file[unit].fd, block*size+offset, SEEK_SET) < 0) return -3;
 

main.c

@@ -2,7 +2,7 @@
 // tu58 - Emulate a TU58 over a serial line
 //
 // Original (C) 1984 Dan Ts'o <Rockefeller Univ. Dept. of Neurobiology>
-// Update   (C) 2005-2016 Donald N North <ak6dn_at_mindspring_dot_com>
+// Update   (C) 2005-2017 Donald N North <ak6dn_at_mindspring_dot_com>
 //
 // All rights reserved.
 //
@@ -73,6 +73,17 @@
 // v1.4m - 23 Feb 2016 - donorth - Added M. Blair's vax console timeout changes for '730
 //                               - Added M. Blair's background mode option (no status).
 // v1.4n - 06 Apr 2016 - donorth - Added capability for baud rates >230K, up to 3M
+// v1.4o - 09 Jan 2017 - donorth - Removed baud rate 256000, it is nonstandard for unix.
+//                                 Changed serial setup to use cfsetispeed()/cfsetospeed()
+//                                 Added capability for 1 or 2 stop bits; default is 1
+// v1.4p - 05 May 2017 - donorth - Updated serial baud rate table with #ifdef detection
+//                                 Update clock_gettime() for MAC OSX support
+// v1.4q - 16 May 2017 - donorth - Fixed error in fileseek() routine (should fail at EOF)
+// v2.0a - 19 May 2017 - donorth - Rewrite of serial.c to support PARMRK mode on linux
+//                                 so that BREAKs are handled correctly via setjmp/longjmp
+//                                 Update tu58drive.c to intercept rx byte read routine to
+//                                 detect input line BREAK and process as required.
+// v2.0b - 03 Apr 2018 - donorth - Change iflags from PARMRK|IGNPAR to PARMRK|INPCK
 //
 
 
@@ -80,13 +91,14 @@
 #include <getopt.h>
 
 
-static char copyright[] = "(C) 2005-2016 Don North <ak6dn" "@" "mindspring.com>, " \
+static char copyright[] = "(C) 2005-2017 Don North <ak6dn" "@" "mindspring.com>, " \
                           "(C) 1984 Dan Ts'o <Rockefeller University>";
 
-static char version[] = "tu58 tape emulator v1.4n";
+static char version[] = "tu58 tape emulator v2.0b";
 
 static char port[32] = "1"; // default port number (COM1, /dev/ttyS0)
 static long speed = 9600; // default line speed
+static long stop = 1; // default stop bits, 1 or 2
 
 uint8_t verbose = 0; // set nonzero to output more info
 uint8_t timing = 0; // set nonzero to add timing delays
@@ -152,7 +164,7 @@ void fatal (char *fmt, ...)
 // main program
 //
 int main (int argc,
-	  char **argv)
+	  char *argv[])
 {
     long i;
     long n = 0;
@@ -160,37 +172,39 @@ int main (int argc,
 
     // switch options
     int opt_index = 0;
-    char opt_short[] = "dvVmnxbTtp:s:r:w:c:i:z:";
+    char opt_short[] = "dvVmnxbTtp:s:r:w:c:i:z:S:";
     static struct option opt_long[] = {
-	{ "debug",	no_argument,       0, 'd' },
-	{ "verbose",	no_argument,       0, 'v' },
-	{ "version",	no_argument,       0, 'V' },
-	{ "mrsp",	no_argument,       0, 'm' },
-	{ "nosync",	no_argument,       0, 'n' },
-	{ "vax",	no_argument,       0, 'x' },
-	{ "background",	no_argument,       0, 'b' },
-	{ "timing",	required_argument, 0, -2  },
-	{ "port",	required_argument, 0, 'p' },
-	{ "baud",	required_argument, 0, 's' },
-	{ "speed",	required_argument, 0, 's' },
-	{ "rd",		required_argument, 0, 'r' },
-	{ "read",	required_argument, 0, 'r' },
-	{ "write",	required_argument, 0, 'w' },
-	{ "create",	required_argument, 0, 'c' },
-	{ "initrt11",	required_argument, 0, 'i' },
-	{ "initxxdp",	required_argument, 0, 'z' },
-	{  0,           no_argument,       0,  0  }
+	{ "debug",	no_argument,       NULL, 'd' },
+	{ "verbose",	no_argument,       NULL, 'v' },
+	{ "version",	no_argument,       NULL, 'V' },
+	{ "mrsp",	no_argument,       NULL, 'm' },
+	{ "nosync",	no_argument,       NULL, 'n' },
+	{ "vax",	no_argument,       NULL, 'x' },
+	{ "background",	no_argument,       NULL, 'b' },
+	{ "timing",	required_argument, NULL, -2  },
+	{ "port",	required_argument, NULL, 'p' },
+	{ "baud",	required_argument, NULL, 's' },
+	{ "speed",	required_argument, NULL, 's' },
+	{ "stop",	required_argument, NULL, 'S' },
+	{ "rd",		required_argument, NULL, 'r' },
+	{ "read",	required_argument, NULL, 'r' },
+	{ "write",	required_argument, NULL, 'w' },
+	{ "create",	required_argument, NULL, 'c' },
+	{ "initrt11",	required_argument, NULL, 'i' },
+	{ "initxxdp",	required_argument, NULL, 'z' },
+	{  NULL,        no_argument,       NULL,  0  }
     };
 
     // init file structures
     fileinit();
 
     // process command line options
-    while ((i = getopt_long(argc, argv, opt_short, opt_long, &opt_index)) != EOF) {
+    while ((i = getopt_long(argc, argv, opt_short, opt_long, &opt_index)) != -1) {
 	switch (i) {
 	case -2 :  timing = atoi(optarg); if (timing > 2) errors++; break;
 	case 'p':  strcpy(port, optarg);  break;
 	case 's':  speed = atoi(optarg);  break;
+	case 'S':  stop = atoi(optarg);  break;
 	case 'r':  fileopen(optarg, FILEREAD);  n++;  break;
 	case 'w':  fileopen(optarg, FILEWRITE);  n++;  break;
 	case 'c':  fileopen(optarg, FILECREATE);  n++;  break;
@@ -232,7 +246,8 @@ int main (int argc,
 	      "           -b | --background         run in background mode, no console I/O except errors\n" \
 	      "           -t | --timing 1           add timing delays to spoof diagnostic into passing\n" \
 	      "           -T | --timing 2           add timing delays to mimic a real TU58\n" \
-	      "           -s | --speed BAUD         set line speed [1200..3000000; default 9600]\n" \
+	      "           -s | --speed BAUD         set line speed to BAUD; default 9600\n" \
+	      "           -S | --stop BITS          set stop bits 1..2; default 1\n" \
 	      "           -p | --port PORT          set port to PORT [1..N or /dev/comN; default 1]\n" \
 	      "           -r | --read|rd FILENAME   readonly drive\n" \
 	      "           -w | --write FILENAME     read/write drive\n" \
@@ -242,11 +257,11 @@ int main (int argc,
 	      version, argv[0], NTU58-1);
 
     // give some info
-    info("serial port %s at %d baud", port, speed);
+    info("serial port %s at %d baud %d stop", port, speed, stop);
     if (mrspen) info("MRSP mode enabled (NOT fully tested - use with caution)");
 
     // setup serial and console ports
-    devinit(port, speed);
+    devinit(port, speed, stop);
     coninit();
     
     // play TU58

makefile

@@ -2,50 +2,47 @@
 # tu58em emulator makefile
 #
 
-ifeq ($(comm),mac)
-# UNIX comms model, but on a Mac
-PROG = tu58em
-COMM = -UWINCOMM -DMACOSX
-else ifeq ($(comm),win)
-# WINDOWS comms model
-PROG = tu58ew
-COMM = -DWINCOMM
-else # ifeq ($(comm),unix)
-# UNIX comms model
-PROG = tu58em
-COMM = -UWINCOMM
+# get operating system name
+OPSYS = $(shell uname -s)
+
+ifeq ($(OPSYS),Darwin)
+# mac: UNIX comms model, but on MACOSX
+OPTIONS = -DMACOSX
+LFLAGS = -lpthread
+BINDIR = /usr/local/bin
+else ifeq ($(OPSYS:CYGWIN%=CYGWIN),CYGWIN)
+# win: WINDOWS comms model under CYGWIN (any version)
+OPTIONS = -DCYGWIN -DWINCOMM
+LFLAGS = -lpthread -lrt
+BINDIR = /cygdrive/e/DEC/tools/exe
+else ifeq ($(OPSYS),Linux)
+# unix: UNIX comms model under LINUX, use PARMRK serial mode
+OPTIONS = -DLINUX -DUSE_PARMRK
+LFLAGS = -lpthread -lrt
+BINDIR = /usr/local/bin
+else # unknown environment
+OPTIONS =
+LFLAGS = -lpthread -lrt
+BINDIR = /usr/local/bin
 endif
 
-# put your binary installation directory here...
-BIN = /cygdrive/e/DEC/tools/exe
+# default program name, redefine PROG=xxx on command line if wanted
+PROG = tu58em
 
 # compiler flags and libraries
 CC = gcc
-CFLAGS = -I. -O3 -Wall -c $(COMM)
-ifeq ($(comm),mac)
-LFLAGS = -lpthread
-else
-LFLAGS = -lpthread -lrt
-endif
+CFLAGS = -I. -O3 -Wall -c $(OPTIONS)
 
 $(PROG) : main.o tu58drive.o file.o serial.o
 	$(CC) -o $@ main.o tu58drive.o file.o serial.o $(LFLAGS)
 
-all :
-	make --always comm=win
-	make clean
-	make --always comm=unix
-	make clean
-
-mac :
-	make --always comm=mac
-	make --clean
-
-installall :
-	make --always comm=win install
-	make clean
-	make --always comm=unix install
-	make clean
+config :
+	@echo "   OPSYS = \"$(OPSYS)\""
+	@echo "    PROG = \"$(PROG)\""
+	@echo "  BINDIR = \"$(BINDIR)\""
+	@echo "      CC = \"$(CC)\""
+	@echo "  CFLAGS = \"$(CFLAGS)\""
+	@echo "  LFLAGS = \"$(LFLAGS)\""
 
 clean :
 	-rm -f *.o
@@ -57,7 +54,7 @@ purge : clean
 	-rm -f $(PROG) $(PROG).exe
 
 install : $(PROG)
-	[ -d $(BIN) ] && cp $< $(BIN)
+	[ -d $(BINDIR) ] && cp $< $(BINDIR)
 
 serial.o : serial.c common.h
 	$(CC) $(CFLAGS) serial.c

serial.c

@@ -2,7 +2,7 @@
 // tu58 - Emulate a TU58 over a serial line
 //
 // Original (C) 1984 Dan Ts'o <Rockefeller Univ. Dept. of Neurobiology>
-// Update   (C) 2005-2016 Donald N North <ak6dn_at_mindspring_dot_com>
+// Update   (C) 2005-2017 Donald N North <ak6dn_at_mindspring_dot_com>
 //
 // All rights reserved.
 //
@@ -56,21 +56,21 @@
 #define IUCLC 0 // Not POSIX
 #define OLCUC 0 // Not POSIX
 #define CBAUD 0 // Not POSIX
-#endif
+#endif // MACOSX
 
 #include <termios.h>
 
 #define	BUFSIZE	256	// size of serial line buffers (bytes, each way)
 
 // serial output buffer
-static uint8_t wbuf[BUFSIZE];
+static uint8_t  wbuf[BUFSIZE];
 static uint8_t *wptr;
-static int32_t wcnt;
+static int32_t  wcnt;
 
 // serial input buffer
-static uint8_t rbuf[BUFSIZE];
+static uint8_t  rbuf[BUFSIZE];
 static uint8_t *rptr;
-static int32_t rcnt;
+static int32_t  rcnt;
 
 #ifdef WINCOMM
 // serial device descriptor, default to nada
@@ -78,6 +78,7 @@ static HANDLE hDevice = INVALID_HANDLE_VALUE;
 // async line parameters
 static DCB dcbSave;
 static COMMTIMEOUTS ctoSave;
+static uint8_t rxBreakSeen;
 #else // !WINCOMM
 // serial device descriptor, default to nada
 static int32_t device = -1;
@@ -197,6 +198,7 @@ void devrxinit (void)
 #ifdef WINCOMM
     if (!PurgeComm(hDevice, PURGE_RXABORT|PURGE_RXCLEAR))
 	error("devrxinit(): error=%d", GetLastError());
+    rxBreakSeen = 0;
 #else // !WINCOMM
     tcflush(device, TCIFLUSH);
 #endif // !WINCOMM
@@ -211,75 +213,26 @@ void devrxinit (void)
 
 
 //
-// wait for an error on the serial line
-// return NYI, OK, BREAK, ERROR flag
-//
-int32_t devrxerror (void)
-{
-#ifdef WINCOMM
-    // enable BREAK and ERROR events
-    OVERLAPPED ovlp = { 0 };
-    DWORD sts = 0;
-    if (!SetCommMask(hDevice, EV_BREAK|EV_ERR)) {
-	DWORD err = GetLastError();
-	if (err != ERROR_OPERATION_ABORTED)
-	    error("devrxerror(): SetCommMask() failed, error=%d", err);
-    }
-    // do the status check
-    ovlp.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
-    if (!WaitCommEvent(hDevice, &sts, &ovlp)) {
-	DWORD err = GetLastError();
-	if (err == ERROR_IO_PENDING) {
-	    if (WaitForSingleObject(ovlp.hEvent, INFINITE) == WAIT_OBJECT_0)
-		GetOverlappedResult(hDevice, &ovlp, &sts, FALSE);
-	} else {
-	    if (err != ERROR_OPERATION_ABORTED)
-		error("devrxerror(): WaitCommEvent() failed, error=%d", err);
-	}
-    }
-    // done
-    CloseHandle(ovlp.hEvent);
-    // indicate either a break or some other error or OK
-    return (sts & (CE_BREAK|CE_FRAME)) ? DEV_BREAK : (sts ? DEV_ERROR : DEV_OK);
-#else // !WINCOMM
-    // not implemented
-    return DEV_NYI;
-#endif // !WINCOMM
-}
-
-
-
-//
-// return number of characters available
+// return number of characters available, get more if receive buffer is empty
 //
 int32_t devrxavail (void)
 {
     // get more characters if none available
     if (rcnt <= 0) {
 #ifdef WINCOMM
-	OVERLAPPED ovlp = { 0 };
 	COMSTAT stat;
 	DWORD acnt = 0;
+	DWORD ncnt = 0;
 	DWORD sts = 0;
 	// clear state
 	if (!ClearCommError(hDevice, &sts, &stat))
 	    error("devrxavail(): ClearCommError() failed");
-	if (debug && (sts || stat.cbInQue))
-	    info("devrxavail(): status=0x%04X avail=%d", sts, stat.cbInQue);
-	// do the read if something there
-	if (stat.cbInQue > 0) {
-	    ovlp.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
-	    if (!ReadFile(hDevice, rbuf, sizeof(rbuf), &acnt, &ovlp)) {
-		DWORD err = GetLastError();
-		if (err == ERROR_IO_PENDING) {
-		    if (WaitForSingleObject(ovlp.hEvent, INFINITE) == WAIT_OBJECT_0)
-			GetOverlappedResult(hDevice, &ovlp, &acnt, FALSE);
-		} else {
-		    error("devrxavail(): error=%d", err);
-		}
-	    }
-	    CloseHandle(ovlp.hEvent);
-	}
+	// do the read if something there, at most size of buffer
+	ncnt = stat.cbInQue > sizeof(rbuf) ? sizeof(rbuf) : stat.cbInQue;
+	if (!ReadFile(hDevice, rbuf, ncnt, &acnt, NULL))
+	    error("devrxavail(): error=%d", GetLastError());
+	// check for break
+	if (sts & CE_BREAK) rxBreakSeen = 1;
 	// done
 	rcnt = acnt;
 #else // !WINCOMM
@@ -296,7 +249,7 @@ int32_t devrxavail (void)
 
 
 //
-// write characters direct to device
+// write characters direct to device from transmit buffer
 //
 int32_t devtxwrite (uint8_t *buf,
 		    int32_t cnt)
@@ -304,28 +257,16 @@ int32_t devtxwrite (uint8_t *buf,
     // write characters if asked, return number written
     if (cnt > 0) {
 #ifdef WINCOMM
-	OVERLAPPED ovlp = { 0 };
 	COMSTAT stat;
 	DWORD acnt = 0;
 	DWORD sts = 0;
 	// clear state
 	if (!ClearCommError(hDevice, &sts, &stat))
 	    error("devtxwrite(): ClearCommError() failed");
-	if (debug && (sts || stat.cbOutQue))
-	    info("devtxwrite(): status=0x%04X remain=%d", sts, stat.cbOutQue);
 	// do the write
-	ovlp.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
-	if (!WriteFile(hDevice, buf, cnt, &acnt, &ovlp)) {
-	    DWORD err = GetLastError();
-	    if (err == ERROR_IO_PENDING) {
-		if (WaitForSingleObject(ovlp.hEvent, INFINITE) == WAIT_OBJECT_0)
-		    GetOverlappedResult(hDevice, &ovlp, &acnt, FALSE);
-	    } else {
-		error("devtxwrite(): error=%d", err);
-	    }
-	}
+	if (!WriteFile(hDevice, buf, cnt, &acnt, NULL))
+	    error("devtxwrite(): error=%d", GetLastError());
 	// done
-	CloseHandle(ovlp.hEvent);
 	return acnt;
 #else // !WINCOMM
 	return write(device, buf, cnt);
@@ -370,14 +311,71 @@ void devtxflush (void)
 //
 // return char from rbuf, wait until some arrive
 //
-uint8_t devrxget (void)
+uint8_t devrxget (uint8_t *flg)
 {
-    // get more characters if none available
-    while (devrxavail() <= 0) /*spin*/;
+    uint8_t c;
 
-    // count, return next character
+#ifdef USE_PARMRK
+    // get more bytes if none available
+    while (rcnt <= 0) { (void)devrxavail(); }
+    // at least one available
     rcnt--;
-    return *rptr++;
+    // check if escaped or normal
+    if ((c = *rptr++) == 0377) {
+        // escape byte seen
+        while (rcnt <= 0) { (void)devrxavail(); }
+        // at least one available
+        rcnt--;
+        // check if escape or not
+        if ((c = *rptr++) == 0377) {
+            // 377,377 seen; return 377
+            *flg = DEV_NORMAL;
+            return c;
+        } else {
+            // non-escape byte seen, so get one more byte
+            while (rcnt <= 0) { (void)devrxavail(); }
+            // at least one available
+            rcnt--;
+            // check if NULL
+            if ((c = *rptr++) == 0000) {
+                // 377,000,000 seen; signals a BREAK, return 000 byte
+                *flg = DEV_BREAK;
+                return c;
+            } else {
+                // 377,000,NNN seen; signals byte NNN parity/framing error
+                *flg = DEV_ERROR;
+                return c;
+            }
+        }
+    } else {
+        // return normal data byte
+        *flg = DEV_NORMAL;
+        return c;
+    }
+#else // !USE_PARMRK
+    // get more characters if none available
+    while (rcnt <= 0) { (void)devrxavail(); }
+    // at least one available
+    rcnt--;
+    // get data byte
+    c = *rptr++;
+#ifdef WINCOMM
+    // check if this byte should be flagged as a BREAK
+    // for lack of a better algorithm, we flag the first
+    // ZERO byte after the rxBreakSeen flag is set as BREAK
+    if (c == 000 && rxBreakSeen) {
+	*flg = DEV_BREAK;
+	rxBreakSeen = 0;
+    } else {
+	*flg = DEV_NORMAL;
+    }
+#else // !WINCOMM
+    // return normal data byte
+    *flg = DEV_NORMAL;
+#endif // !WINCOMM
+    // return data byte
+    return c;
+#endif // !USE_PARMRK
 }
 
 
@@ -405,49 +403,89 @@ void devtxput (uint8_t c)
 static int32_t devbaud (int32_t rate)
 {
 #ifdef WINCOMM
-    static int32_t baudlist[] = { 3000000, 3000000,
-				  2500000, 2500000,
-				  2000000, 2000000,
-				  1500000, 1500000,
-				  1152000, 1152000,
-				  1000000, 1000000,
-				  921600,  921600,
-				  576000,  576000,
-				  500000,  500000,
-				  460800,  460800,
-				  256000,  256000,
-				  230400,  230400,
-				  115200,  115200,
-				  57600,   57600,
-				  38400,   38400,
-				  19200,   19200,
-				  9600,    9600,
-				  4800,    4800,
-				  2400,    2400,
-				  1200,    1200,
-			          -1,	   -1 };
+    static int32_t baudlist[] = {
+	3000000, 3000000,
+	2500000, 2500000,
+	2000000, 2000000,
+	1500000, 1500000,
+	1152000, 1152000,
+	1000000, 1000000,
+	921600,  921600,
+	576000,  576000,
+	500000,  500000,
+	460800,  460800,
+	230400,  230400,
+	115200,  115200,
+	57600,   57600,
+	38400,   38400,
+	19200,   19200,
+	9600,    9600,
+	4800,    4800,
+	2400,    2400,
+	1200,    1200,
+	-1,	   -1
+    };
 #else // !WINCOMM
-    static int32_t baudlist[] = { 3000000, B3000000,
-				  2500000, B2500000,
-				  2000000, B2000000,
-				  1500000, B1500000,
-				  1152000, B1152000,
-				  1000000, B1000000,
-				  921600,  B921600,
-				  576000,  B576000,
-				  500000,  B500000,
-				  460800,  B460800,
-				  256000,  B256000,
-				  230400,  B230400,
-				  115200,  B115200,
-				  57600,   B57600,
-				  38400,   B38400,
-				  19200,   B19200,
-				  9600,    B9600,
-				  4800,    B4800,
-				  2400,    B2400,
-				  1200,    B1200,
-			          -1,	    -1 };
+    static int32_t baudlist[] = {
+#ifdef B3000000
+	3000000, B3000000,
+#endif // B3000000
+#ifdef B2500000
+	2500000, B2500000,
+#endif // B2500000
+#ifdef B2000000
+	2000000, B2000000,
+#endif // B2000000
+#ifdef B1500000
+	1500000, B1500000,
+#endif // B1500000
+#ifdef B1152000
+	1152000, B1152000,
+#endif // B1152000
+#ifdef B1000000
+	1000000, B1000000,
+#endif // B1000000
+#ifdef B921600
+	921600,  B921600,
+#endif // B921600
+#ifdef B576000
+	576000,  B576000,
+#endif // B576000
+#ifdef B500000
+	500000,  B500000,
+#endif // B500000
+#ifdef B460800
+	460800,  B460800,
+#endif // B460800
+#ifdef B230400
+	230400,  B230400,
+#endif // B230400
+#ifdef B115200
+	115200,  B115200,
+#endif // B115200
+#ifdef B57600
+	57600,   B57600,
+#endif // B57600
+#ifdef B38400
+	38400,   B38400,
+#endif // B38400
+#ifdef B19200
+	19200,   B19200,
+#endif // B19200
+#ifdef B9600
+	9600,    B9600,
+#endif // B9600
+#ifdef B4800
+	4800,    B4800,
+#endif // B4800
+#ifdef B2400
+	2400,    B2400,
+#endif // B2400
+#ifdef B1200
+	1200,    B1200,
+#endif // B1200
+	-1,	    -1
+    };
 #endif // !WINCOMM
     int32_t *p = baudlist;
     int32_t r;
@@ -465,7 +503,8 @@ static int32_t devbaud (int32_t rate)
 // open/initialize serial port
 //
 void devinit (char *port,
-	      int32_t speed)
+	      int32_t speed,
+	      int32_t stop)
 {
 #ifdef WINCOMM
 
@@ -480,9 +519,17 @@ void devinit (char *port,
     int32_t uid = getuid();
     setreuid(euid, -1);
     if (sscanf(port, "%u", &n) == 1) sprintf(name, "\\\\.\\COM%d", n); else strcpy(name, port);
-    hDevice = CreateFile(name, GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING,
-			 FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED, NULL);
+    // open port in non-overlapped I/O mode
+    hDevice = CreateFile(name,
+			 GENERIC_READ | GENERIC_WRITE,
+			 0,
+			 NULL,
+			 OPEN_EXISTING,
+			 FILE_ATTRIBUTE_NORMAL,
+			 NULL);
     if (hDevice == INVALID_HANDLE_VALUE) fatal("no serial line [%s]", name);
+
+    // we own the port
     setreuid(uid, euid);
 
     // get current line params, error if not a serial port
@@ -515,7 +562,7 @@ void devinit (char *port,
     dcb.fAbortOnError = FALSE;
     dcb.ByteSize = 8;
     dcb.Parity = NOPARITY;
-    dcb.StopBits = TWOSTOPBITS;
+    dcb.StopBits = (stop == 2) ? TWOSTOPBITS : ONESTOPBIT;
 
     // timing/read param
     cto.ReadIntervalTimeout = MAXDWORD;
@@ -539,10 +586,10 @@ void devinit (char *port,
     // open serial port
     int32_t euid = geteuid();
     int32_t uid = getuid();
-    setreuid(euid, -1);
+    if (setreuid(euid, -1)) fatal("setreuid(euid,-1) failed");
     if (sscanf(port, "%u", &n) == 1) sprintf(name, "/dev/ttyS%u", n-1); else strcpy(name, port);
     if ((device = open(name, O_RDWR|O_NDELAY|O_NOCTTY)) < 0) fatal("no serial line [%s]", name);
-    setreuid(uid, euid);
+    if (setreuid(uid, euid)) fatal("setreuid(uid,euid) failed");
 
     // get current line params, error if not a serial port
     if (tcgetattr(device, &lineSave)) fatal("not a serial device [%s]", name);
@@ -550,17 +597,15 @@ void devinit (char *port,
     // copy current parameters
     line = lineSave;
 
-    // set baud rate
-    if (devbaud(speed) == -1)
-	error("illegal serial speed %d., ignoring", speed);
-    else
-	line.c_ospeed = line.c_ispeed = devbaud(speed);
-
     // input param
     line.c_iflag &= ~( IGNBRK | BRKINT | IMAXBEL | INPCK | ISTRIP |
 		       INLCR  | IGNCR  | ICRNL   | IXON  | IXOFF  |
 		       IUCLC  | IXANY  | PARMRK  | IGNPAR );
+#ifdef USE_PARMRK
+    line.c_iflag |=  ( PARMRK | INPCK );
+#else // !USE_PARMRK
     line.c_iflag |=  ( 0 );
+#endif // !USE_PARMRK
 
     // output param
     line.c_oflag &= ~( OPOST  | OLCUC | OCRNL | ONLCR | ONOCR |
@@ -571,7 +616,10 @@ void devinit (char *port,
     // control param
     line.c_cflag &= ~( CBAUD  | CSIZE | CSTOPB  | PARENB | PARODD |
 		       HUPCL | CRTSCTS | CLOCAL | CREAD );
-    line.c_cflag |=  ( CLOCAL | CREAD | CS8 | CSTOPB ); // 8b+2stop
+    line.c_cflag |=  ( CLOCAL | CREAD | CS8 );
+
+    // set two stop bits if requested, else default to one
+    if (stop == 2) line.c_cflag |= CSTOPB;
 
     // local param
     line.c_lflag &= ~( ISIG   | ICANON  | ECHO   | ECHOE  | ECHOK  |
@@ -583,8 +631,18 @@ void devinit (char *port,
     line.c_cc[VMIN] = 1; // return a min of 1 chars
     line.c_cc[VTIME] = 0; // no timer
 
-    // ok, set new param
+    // flush all existing input data
     tcflush(device, TCIFLUSH);
+
+    // set baud rate, if it is legal
+    if (devbaud(speed) == -1) {
+	error("illegal serial speed %d., ignoring", speed);
+    } else {
+	cfsetispeed(&line, devbaud(speed));
+	cfsetospeed(&line, devbaud(speed));
+    }
+
+    // set new device parameters
     tcsetattr(device, TCSANOW, &line);
 
     // and non-blocking also

tu58drive.c

@@ -2,7 +2,7 @@
 // tu58 - Emulate a TU58 over a serial line
 //
 // Original (C) 1984 Dan Ts'o <Rockefeller Univ. Dept. of Neurobiology>
-// Update   (C) 2005-2016 Donald N North <ak6dn_at_mindspring_dot_com>
+// Update   (C) 2005-2017 Donald N North <ak6dn_at_mindspring_dot_com>
 //
 // All rights reserved.
 //
@@ -48,22 +48,21 @@
 #include "common.h"
 
 #include <pthread.h>
+#include <setjmp.h>
 
 #include "tu58.h"
 
 #ifdef MACOSX
-// clock_gettime() is not available under OSX
+// clock_gettime() is not available under MACOSX
 #define CLOCK_REALTIME 1
 #include <mach/mach_time.h>
-
-void clock_gettime(int dummy, timespec_t *t) {
+void clock_gettime (int dummy, struct timespec *t) {
     uint64_t mt;
     mt = mach_absolute_time();
     t->tv_sec  = mt / 1000000000;
     t->tv_nsec = mt % 1000000000;
 }
-#endif
-
+#endif // MACOSX
 
 // delays for modeling device access
 
@@ -90,7 +89,7 @@ uint8_t mrsp = 0;			// set nonzero to indicate MRSP mode is active
 static uint8_t doinit = 0;	// set nonzero to indicate should send INITs continuously
 static uint8_t runonce = 0;	// set nonzero to indicate emulator has been run
 static pthread_t th_run;	// emulator thread id
-static pthread_t th_monitor;	// monitor thread id
+static jmp_buf rx_break_env;    // longjmp state for when a BREAK is detected on rx
 
 
 
@@ -138,6 +137,26 @@ static void reinit (void)
 
 
 
+//
+// read a byte from the host, process BREAK if seen
+//
+static uint8_t rxget (void)
+{
+    uint8_t state;
+    uint8_t c;
+
+    // get a byte and state flag
+    c = devrxget(&state);
+
+    // seen a BREAK on the rx line, so abort this packet
+    if (state == DEV_BREAK) longjmp(rx_break_env, c);
+
+    // return the byte
+    return c;
+}
+
+
+
 //
 // read of boot is not packetized, is just raw data
 //
@@ -148,7 +167,7 @@ static void bootio (void)
     uint8_t buffer[TU_BOOT_LEN];
 
     // check unit number for validity
-    unit = devrxget();
+    unit = rxget();
     if (fileunit(unit)) {
 	error("bootio bad unit %d", unit);
 	return;
@@ -238,7 +257,7 @@ static void wait4cont (uint8_t code)
 
     // wait for a CONT to arrive, but only so long
     do {
-	c = devrxget();
+	c = rxget();
 	if (debug) info("wait4cont(): char=0x%02X", c);
     } while (c != TUF_CONT && --maxchar >= 0);
 
@@ -291,7 +310,7 @@ static int32_t getpacket (tu_packet *pkt)
     uint16_t rcvchk, expchk;
 
     // get remaining packet bytes, incl two checksum bytes
-    while (--count >= 0) *ptr++ = devrxget();
+    while (--count >= 0) *ptr++ = rxget();
 
     // get checksum bytes
     rcvchk = (ptr[-1]<<8) | (ptr[-2]<<0);
@@ -483,7 +502,7 @@ static void tuwrite (tu_cmdpkt *pk)
 	// loop until we see data flag
 	do {
 	    last = dk.flag;
-	    dk.flag = devrxget();
+	    dk.flag = rxget();
 	    if (debug) info("flag=0x%02X last=0x%02X", dk.flag, last);
 	    if (last == TUF_INIT && dk.flag == TUF_INIT) {
 		// two in a row is special
@@ -505,7 +524,7 @@ static void tuwrite (tu_cmdpkt *pk)
 	} while (dk.flag != TUF_DATA);
 
 	// byte following data flag is packet data length
-	dk.length = devrxget();
+	dk.length = rxget();
 
 	// get remainder of the data packet
 	if (getpacket((tu_packet *)&dk)) {
@@ -577,7 +596,7 @@ static void command (int8_t flag)
     time_end.tv_nsec   = 0;
 
     pk.flag = flag;
-    pk.length = devrxget();
+    pk.length = rxget();
 
     // check control packet length ... if too long flush it
     if (pk.length > sizeof(tu_cmdpkt)) {
@@ -729,11 +748,18 @@ static void* run (void* none)
     doinit = !nosync; // start sending init flags?
 
     // say hello
-    info("emulator %sstarted", runonce++ ? "re" : "");
+    info("TU58 emulator %sstarted", runonce++ ? "re" : "");
 
     // loop forever ... almost
     for (;;) {
 
+        // setup for when a BREAK is detected
+        if (setjmp(rx_break_env)) {
+            // return here when we get a BREAK on the rx input
+            if (debug) info("<BREAK> seen");
+            // fall thru to main loop
+        }
+
 	// loop while no characters are available
 	while (devrxavail() == 0) {
 	    // delays and printout only if not VAX
@@ -752,7 +778,7 @@ static void* run (void* none)
 
 	// process received characters
 	last = flag;
-	flag = devrxget();
+	flag = rxget();
 	if (debug) info("flag=0x%02X last=0x%02X", flag, last);
 
 	switch (flag) {
@@ -818,48 +844,6 @@ static void* run (void* none)
 
 
 
-//
-// monitor for break/error on line, restart emulator if seen
-//
-static void* monitor (void* none)
-{
-    int32_t sts;
-
-    for (;;) {
-
-	// check for any error
-	switch (sts = devrxerror()) {
-	case DEV_ERROR: // error
-	case DEV_BREAK: // break
-	    // kill and restart the emulator
-	    if (verbose) info("BREAK detected");
-#ifdef THIS_DOES_NOT_YET_WORK_RELIABLY
-	    if (pthread_cancel(th_run))
-		error("unable to cancel emulation thread");
-	    if (pthread_join(th_run, NULL))
-		error("unable to join on emulation thread");
-	    if (pthread_create(&th_run, NULL, run, NULL))
-		error("unable to restart emulation thread");
-#endif // THIS_DOES_NOT_YET_WORK_RELIABLY
-	    break;
-	case DEV_OK: // OK
-	    break;
-	case DEV_NYI: // not yet implemented
-	    return (void*)1;
-	default: // something else...
-	    error("monitor(): unknown flag %d", sts);
-	    break;
-	}
-	// bit of a delay, loop again
-	delay_ms(5);
-
-    }
-
-    return (void*)0;
-}
-
-
-
 //
 // start tu58 drive emulation
 //
@@ -870,17 +854,13 @@ void tu58drive (void)
 	fatal("illegal BLOCKSIZE (%d) / TU_DATA_LEN (%d) ratio", BLOCKSIZE, TU_DATA_LEN);
 
     // say hello
-    info("TU58 emulation start");
+    info("TU58 start");
     info("R restart, S toggle send init, V toggle verbose, D toggle debug, Q quit");
 
     // run the emulator
     if (pthread_create(&th_run, NULL, run, NULL))
 	error("unable to create emulation thread");
 
-    // run the monitor
-    if (pthread_create(&th_monitor, NULL, monitor, NULL))
-	error("unable to create monitor thread");
-
     // loop on user input
     for (;;) {
 	uint8_t c;
@@ -912,8 +892,6 @@ void tu58drive (void)
 		    error("unable to restart emulation thread");
 	    } else if (c == 'Q') {
 		// kill the emulator and exit
-		if (pthread_cancel(th_monitor))
-		    error("unable to cancel monitor thread");
 		if (pthread_cancel(th_run))
 		    error("unable to cancel emulation thread");
 		break;
@@ -930,7 +908,7 @@ void tu58drive (void)
 	error("unable to join on emulation thread");
 
     // all done
-    info("TU58 emulation end");
+    info("TU58 end");
     return;
 }