swtp/swtp_sio.c

/* swtp_sio: SWTP serial I/O card

Copyright (c) 2005, William Beech

	Permission is hereby granted, free of charge, to any person obtaining a
	copy of this software and associated documentation files (the "Software"),
	to deal in the Software without restriction, including without limitation
	the rights to use, copy, modify, merge, publish, distribute, sublicense,
	and/or sell copies of the Software, and to permit persons to whom the
	Software is furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in
	all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
	Willaim Beech BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
	IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

	Except as contained in this notice, the name of William A. Beech shall not
	be used in advertising or otherwise to promote the sale, use or other dealings
	in this Software without prior written authorization from William A. Beech.
   
	Based on work by Charles E Owen (c) 1997 and Peter Schorn (c) 2002-2005

    These functions support a simulated SWTP MP-S interface card.
    The card had two physical I/O ports which could be connected
    to any serial I/O device that would connect to a current loop
    or RS232 interface.  Available baud rates were jumper selectable
    for each port from 110 to 9600.  The ports appear at all 4 addresses.
	This fact is used by SWTBUG to determine the presence of the MP-S vice
	MP-C serial card.

    All I/O is via either programmed I/O or interrupt controlled I/O.
    It has a status port and a data port.  A write to the status port
    can select some options for the device (0x03 will reset the port).
    A read of the status port gets the port status:

    +---+---+---+---+---+---+---+---+
    | I | P | O | F |CTS|DCD|TXE|RXF|
    +---+---+---+---+---+---+---+---+

	RXF - A 1 in this bit position means a character has been received
    	  on the data port and is ready to be read.
    TXE - A 1 in this bit means the port is ready to receive a character
    	  on the data port and transmit it out over the serial line.
 
    A read to the data port gets the buffered character, a write
    to the data port writes the character to the device.
*/

#include	<stdio.h>
#include	<ctype.h>

#include "swtp_defs.h"

#define	UNIT_V_ANSI	(UNIT_V_UF + 0)		// ANSI mode
#define UNIT_ANSI	(1 << UNIT_V_ANSI)

t_stat sio_svc (UNIT *uptr);
t_stat sio_reset (DEVICE *dptr);
t_stat ptr_svc (UNIT *uptr);
t_stat ptr_reset (DEVICE *dptr);
t_stat ptp_svc (UNIT *uptr);
t_stat ptp_reset (DEVICE *dptr);

int32 ptr_stopioe = 0, ptp_stopioe = 0;	// stop on error

// MP-S Standard I/O Data Structures

UNIT sio_unit = { UDATA (&sio_svc, 0, 0),
			 KBD_POLL_WAIT };

REG sio_reg[] = {
	{ ORDATA (DATA, sio_unit.buf, 8) },
	{ ORDATA (STAT, sio_unit.u3, 8) },
	{ NULL }  };

MTAB sio_mod[] = {
	{ UNIT_ANSI, 0, "TTY", "TTY", NULL },
	{ 0 }  };

DEVICE sio_dev = {
	"MP-S", &sio_unit, sio_reg, sio_mod,
	1, 10, 31, 1, 8, 8,
	NULL, NULL, &sio_reset,
	NULL, NULL, NULL };

UNIT ptr_unit = { UDATA (&ptr_svc, UNIT_SEQ + UNIT_ATTABLE, 0),
			 KBD_POLL_WAIT };
DEVICE ptr_dev = {
	"PTR", &ptr_unit, NULL, NULL,
	1, 10, 31, 1, 8, 8,
	NULL, NULL, &ptr_reset,
	NULL, NULL, NULL };

UNIT ptp_unit = { UDATA (&ptp_svc, UNIT_SEQ + UNIT_ATTABLE, 0),
			 KBD_POLL_WAIT };
DEVICE ptp_dev = {
	"PTP", &ptp_unit, NULL, NULL,
	1, 10, 31, 1, 8, 8,
	NULL, NULL, &ptp_reset,
	NULL, NULL, NULL };

/*  Service routines to handle simulator functions */

/* service routine - actually gets char & places in buffer */

int32 ptp_rdr(int32 io, int32 data);

int32	ptp_flag = 0, ptr_flag = 0;

/* console input service routine */

t_stat sio_svc (UNIT *uptr)
{
	int32 temp;

	sim_activate (&sio_unit, sio_unit.wait); // continue poll
	if ((temp = sim_poll_kbd ()) < SCPE_KFLAG)
		return temp;				// no char or error?
	sio_unit.buf = temp & 0xFF;		// Save char
	sio_unit.u3 |= 0x01;            // Set RXF flag

	/* Do any special character handling here */

	sio_unit.pos++;					// step character count
	return SCPE_OK;
}

/* paper tape reader input service routine */

t_stat ptr_svc (UNIT *uptr)
{
    return SCPE_OK;
}

/* paper tape punch output service routine */

t_stat ptp_svc (UNIT *uptr)
{
	return SCPE_OK;
}

/* Reset console */

t_stat sio_reset (DEVICE *dptr)
{
	sio_unit.buf = 0;				// Data buffer
	sio_unit.u3 = 0x02;				// Status buffer
	sim_activate (&sio_unit, sio_unit.wait); // activate unit
	return SCPE_OK;
}

/* Reset paper tape reader */

t_stat ptr_reset (DEVICE *dptr)
{
	ptr_unit.buf = 0;
	ptr_unit.u3 = 0x02;
	sim_cancel (&ptr_unit);			// deactivate unit
	return SCPE_OK;
}

/* Reset paper tape punch */

t_stat ptp_reset (DEVICE *dptr)
{
	ptp_unit.buf = 0;
	ptp_unit.u3 = 0x02;
	sim_cancel (&ptp_unit);			// deactivate unit
	return SCPE_OK;
}

/* 	I/O instruction handlers, called from the CPU module when a
   	read or write occur to addresses 0x8000-0x801F.

   	Each function is passed an 'io' flag, where 0 means a read from
   	the port, and 1 means a write to the port.  On input, the actual
	input is passed as the return value, on output, 'data' is written
	to the device.

	This code emulates a SWTP MP-S Serial Card with a Model 33 Teletype
	attached.  The Model 33 uses DC1-DC4 codes to enable or disable the
	paper tape reader and punch.  Those devices are defined in this module,
	and the code built to emulate those functions if the PTP and/or PTR
	are attached in the simulator.
*/

/* Port 1 (0x8004-0x8007) controls the Model 33 Teletype */

int32 ptr_flg1 = 0;
int32 odata, status;


int32 sio0s(int32 io, int32 data)
{
	UNIT *uptr;

	if (io == 0) {					// control register read
		if (ptr_flag) {				// reader enabled?
			if ((ptr_unit.flags & UNIT_ATT) == 0)	// attached?
				ptr_unit.u3 &= 0xFE; // no, clear RXF flag 
			else {
				uptr = ptr_dev.units;// not EOF?
				if (feof(uptr -> fileref))
					ptr_unit.u3 &= 0xFE;
				else
					ptr_unit.u3 |= 0x01;
			}
			return (status = ptr_unit.u3);	// no - done
		} else {
			return (status = sio_unit.u3);	// return console status
		}
	} else {						// control register write
    	if (data == 0x03) {			// reset port!
            sio_unit.u3 = 0x02;		// reset console
            sio_unit.buf = 0;
            sio_unit.pos = 0;
        	ptr_unit.u3 = 0x02;		// reset reader
            ptr_unit.buf = 0;
            ptr_unit.pos = 0;
        	ptp_unit.u3 = 0x02;		// reset punch
            ptp_unit.buf = 0;
            ptp_unit.pos = 0;
        }
   	return (status = 0);						// invalid io
    }
}

int32 sio0d(int32 io, int32 data)
{
    UNIT *uptr;

	if (io == 0) {					// data register read
		if (ptr_flag) {				// RDR enabled?
			if ((ptr_unit.flags & UNIT_ATT) == 0)	// attached?
				return 0;			// no, done
//			printf("ptr_unit.u3=%02X\n", ptr_unit.u3);
			if ((ptr_unit.u3 & 0x01) == 0) {	// yes, more data?
//				printf("Returning old %02X\n", odata);  // no, return previous byte
			 	return (odata & 0xFF);
			}
			uptr = ptr_dev.units;	// get data byte
			if ((odata = getc(uptr -> fileref)) == EOF) { // end of file?
//				printf("Got EOF\n");
			    ptr_unit.u3 &= 0xFE; // clear RXF flag	
			    return (odata = 0);			// no data
			}
//			printf("Returning new %02X\n", odata);
			ptr_unit.pos++;			// step character count
			ptr_unit.u3 &= 0xFE;	// clear RXF flag	
			return (odata & 0xFF);	// return character
		} else {
			sio_unit.u3 &= 0xFE;	// clear RXF flag
			return (odata = sio_unit.buf);	// return next char
		}
    } else {						// data register write
		if (isprint(data) || data == '\r' || data == '\n') { // printable?
    		sim_putchar(data);		// print character on console
			if (ptp_flag && ptp_unit.flags & UNIT_ATT) { // PTP enabled & attached?
    			uptr = ptp_dev.units; // punch character to file
    			putc(data, uptr -> fileref);
				ptp_unit.pos++;		// step character counter
			}
		} else {					// DC1-DC4 control Reader/Punch
			switch (data) {
				case 0x11:			// RDR on
					ptr_flag = 1;
					ptr_flg1 = 0;
					ptr_unit.u3 |= 0x01;
//					printf("Reader on\r\n");
					break;
				case 0x12:			// PTP on
					ptp_flag = 1;
					ptp_unit.u3 |= 0x02;
//					printf("Punch on\r\n");
					break;
				case 0x13:			// RDR off
					ptr_flag = 0;
//					printf("Reader off-%d bytes read\r\n", ptr_unit.pos);
					break;
				case 0x14:			// PTP off
					ptp_flag = 0;
//					printf("Punch off-%d bytes written\r\n", ptp_unit.pos);
					break;
				default:			// ignore all other characters
					break;
			}
		}
    }
    return (odata = 0);
}

/*	because each port appears at 2 addresses and this fact is used
	to determine if it is a MP-C or MP-S repeatedly in the SWTBUG
	monitor, this code assures that reads of the high ports return
	the same data as was read the last time on the low ports.
*/

int32 sio1s(int32 io, int32 data)
{
        return status;
}

int32 sio1d(int32 io, int32 data)
{
    return odata;
}