diff --git a/PDP10/kx10_defs.h b/PDP10/kx10_defs.h
index 6dcbd17..bc3fda2 100644
--- a/PDP10/kx10_defs.h
+++ b/PDP10/kx10_defs.h
@@ -528,6 +528,7 @@ extern DEVICE   kmc_dev;
 extern DEVICE   dup_dev;
 extern DEVICE   tcu_dev;
 extern DEVICE   ddc_dev;
+extern DEVICE   tym_dev;
 
 #if KS
 
@@ -798,6 +799,9 @@ extern void ka10_lights_clear_aux (int);
 #if MAGIC_SWITCH && !KA && !ITS
 #error "Magic switch only valid on KA10 with ITS mods"
 #endif
+#if KI
+#define NUM_DEVS_TYM    1
+#endif
 
 /* Global data */
 
diff --git a/PDP10/kx10_sys.c b/PDP10/kx10_sys.c
index d048c9e..01c2b50 100644
--- a/PDP10/kx10_sys.c
+++ b/PDP10/kx10_sys.c
@@ -238,6 +238,9 @@ DEVICE *sim_devices[] = {
 #endif
 #if NUM_DEVS_DDC > 0
     &ddc_dev,
+#endif
+#if NUM_DEVS_TYM > 0
+    &tym_dev,
 #endif
     NULL
     };
diff --git a/PDP10/kx10_tym.c b/PDP10/kx10_tym.c
new file mode 100644
index 0000000..b55141d
--- /dev/null
+++ b/PDP10/kx10_tym.c
@@ -0,0 +1,687 @@
+/* kx10_tym.c: TYM, interface to Tymbase and Tymnet.
+
+   Copyright (c) 2022, Lars Brinkhoff
+
+   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
+   LARS BRINKHOFF 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.
+*/
+
+
+#include "kx10_defs.h"
+#include "sim_tmxr.h"
+
+#ifndef NUM_DEVS_TYM
+#define NUM_DEVS_TYM 0
+#endif
+
+#if NUM_DEVS_TYM > 0
+
+#define TYM_NAME        "TYM"
+#define MAX_LINES       32      /* Maximum found in the wild. */
+
+#define KEY    0633751506262LL  /* Base key. */
+#define BASE   02000            /* Default base address. */
+#define SIZE   01000            /* Default size. */
+
+#define LOCK   000              /* Key. */
+#define DUMP   002              /* Base dump loc * 16. */
+#define IRNG   003              /* Input ring loc * 16. */
+#define ISIZ   004              /* Input ring size * 16. */
+#define IHP    005              /* Host set input pointer. */
+#define IBP    006              /* Base set input pointer. */
+#define ORNG   007              /* Output ring loc * 16. */
+#define OSIZ   010              /* Output ring size * 16. */
+#define OHP    011              /* Host set output pointer. */
+#define OBP    012              /* Base set output pointer. */
+#define BCRSH  013              /* Base set crash indicator + reason. */
+#define HCRSH  014              /* Host set crash reason. */
+
+#define TYMBAS_ANS   001
+#define TYMBAS_SHT   002
+#define TYMBAS_CRS   003
+#define TYMBAS_DIE   004
+#define TYMBAS_NSP   005
+#define TYMBAS_LOG   006
+#define TYMBAS_AUX   007
+#define TYMBAS_NOP   010
+#define TYMBAS_OUP   011
+#define TYMBAS_GOB   012
+#define TYMBAS_ZAP   013
+#define TYMBAS_EDC   014
+#define TYMBAS_LDC   015
+#define TYMBAS_GRN   016
+#define TYMBAS_RED   017
+#define TYMBAS_YEL   020
+#define TYMBAS_ORG   021
+#define TYMBAS_HNG   022
+#define TYMBAS_ETM   023
+#define TYMBAS_LTM   024
+#define TYMBAS_LOS   025
+#define TYMBAS_SUP   026
+#define TYMBAS_SUR   027
+#define TYMBAS_AXC   030
+#define TYMBAS_TSP   031
+#define TYMBAS_TSR   032
+#define TYMBAS_SAD   033
+#define TYMBAS_ECN   034
+#define TYMBAS_ECF   035
+#define TYMBAS_TCS   036
+#define TYMBAS_TCP   037
+#define TYMBAS_TCR   040
+#define TYMBAS_HSI   041
+#define TYMBAS_DATA  0200
+
+static t_stat tym_reset(DEVICE *dptr);
+static t_stat tym_attach(UNIT * uptr, CONST char * cptr);
+static t_stat tym_detach(UNIT * uptr);
+static t_stat tym_interface_srv(UNIT *);
+static t_stat tym_alive_srv(UNIT *);
+static t_stat tym_input_srv(UNIT *);
+static t_stat tym_output_srv(UNIT *);
+static const char *tym_description(DEVICE *dptr);
+
+static TMLN tym_ldsc[MAX_LINES] = { 0 };
+static TMXR tym_desc = { MAX_LINES, 0, 0, tym_ldsc };
+
+static UNIT tym_unit[] = {
+    { UDATA(tym_input_srv, TT_MODE_8B|UNIT_IDLE|UNIT_ATTABLE, 0) },
+    { UDATA(tym_output_srv, UNIT_IDLE, 0) },
+    { UDATA(tym_interface_srv, UNIT_IDLE, 0) },
+    { UDATA(tym_alive_srv, UNIT_IDLE, 0) }
+};
+
+static MTAB tym_mod[] = {
+    { MTAB_XTD|MTAB_VDV|MTAB_VALR, 1, NULL, "DISCONNECT",
+        &tmxr_dscln, NULL, &tym_desc, "Disconnect a specific line" },
+    { UNIT_ATT, UNIT_ATT, "SUMMARY", NULL,
+        NULL, &tmxr_show_summ, (void *) &tym_desc, "Display a summary of line states" },
+    { MTAB_XTD|MTAB_VDV|MTAB_NMO, 1, "CONNECTIONS", NULL,
+        NULL, &tmxr_show_cstat, (void *) &tym_desc, "Display current connections" },
+    { MTAB_XTD|MTAB_VDV|MTAB_NMO, 0, "STATISTICS", NULL,
+        NULL, &tmxr_show_cstat, (void *) &tym_desc, "Display multiplexer statistics" },
+    { 0 }
+};
+
+/* Simulator debug controls */
+static DEBTAB tym_debug[] = {
+    {"CMD", DEBUG_CMD, "Show command execution to devices"},
+    {"DATA", DEBUG_DATA, "Show data transfers"},
+    {"DETAIL", DEBUG_DETAIL, "Show details about device"},
+    {"EXP", DEBUG_EXP, "Show exception information"},
+    {"IRQ", DEBUG_IRQ, "Show IRQ requests"},
+    {0, 0}
+};
+
+static int tym_host = 0;
+static int tym_base = BASE;
+static int tym_size = SIZE;
+static uint64 tym_key = KEY;
+static int output_port;
+static int output_count;
+
+static REG tym_reg[] = {
+    { ORDATA(HOST, tym_host, 16) },
+    { ORDATA(BASE, tym_base, 22) },
+    { ORDATA(SIZE, tym_size, 18) },
+    { ORDATA(KEY, tym_key, 36) },
+    { ORDATA(PORTS, tym_desc.lines, 8) },
+    { 0 }
+};
+
+DEVICE tym_dev = {
+    "TYM", tym_unit, tym_reg, tym_mod,
+    4, 8, 0, 1, 8, 36,
+    NULL, NULL, &tym_reset, NULL, &tym_attach, &tym_detach,
+    NULL, DEV_DISABLE | DEV_DIS | DEV_DEBUG, 0, tym_debug,
+    NULL, NULL, NULL, NULL, NULL, &tym_description
+};
+
+static t_stat tym_reset(DEVICE *dptr)
+{
+    int i;
+    if (tym_unit[0].flags & UNIT_ATT) {
+        sim_activate(&tym_unit[2], 1000);
+        sim_activate(&tym_unit[3], 1000);
+    } else {
+        sim_cancel(&tym_unit[0]);
+        sim_cancel(&tym_unit[1]);
+        sim_cancel(&tym_unit[2]);
+        sim_cancel(&tym_unit[3]);
+    }
+    return SCPE_OK;
+}
+
+static void block(void)
+{
+    int i;
+    for (i = 0; i < MAX_LINES; i++) {
+        tym_ldsc[i].rcve = 0;
+        tym_ldsc[i].xmte = 0;
+    }
+}
+
+static t_stat tym_attach(UNIT *uptr, CONST char *cptr)
+{
+    t_stat stat = tmxr_attach(&tym_desc, uptr, cptr);
+    block();
+    tym_reset(&tym_dev);
+    return stat;
+}
+
+static t_stat tym_detach(UNIT *uptr)
+{
+    t_stat stat = tmxr_detach(&tym_desc, uptr);
+    block();
+    tym_reset(&tym_dev);
+    return stat;
+}
+
+static uint64 word(int pointer, int base)
+{
+    int address = M[tym_base + base] >> 4;
+    address += M[tym_base + pointer];
+    return M[address];
+}
+
+static void next(int pointer, int size)
+{
+    uint64 modulo = M[tym_base + size] >> 4;
+    M[tym_base + pointer] = (M[tym_base + pointer] + 1) % modulo;
+}
+
+static void tym_input(uint64 data)
+{
+    int address = M[tym_base + IRNG] >> 4;
+    address += M[tym_base + IBP];
+    M[address] = data;
+}
+
+static unsigned room (int h, int t, int s)
+{
+    uint64 head = M[tym_base + h];
+    uint64 tail = M[tym_base + t];
+    uint64 size = M[tym_base + s] >> 4;
+    return size - (head - tail) % size;
+}
+
+static void send_word(int type, int port, int data1, int data2)
+{
+    uint64 data;
+    sim_debug(DEBUG_DETAIL, &tym_dev,
+               "Input from base: %03o %03o %03o %03o\n",
+               type, port, data1, data2);
+    /* The input ring buffer must have at least one word free. */
+    if (room (IBP, IHP, ISIZ) <= 1)
+        return;
+    data = (uint64)type << 28;
+    data |= (uint64)port << 20;
+    data |= (uint64)data1 << 12;
+    data |= (uint64)data2 << 4;
+    tym_input(data);
+    next(IBP, ISIZ);
+}
+
+static void send_character(int port, int c)
+{
+    sim_debug(DEBUG_DATA, &tym_dev, "Base: send port %d %03o '%c'.\n",
+               port, c, c);
+    send_word(TYMBAS_DATA | 1, port, c, 0);
+}
+
+static void send_string(int port, const char *string)
+{
+    int n = strlen(string);
+    int m;
+
+    for (;;) {
+        if (n <= 0)
+            return;
+        else if (n == 1) {
+            send_character(port, string[0]);
+            return;
+        }
+
+        m = n > 0177 ? 0177 : n;
+        n -= m;
+        send_word(TYMBAS_DATA | m, port, string[0], string[1]);
+        string += 2;
+        m -= 2;
+        while (m > 0) {
+            send_word(string[0], string[1], string[2], string[3]);
+            string += 4;
+            m -= 4;
+        }
+    }
+}
+
+static void send_login(int port)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "Base: send login %d.\n", port);
+    send_word(TYMBAS_LOG, port, 0, 0);
+    /* This isn't right, but good enough for now. */
+    send_string(port, ".....USER\r");
+}
+
+static void send_zap(int port)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "Base: send zap %d.\n", port);
+    send_word(TYMBAS_ZAP, port, 0, 0);
+}
+
+static void send_orange (int port)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "Base: send orange ball %d.\n", port);
+    send_word(TYMBAS_ORG, port, 0, 0);
+}
+
+static void recv_ans(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "system is answering\n");
+    sim_activate(&tym_unit[0], 1000);
+}
+
+static void recv_sht(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "system is up but shut\n");
+}
+
+static void recv_crs(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "sender is crashed\n");
+}
+
+static void recv_die(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "recipient should crash\n");
+}
+
+static void recv_nsp(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "base taken over by new supervisor\n");
+}
+
+static void recv_log(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "login\n");
+    //next 4 data chrs are the info about terminal type, and port or
+    //origin, then name, etc.
+}
+
+static void recv_aux(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "supervisor response to establishing auxillary circuit\n");
+}
+
+static void recv_nop(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " backpressure on\n");
+}
+
+static void recv_oup(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " backpressure off\n");
+}
+
+static void recv_gob(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " character gobbler\n");
+}
+
+static void recv_zap(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, "Zap circuit, port %d\n", port);
+    tmxr_reset_ln (&tym_ldsc[port]);
+    tym_ldsc[port].rcve = 0;
+    tym_ldsc[port].xmte = 0;
+}
+
+static void recv_edc(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " enter defered echo mode\n");
+}
+
+static void recv_ldc(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " leave deferred echo mode\n");
+}
+
+static void recv_grn(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " green ball\n");
+}
+
+static void recv_red(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " red ball\n");
+}
+
+static void recv_yel(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " yellow ball\n");
+    send_orange (port);
+}
+
+static void recv_org(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " orange ball\n");
+}
+
+static void recv_hng(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " hang character - not used\n");
+}
+
+static void recv_etm(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " enter 2741 transparent mode\n");
+}
+
+static void recv_ltm(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " leave 2741 transparent mode\n");
+}
+
+static void recv_los(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " lost ball\n");
+    //data has been lost from buffers. the data filed may tell how
+    //many were lost
+}
+
+static void recv_sup(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " supervisor request(aux circuits)\n");
+}
+
+static void recv_sur(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " supervisor response(aux circuits)\n");
+}
+
+static void recv_axc(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " supervisor string character\n");
+}
+
+static void recv_tsp(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " test pattern probe\n");
+}
+
+static void recv_tsr(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " test pattern response\n");
+}
+
+static void recv_sad(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " host sad\n");
+}
+
+static void recv_ecn(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " echo on\n");
+}
+
+static void recv_ecf(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " echo off\n");
+}
+
+static void recv_tcs(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " term characteristics\n");
+    //first data byte indicates which characteristics second data byte
+    //indicates value to set to
+}
+
+static void recv_tcp(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " term characteristcs probe\n");
+    //data byte indicates which terminal characteristic were requested
+}
+
+static void recv_tcr(int port, int subtype, int data)
+{
+    sim_debug(DEBUG_CMD, &tym_dev, " term characteristcs response\n");
+    //data is just like tcs, comes in response to a probe; also is
+    //reflected by remote when terminal characteristics are sent
+}
+
+static void recv_hsi(int port, int subtype, int data)
+{
+    tym_host = (subtype << 8) | data;
+    sim_debug(DEBUG_CMD, &tym_dev, "Host number %06o, %d ports\n",
+              tym_host, port);
+    /* Close ports above the host-annonuced maximum. */
+    tym_desc.lines = port;
+    if (tym_desc.lines > MAX_LINES)
+        tym_desc.lines = MAX_LINES;
+    for (port = tym_desc.lines; port < MAX_LINES; port++)
+        tmxr_reset_ln (&tym_ldsc[port]);
+    sim_activate(&tym_unit[0], 1000);
+}
+
+typedef void (*msgfn) (int, int, int);
+static msgfn output[] = {
+    NULL,
+    recv_ans,
+    recv_sht,
+    recv_crs,
+    recv_die,
+    recv_nsp,
+    recv_log,
+    recv_aux,
+    recv_nop,
+    recv_oup,
+    recv_gob,
+    recv_zap,
+    recv_edc,
+    recv_ldc,
+    recv_grn,
+    recv_red,
+    recv_yel,
+    recv_org,
+    recv_hng,
+    recv_etm,
+    recv_ltm,
+    recv_los,
+    recv_sup,
+    recv_sur,
+    recv_axc,
+    recv_tsp,
+    recv_tsr,
+    recv_sad,
+    recv_ecn,
+    recv_ecf,
+    recv_tcs,
+    recv_tcp,
+    recv_tcr,
+    recv_hsi
+};
+
+static void output_data(int port, int n)
+{
+    uint64 data;
+    int i = 2, c;
+
+    sim_debug(DEBUG_DATA, &tym_dev,
+               "Output from host: %d characters to port %d\n", n, port);
+
+    data = word(OBP, ORNG) << 16; /* Discard header. */
+    goto start;
+
+    while (n > 0) {
+        data = word(OBP, ORNG);
+    start:
+        for (; i < 4 && n > 0; i++, n--) {
+            c = data >> 28;
+            c &= 0177;
+            data <<= 8;
+            sim_debug(DEBUG_DATA, &tym_dev,
+                      "Host: send port %d %03o '%c'.\n", port, c, c);
+            tmxr_putc_ln(&tym_ldsc[port], c);
+            tmxr_poll_tx(&tym_desc);
+        }
+        i = 0;
+        next(OBP, OSIZ);
+    }
+}
+
+static void tym_output(void)
+{
+    int type, port, subtype, data;
+    while (M[tym_base + OBP] != M[tym_base + OHP]) {
+        sim_debug(DEBUG_DETAIL, &tym_dev, "Output from host: %llu %012llo\n",
+                   M[tym_base + OBP], word(OBP, ORNG));
+        type = word(OBP, ORNG) >> 28;
+        port = (word(OBP, ORNG) >> 20) & 0377;
+        subtype = (word(OBP, ORNG) >> 12) & 0377;
+        data = (word(OBP, ORNG) >> 4) & 0377;
+        sim_debug(DEBUG_DETAIL, &tym_dev,
+                   "Type %03o, port %03o, subtype %03o, data %03o\n",
+                   type, port, subtype, data);
+        if (type >= 1 && type <= 41) {
+            output[type] (port, subtype, data);
+            next(OBP, OSIZ);
+        } else if (type & 0200)
+            output_data(port, type & 0177);
+    }
+}
+
+static uint64 lock = ~0ULL;
+static uint64 dump = ~0ULL;
+static uint64 irng = ~0ULL;
+static uint64 isiz = ~0ULL;
+static uint64 ihp = ~0ULL;
+static uint64 ibp = ~0ULL;
+static uint64 orng = ~0ULL;
+static uint64 osiz = ~0ULL;
+static uint64 ohp = ~0ULL;
+static uint64 obp = ~0ULL;
+static uint64 bcrsh = ~0ULL;
+static uint64 hcrsh = ~0ULL;
+
+static void check(const char *name, int offset, uint64 *value)
+{
+    uint64 x = M[tym_base + offset];
+    if (x != *value) {
+        sim_debug(DEBUG_DETAIL, &tym_dev, "%s: %012llo\n", name, x);
+        *value = x;
+    }
+}
+
+static t_stat tym_interface_srv(UNIT *uptr)
+{
+    check("Dump location", DUMP, &dump);
+    check("Input ring location", IRNG, &irng);
+    check("Input ring size", ISIZ, &isiz);
+    check("Host input pointer", IHP, &ihp);
+    check("Base input pointer", IBP, &ibp);
+    check("Output ring location", ORNG, &orng);
+    check("Output ring size", OSIZ, &osiz);
+    check("Host output pointer", OHP, &ohp);
+    check("Base output pointer", OBP, &obp);
+    check("Base crash reason", BCRSH, &bcrsh);
+    check("Host crash reason", HCRSH, &hcrsh);
+
+    if (ohp != obp)
+        tym_output();
+
+    sim_activate_after(&tym_unit[2], 1000);
+    return SCPE_OK;
+}
+
+static t_stat tym_alive_srv(UNIT *uptr)
+{
+    if (M[tym_base + LOCK] == tym_key) {
+        M[tym_base + LOCK] = 1;
+    }
+
+    sim_activate_after(&tym_unit[3], 500000);
+    return SCPE_OK;
+}
+
+static t_stat tym_input_srv(UNIT *uptr)
+{
+    int32 ch;
+    int i;
+
+    if (room (IBP, IHP, ISIZ) > 1) {
+        i = tmxr_poll_conn(&tym_desc);
+        if (i >= 0) {
+            tym_ldsc[i].rcve = 1;
+            tym_ldsc[i].xmte = 1;
+            send_login(i);
+        }
+    }
+
+    tmxr_poll_rx(&tym_desc);
+
+    for (i = 0; i < tym_desc.lines; i++) {
+        if (tym_ldsc[i].xmte && tym_ldsc[i].conn == 0) {
+            tmxr_reset_ln (&tym_ldsc[i]);
+            tym_ldsc[i].rcve = 0;
+            tym_ldsc[i].xmte = 0;
+            send_zap(i);
+            continue;
+        }
+
+        /* The input ring buffer must have at least one word free. */
+        if (room (IBP, IHP, ISIZ) <= 1)
+            continue;
+
+        ch = tmxr_getc_ln(&tym_ldsc[i]);
+        if (ch & TMXR_VALID)
+            send_character(i, ch & 0377);
+    }
+
+    sim_activate(&tym_unit[0], 1000);
+    return SCPE_OK;
+}
+
+static t_stat tym_output_srv(UNIT *uptr)
+{
+    uint64 data;
+    int i, c;
+
+    if (!tmxr_txdone_ln(&tym_ldsc[output_port])) {
+        sim_activate(&tym_unit[1], 1000);
+        return SCPE_OK;
+    }
+
+    data = word(OBP, ORNG);
+
+    c = data >> 28;
+    c &= 0177;
+    data <<= 8;
+    sim_debug(DEBUG_DATA, &tym_dev,
+               "Host: send port %d %03o '%c'.\n", output_port, c, c);
+    if (tmxr_putc_ln(&tym_ldsc[output_port], c) == SCPE_STALL)
+        return SCPE_OK;
+
+    next(OBP, OSIZ);
+    if (output_count > 0)
+        sim_activate(&tym_unit[1], 1000);
+    return SCPE_OK;
+}
+
+static const char *tym_description(DEVICE *dptr)
+{
+    return "Tymnet interface";
+}
+#endif
diff --git a/makefile b/makefile
index 1d5033b..a99a05b 100644
--- a/makefile
+++ b/makefile
@@ -2139,7 +2139,7 @@ KI10 = ${KI10D}/kx10_cpu.c ${KI10D}/kx10_sys.c ${KI10D}/kx10_df.c \
 	${KI10D}/kx10_dt.c ${KI10D}/kx10_dk.c ${KI10D}/kx10_cr.c \
 	${KI10D}/kx10_cp.c ${KI10D}/kx10_tu.c ${KI10D}/kx10_rs.c \
 	${KI10D}/kx10_imp.c ${KI10D}/kx10_dpy.c ${KI10D}/kx10_disk.c \
-	${KI10D}/kx10_ddc.c ${DISPLAYL} ${DISPLAY340}
+	${KI10D}/kx10_ddc.c ${KI10D}/kx10_tym.c ${DISPLAYL} ${DISPLAY340}
 KI10_OPT = -DKI=1 -DUSE_INT64 -I ${KI10D} -DUSE_SIM_CARD ${NETWORK_OPT} ${DISPLAY_OPT} ${KI10_DISPLAY_OPT}
 ifneq (${PANDA_LIGHTS},)
 # ONLY for Panda display.