diff --git a/BESM6/besm6_disk.c b/BESM6/besm6_disk.c
index b5febae9..40e5065c 100644
--- a/BESM6/besm6_disk.c
+++ b/BESM6/besm6_disk.c
@@ -28,6 +28,7 @@
  * authorization from Leonid Broukhis and Serge Vakulenko.
  */
 #include "besm6_defs.h"
+#include <ctype.h>
 
 /*
  * Управляющее слово обмена с магнитным диском.
@@ -48,6 +49,11 @@
  */
 #define STATUS_GOOD     014000400
 
+/*
+ * Total size of a disk in blocks, including hidden blocks
+ */
+#define DISK_TOTBLK     01767
+
 /*
  * Параметры обмена с внешним устройством.
  */
@@ -160,10 +166,57 @@ t_stat disk_reset (DEVICE *dptr)
 t_stat disk_attach (UNIT *u, char *cptr)
 {
     t_stat s;
+    int32 saved_switches = sim_switches;
+    sim_switches |= SWMASK ('E');
 
-    s = attach_unit (u, cptr);
-    if (s != SCPE_OK)
-        return s;
+    while (1) {
+        s = attach_unit (u, cptr);
+        if ((s == SCPE_OK) && (sim_switches & SWMASK ('N'))) {
+            t_value control[4];  /* block (zone) number, key, userid, checksum */
+            int diskno, blkno, word;
+            char *pos;
+            /* Using the rightmost sequence of digits within the filename
+             * as a volume number, e.g. "/var/tmp/besm6/2052.bin" -> 2052
+             */
+            pos = cptr + strlen(cptr);
+            while (pos > cptr && !isdigit(*--pos));
+            while (pos > cptr && isdigit(*pos)) --pos;
+            if (!isdigit(*pos)) ++pos;
+            diskno = atoi(pos);
+            if (diskno < 2048 || diskno > 4095) {
+                if (diskno == 0)
+                    sim_printf ("%s: filename must contain volume number 2048..4095\n", sim_uname(u));
+                else
+                    sim_printf ("%s: disk volume %d from filename %s invalid (must be 2048..4095)\n",
+                                sim_uname (u), diskno, cptr);
+                /* unlink (cptr); ??? */
+                return SCPE_ARG;
+            }
+            if (!sim_quiet && !(sim_switches & SWMASK ('Q')))
+                sim_printf ("%s: formatting disk volume %d\n", sim_uname (u), diskno);
+
+            control[1] = SET_CONVOL(0, CONVOL_NUMBER);
+            control[2] = SET_CONVOL(0, CONVOL_NUMBER);
+            control[3] = SET_CONVOL(0, CONVOL_NUMBER);
+
+            control[1] |= 01370707LL << 24;    /* Magic mark */
+            control[1] |= diskno << 12;
+
+            for (blkno = 0; blkno < DISK_TOTBLK; ++blkno) {
+                control[0] = SET_CONVOL((t_value)(2*blkno) << 36, CONVOL_NUMBER);
+                fwrite(control, sizeof(t_value), 4, u->fileref);
+                control[0] = SET_CONVOL((t_value)(2*blkno+1) << 36, CONVOL_NUMBER);
+                fwrite(control, sizeof(t_value), 4, u->fileref);
+                for (word = 0; word < 02000; ++word) {
+                    fwrite(control+2, sizeof(t_value), 1, u->fileref);
+                }
+            }
+            return SCPE_OK;
+        }
+        if (saved_switches & SWMASK ('E'))
+            return s;
+        sim_switches |= SWMASK ('N');
+    }
     return SCPE_OK;
 }
 
diff --git a/BESM6/besm6_tty.c b/BESM6/besm6_tty.c
index ad80ec56..f260fe8b 100644
--- a/BESM6/besm6_tty.c
+++ b/BESM6/besm6_tty.c
@@ -617,7 +617,7 @@ void tt_print()
  */
 static int unicode_to_koi7 (unsigned val)
 {
-    if ('_' <= val) return val;
+    if (val <= '_') return val;
     else if ('a' <= val && val <= 'z') return val + 'Z' - 'z';
     else switch (val) {
         case 0x007f:              return 0x7f;
diff --git a/BESM6/dispak.ini b/BESM6/dispak.ini
index d182d028..c812b662 100644
--- a/BESM6/dispak.ini
+++ b/BESM6/dispak.ini
@@ -16,13 +16,12 @@ attach drum1 drum2x.bin
 ;
 ; Создаем рабочий диск.
 ;
-! ./formatdisk 2052 > 2052.bin
+attach -n disk6 2052.bin
 
 ;
 ; Подключаем диски.
 ;
 attach -e disk7 sbor2053.bin
-attach -e disk6 2052.bin
 attach -e disk5 krab2063.bin
 attach -e disk0 sbor2048.bin
 attach -e disk1 svs2048.bin
diff --git a/BESM6/formatdisk.c b/BESM6/formatdisk.c
deleted file mode 100644
index b72c7b86..00000000
--- a/BESM6/formatdisk.c
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * formatdisk.c - A utility to produce blank BESM-6 disk images.
- *
- * Copyright (c) 2014 Leonid Broukhis
- *
- * 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
- * SERGE VAKULENKO OR LEONID BROUKHIS 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 Leonid Broukhis or
- * Serge Vakulenko shall not be used in advertising or otherwise to promote
- * the sale, use or other dealings in this Software without prior written
- * authorization from Leonid Broukhis and Serge Vakulenko.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include "besm6_defs.h"
-
-#define TOTBLK 01767
-
-int main(int argc, char ** argv) {
-    t_value control[4];  /* block (zone) number, key, userid, checksum */
-    int diskno, blkno, word;
-
-    if (argc != 2 || (diskno = atoi(argv[1])) < 2048 || diskno > 4095) {
-        fprintf(stderr, "Usage: formatdisk NNNN > diskNNNN.bin, where 2048 <= NNNN <= 4095\n");
-        exit(1);
-    }
-
-    control[1] = SET_CONVOL(0, CONVOL_NUMBER);
-    control[2] = SET_CONVOL(0, CONVOL_NUMBER);
-    control[3] = SET_CONVOL(0, CONVOL_NUMBER);
-
-    control[1] |= 01370707LL << 24;    /* Magic */
-    control[1] |= diskno << 12;
-
-    for (blkno = 0; blkno < TOTBLK; ++blkno) {
-        control[0] = SET_CONVOL((t_value)(2*blkno) << 36, CONVOL_NUMBER);
-        fwrite(control, sizeof(t_value), 4, stdout);
-        control[0] = SET_CONVOL((t_value)(2*blkno+1) << 36, CONVOL_NUMBER);
-        fwrite(control, sizeof(t_value), 4, stdout);
-        for (word = 0; word < 02000; ++word) {
-            fwrite(control+2, sizeof(t_value), 1, stdout);
-        }
-    }
-    exit(0);
-}
diff --git a/makefile b/makefile
index 9e92b82c..0ac02237 100644
--- a/makefile
+++ b/makefile
@@ -1171,8 +1171,6 @@ BESM6 = ${BESM6D}/besm6_cpu.c ${BESM6D}/besm6_sys.c ${BESM6D}/besm6_mmu.c \
 	${BESM6D}/besm6_tty.c ${BESM6D}/besm6_panel.c ${BESM6D}/besm6_printer.c \
 	${BESM6D}/besm6_punch.c
 
-FORMATDISK = ${BESM6D}/formatdisk.c
-
 ifeq (,${VIDEO_LDFLAGS})
 	BESM6_OPT = -I ${BESM6D} -DUSE_INT64 
 else ifneq (,$(and $(findstring SDL2,${VIDEO_LDFLAGS}),$(call find_include,SDL2/SDL_ttf),$(call find_lib,SDL2_ttf)))
@@ -1486,16 +1484,12 @@ ${BIN}ssem${EXE} : ${SSEM} ${SIM}
 	${MKDIRBIN}
 	${CC} ${SSEM} ${SIM} ${SSEM_OPT} $(CC_OUTSPEC) ${LDFLAGS}
 
-besm6 : ${BIN}besm6${EXE} ${BIN}formatdisk${EXE}
+besm6 : ${BIN}besm6${EXE}
 
 ${BIN}besm6${EXE} : ${BESM6} ${SIM}
 	${MKDIRBIN}
 	${CC} ${BESM6} ${SIM} ${BESM6_OPT} $(CC_OUTSPEC) ${LDFLAGS}
 
-${BIN}formatdisk${EXE} : ${FORMATDISK}
-	${MKDIRBIN}
-	${CC} ${FORMATDISK} ${BESM6_OPT} $(CC_OUTSPEC)
-
 sigma : ${BIN}sigma${EXE}
 
 ${BIN}sigma${EXE} : ${SIGMA} ${SIM}