Tape image
(gdb) r
Starting program: /tmp/open-simh-simh-a1f57fa/BIN/pdp8
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
PDP-8 simulator Open SIMH V4.1-0 Current simh git commit id: a1f57fa
[Detaching after vfork from child process 1703327]
[Detaching after vfork from child process 1703328]
[Detaching after vfork from child process 1703329]
[Detaching after vfork from child process 1703332]
[Detaching after vfork from child process 1703333]
[Detaching after vfork from child process 1703334]
[Detaching after vfork from child process 1703335]
sim> set dt dis
sim> set td en
sim> att td0 cogo-8.tu56
TD0: 12b format, buffering file in memory
sim> bo td0
%SIM-INFO: SIGINT will be delivered to your debugger when the ^F character is entered
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7c166ee in __memcmp_avx2_movbe () from /lib64/libc.so.6
?2004hMissing rpms, try: dnf --enablerepo='debug' install sdl2-compat-debuginfo-2.32.70-1.fc43.x86_64 glibc-debuginfo-2.42-13.fc43.x86_64 pcre2-debuginfo-10.47-1.fc43.x86_64 libedit-debuginfo-3.1-58.20260512cvs.fc43.x86_64 ncurses-libs-debuginfo-6.5-7.20250614.fc43.x86_64 libpng-debuginfo-1.6.58-1.fc43.x86_64 zlib-ng-compat-debuginfo-2.3.3-2.fc43.x86_64 SDL3-debuginfo-3.4.12-1.fc43.x86_64
?2004h(gdb) bt
#0000x00007ffff7c166ee in __memcmp_avx2_movbe () from /lib64/libc.so.6
#1 0x000000000042d94d in detach_unit (uptr=0x4e83e0 <td_unit>) at ./scp.c:8441
#2 0x0000000000411186 in td_svc (uptr=0x4e83e0 <td_unit>)
at ./PDP8/pdp8_td.c:506
#3 0x0000000000437b98 in sim_process_event () at ./scp.c:11987
#4 0x0000000000401625 in sim_instr () at ./PDP8/pdp8_cpu.c:355
#5 0x0000000000431196 in run_cmd (flag=5, cptr=0x7fffffff4566 "")
at ./scp.c:9367
#6 0x000000000041bc72 in process_stdin_commands (stat=0, argv=0x5b3380,
do_called=0) at ./scp.c:3065
#7 0x000000000041b853 in main (argc=1, argv=0x5b3380) at ./scp.c:2987
?2004h(gdb) up
#1000x000000000042d94d in detach_unit (uptr=0x4e83e0 <td_unit>) at ./scp.c:8441
8441 (memcmp (uptr->filebuf, uptr->filebuf2, (size_t)(SZ_D (dptr) * (uptr->capac / dptr->aincr))) != 0)) {
?2004h(gdb) p *uptr
$10=4{next = 0x0, action = 0x410f7c <td_svc>,
filename = 0x600820 "cogo-8.tu56", fileref = 0x5e93b0,
filebuf = 0x7ffff7a71010, filebuf2 = 0x0, hwmark = 190146, time = 0,
flags = 67349, dynflags = 0, capac = 190146, pos = 947328,
io_flush = 0x412063 <td_flush>, iostarttime = 0, buf = 0, wait = 0, u3 = 6,
u4 = 18101774, u5 = 0, u6 = 0, up7 = 0x0, up8 = 0x0, us9 = 0, us10 = 0,
disk_type = 0, tmxr = 0x0, recsize = 0, tape_eom = 0, cancel = 0x0,
usecs_remaining = 0, uname = 0x0, dptr = 0x4e8d40 <td_dev>, dctrl = 0}
filebuf2 null looks like a problem
Tape image
(gdb) r
Starting program: /tmp/open-simh-simh-a1f57fa/BIN/pdp8
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
PDP-8 simulator Open SIMH V4.1-0 Current simh git commit id: a1f57fa
[Detaching after vfork from child process 1703327]
[Detaching after vfork from child process 1703328]
[Detaching after vfork from child process 1703329]
[Detaching after vfork from child process 1703332]
[Detaching after vfork from child process 1703333]
[Detaching after vfork from child process 1703334]
[Detaching after vfork from child process 1703335]
sim> set dt dis
sim> set td en
sim> att td0 cogo-8.tu56
TD0: 12b format, buffering file in memory
sim> bo td0
%SIM-INFO: SIGINT will be delivered to your debugger when the ^F character is entered
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7c166ee in __memcmp_avx2_movbe () from /lib64/libc.so.6
?2004hMissing rpms, try: dnf --enablerepo='debug' install sdl2-compat-debuginfo-2.32.70-1.fc43.x86_64 glibc-debuginfo-2.42-13.fc43.x86_64 pcre2-debuginfo-10.47-1.fc43.x86_64 libedit-debuginfo-3.1-58.20260512cvs.fc43.x86_64 ncurses-libs-debuginfo-6.5-7.20250614.fc43.x86_64 libpng-debuginfo-1.6.58-1.fc43.x86_64 zlib-ng-compat-debuginfo-2.3.3-2.fc43.x86_64 SDL3-debuginfo-3.4.12-1.fc43.x86_64
?2004h(gdb) bt
#0000x00007ffff7c166ee in __memcmp_avx2_movbe () from /lib64/libc.so.6
#1 0x000000000042d94d in detach_unit (uptr=0x4e83e0 <td_unit>) at ./scp.c:8441
#2 0x0000000000411186 in td_svc (uptr=0x4e83e0 <td_unit>)
at ./PDP8/pdp8_td.c:506
#3 0x0000000000437b98 in sim_process_event () at ./scp.c:11987
#4 0x0000000000401625 in sim_instr () at ./PDP8/pdp8_cpu.c:355
#5 0x0000000000431196 in run_cmd (flag=5, cptr=0x7fffffff4566 "")
at ./scp.c:9367
#6 0x000000000041bc72 in process_stdin_commands (stat=0, argv=0x5b3380,
do_called=0) at ./scp.c:3065
#7 0x000000000041b853 in main (argc=1, argv=0x5b3380) at ./scp.c:2987
?2004h(gdb) up
#1000x000000000042d94d in detach_unit (uptr=0x4e83e0 <td_unit>) at ./scp.c:8441
8441 (memcmp (uptr->filebuf, uptr->filebuf2, (size_t)(SZ_D (dptr) * (uptr->capac / dptr->aincr))) != 0)) {
?2004h(gdb) p *uptr
$10=4{next = 0x0, action = 0x410f7c <td_svc>,
filename = 0x600820 "cogo-8.tu56", fileref = 0x5e93b0,
filebuf = 0x7ffff7a71010, filebuf2 = 0x0, hwmark = 190146, time = 0,
flags = 67349, dynflags = 0, capac = 190146, pos = 947328,
io_flush = 0x412063 <td_flush>, iostarttime = 0, buf = 0, wait = 0, u3 = 6,
u4 = 18101774, u5 = 0, u6 = 0, up7 = 0x0, up8 = 0x0, us9 = 0, us10 = 0,
disk_type = 0, tmxr = 0x0, recsize = 0, tape_eom = 0, cancel = 0x0,
usecs_remaining = 0, uname = 0x0, dptr = 0x4e8d40 <td_dev>, dctrl = 0}
filebuf2 null looks like a problem