github.com/simh.simh
1
0
Fork 0
mirror of https://github.com/simh/simh.git synced 2026-01-11 23:52:58 +00:00
Code Releases Activity

I1401: Reverted tape mark behaviour as revision was wrong

Browse Source 
I talked to Van Snyder and he told me about this "fix" he wanted
introduced in SimH i1401. The fix was needed to get a program running.
The program not working was likely due to a transcription error, not
the emulator. That "fix" thus introduced a bug, this change fixes it..

The bug: Currently SimH i1401 doesn't deposit a group mark in core
memory after reading a tape mark. It only deposits the tape mark.
This is wrong. The tape mark should be followed by a group mark.
This commit is contained in:
Prince-Stolas 2025-08-15 17:06:51 -10:00 committed by Mark Pizzolato
parent caea0c0970
commit ea3aaf7724
1 changed files with 1 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
I1401/i1401_mt.c
View File

@ -25,6 +25,7 @@
mt 7-track magtape
15-Aug-25 VRS Reverted tape mark behaviour as revision was wrong (Van Snyder)
26-Mar-22 RMS Added extra case points for new MTSE definitions
20-Oct-16 RMS Must call sim_tape_attach to use library (Mark Pizzolato)
03-Sep-13 RMS Read TMK does not write GM+WM to memory
@ -346,8 +347,6 @@ switch (mod) {
return STOP_WRAP;
}
}
if (st == MTSE_TMK) /* if TMK, no GM+WM */
break;
if (M[BS] != (BCD_GRPMRK + WM)) { /* not GM+WM at end? */
if (flag & MD_WM) /* LCA: clear WM */
M[BS] = BCD_GRPMRK;