Yes, but that is not an adequate reason to add the SysRq key when the PC-AT came out, for 3270 emulators had already picked a substitute keystroke for the 3270 SysReq key. If that had been the justification, it would have been much saner to add F11, F12, PA1, and PA2, far more important, and far more often used, whereas, in actual fact, F11 and F12 were not added to PCs (except custom-made 3270-PC devices) until two years later, and PA1 and PA2 have to be simulated to this day. An adequate reason, and one that matches well with the actual implementation of the SysRq key in BIOS, is that it was intended for calling up a task manager or similar function on a future, protected-mode operating system. (OS/2 was more than three years off, and the inept clone of OS/2 variously known over the years as “Windows NT”, “Windows 2000”, and “Windows XP”, more than eight, but IBM promised that a protected-mode operating system would be available when they announced the AT.) For reasons unknown to me (but probably having to do with Microsoft stupidity), Ctrl-Esc was chosen instead.