wfjm.w11/doc/w11a_diff_70_stklim_rset.md

Known differences between w11a and KB11-C (11/70)

Stack limit checks done independent of register set

The 11/70 does a stack limit check (yellow or red zone) when

• in kernel mode
• register set 0 active
• a write via SP with address modes 1, 2, 4, 6 is done, thus (sp), (sp)+, -(sp), nn(sp)

The fact that the check is only performed when register set 0 is active is only mentioned as a marginal note in the Technical Manual and can easily be checked in the Schematics.

The w11 does stack limit checks independent of the register set selection in PSW bit 11.