n to t-t t:S rt t1 o n rt .... o t:S ... I ... ..... r: • GR 1 I [GR 2 1\ FOR SVC 76
------ SVC VMES1AT VMBLOK GR 15
A (CALLED ROUTINE) I I SVC Interrupt ----------Process---------.., If PROBLEM MODE • And ADSTOP SVC, simulate 'ADSTOP' to
virtual machine • And an SVC 76, verify the parameters and call DMKVER to build the error record." • And virtual machine IS In extended .., mode and/or Pa!je 0 is not in storage, reflect interrupt to virtual machine • Otherwise, fetch Page 0, move CP PSW to virtual SVCOPSW, and move SVCNPSW to the CP PSW • If supervisor mode, run user-LPSW If SVC 0 (Impossible condition or fatal error), dump the machine If SVC 8 (Link Requestl. e pass control from one module to another If SVC 12 (Return Request), return control to calling module If SVC 16, release Save Area CIt If SVC 20, !Jet next save area for calling module If SVC 24, switch processing to
main processor OUTPUT VMBLOK User Page PSA SVC OLD PSW EJ ---- RUNPSW SVC NEW PSW V E=J - return I /address and SAVE AREA OF CALLING MODULE • If DMKSVC determines that the SVC 76 W parameters are valid, It calls DMKVER to build the
error record. If the parameters are not valid or if
DMKVER cannot build the error record, DMKSVC reflects the SVC back to the virtual machtne. If the
error record is recorded, DMKVER gives control to
the dispatcher with the user's running sta1Us set to
return to the next sequential instruction following the SVC 76. O A new save area is acquired
: and passed on. The caller's addressability
register (R 121. the save area address (R 13), and the return address (SVCOPSW) are
saved in the new save area. A Control is returned to module issuing .1 SVC lEi, rather than to calling module
as in SVC 12. e Return is to module issuing SVC 20. e Return is on other processor to
module issuing SVC 24 .

.... I ..,. .... I.Q (X) = 11 (I) .... txt U'1 =- . ca =- bI1 " H W c+ ...., (I) 0 11 U2 = J» Io.cS en ..... c+ .... (I) = • c+ (1) tat 11 0 11 I.Q = ..,. t'Ij n c+ J» ::x: ::s J» p, = P, I'd ..... 11 .... 0 = t:f \Q ..... d) • t:j (I) c+ (I) 11 • ..,. ts Pt c+ ..,. 0 ts I I ca 0 ..... CS • (I) .... External Interrupt PrOC8H--------------------------------------, OUTPUT ---------. If TOO clock comparator interrupt • unchain from TOO clock comparator VMBLOK • queue the related TRQBLOK PSA (prefix Storage Area) VMBLOK VMTERM RDEVBLOK I • place on dispatch queue • set new clock comparator request ............. VMGPRS If CPU timer interrupt ------------ • flag running user to be dropped from queue
VMFPRS If a Timer interrupt • if supervisor mode, ignore • otherwise, save machine status: VMOSTAT (for
operator) If interrupt from the Console Interrupt Button (External) • • Set the disconnect flag in VMBLOK • Halt any outstanding I/O • Clear any outstanding console requests • If the running user was not interrupted,
resume where left off by LPSW of External old PSW ..... -< External interrupt from control panel is used to disconnect
the system operator's terminal. The system operator may
reconnect at any other terminal via the LOGON command. ------ VMBLOK VMOSTAT X'10' VMTERM X'OO'