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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Rob,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Simh device wait units are instructions. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Usually a device has no specific knowledge about the significance of wall time vs instructions. To help solve this problem some methods exist to specify wait times which correlate with the simulated machine’s clock ticks which are dynamically calibrated to produce a number of instructions per unit of time (clock tick). Devices usually behave well if wait units are aligned on clock ticks and doing this helps produce better ‘idling’ behavior. A device which wants to wake up on every simulated clock tick would code the following:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas;color:blue'>extern</span><span style='font-size:9.5pt;font-family:Consolas'> int32 tmxr_poll; <span style='color:green'>/* calibrated delay */</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> sim_activate (uptr, clk_cosched (tmxr_poll)); <span style='color:green'>/* reactivate */</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Good Luck,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Mark<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> simh-bounces@trailing-edge.com [mailto:simh-bounces@trailing-edge.com] <b>On Behalf Of </b>Rob Jarratt<br><b>Sent:</b> Sunday, October 07, 2012 10:05 AM<br><b>To:</b> simh@trailing-edge.com<br><b>Subject:</b> [Simh] Device Timing Question<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p><span lang=EN-GB style='font-family:"Calibri","sans-serif"'>The device I am emulating appears to be running too fast for the driver that uses it and I need to get to grips with device timing in SIMH.</span><span lang=EN-GB> </span><span lang=EN-GB style='font-family:"Calibri","sans-serif"'>I have never fully understood the use of sim_activate, in particular what are the units of time that are passed to this routine?</span><o:p></o:p></p><p><span lang=EN-GB style='font-family:"Calibri","sans-serif"'>Thanks</span><o:p></o:p></p><p><span lang=EN-GB style='font-family:"Calibri","sans-serif"'>Rob</span><o:p></o:p></p></div></div></body></html>