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<p class="MsoNormal">I am building a replica RK05 disk drive with working switches and panel lamps.</p>
<p class="MsoNormal">This will be an add-on to the PiDP-11/70, giving the user even more the look</p>
<p class="MsoNormal">and feel of operating a PDP-11 system <span style="font-family:"Segoe UI Emoji",sans-serif">
😊</span> The RK05 drive is constructed at the</p>
<p class="MsoNormal">same scale dimensions as Oscar's PiDP-11/70 and has a front door with lock</p>
<p class="MsoNormal">mechanism just like the real RK05. A real RK05 disk cartridge is 3D scanned</p>
<p class="MsoNormal">and will be (scaled) 3D printed. Inside that disk cartridge is a USB stick on</p>
<p class="MsoNormal">which 7 virtual RK05 "disk" container files can be stored. Jumper setting in</p>
<p class="MsoNormal">the cartridge selects which container file is actually "mounted" when the<br>
cartrdige is mounted in the drive.</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So far for the introduction <span style="font-family:"Segoe UI Emoji",sans-serif">
😊</span></p>
<p class="MsoNormal">To make this setup work I have made changes to scp.c, scp.h, pdp11_cpu.c,</p>
<p class="MsoNormal">pdp11_rk.c and the makefile, and added a few files (drive "behavior" and USB</p>
<p class="MsoNormal">stick handling).</p>
<p class="MsoNormal">All indicator lamps seem to behave as on the real RK05 drive ... however,</p>
<p class="MsoNormal">when I do .FORMAT RK0: (I am using RT-11) this command always ends with</p>
<p class="MsoNormal">turning on the FAULT indicator. I have added print statements to the original</p>
<p class="MsoNormal">SIMH distribution in pdp11_rk.c to show the problem (so no "rubbish of mine</p>
<p class="MsoNormal">interference").</p>
<p class="MsoNormal">This is what I see:</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">PDP-11 simulator V4.0-0 Current git commit id: 0de9b628<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">sim> set rl rl02<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">sim> att rl0 rt-work.dsk<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">RL0: 'rt-work.dsk' Contains RT11 partitions<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">1 valid partition, Type: V05, Sectors On Disk: 10210<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">sim> att rk0 rk.dsk<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">RK: creating new file<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">sim> boot rl0<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">RT-11FB V5.03<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">.dir rk0:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">?DIR-F-Invalid directory<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">.format rk0:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">RK0:/FORMAT-Are you sure? Y<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""> pdp11_rk.c :: in rk_go() cyl >= RK_NUMCY<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""> pdp11_rk.c :: rk_set_done() called with error 64<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">?FORMAT-I-Formatting complete<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">.init rk0:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">RK0:/Initialzie; Are you sure? Y<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">.dir rk0:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">0 Files, 0 Blocks<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">4762 Free blocks<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">.<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As you can see from the printed debug statements, in the function rk_go()</p>
<p class="MsoNormal">the cylinder number goes higher than the maximum number of cylinders</p>
<p class="MsoNormal">possible on an RK05. Then, the function rk_set_done() is called with the</p>
<p class="MsoNormal">variable "error" holding RKER_NXC (64 decimal == 000100, octal == RKER_NXC)<br>
==> turns on the FAULT indicator.</p>
<p class="MsoNormal">SIMH does not generate an error, all is OK, as is on the real PDP-11 / RK05.</p>
<p class="MsoNormal">For now, I "solved" this by adding "if (error != RKER_NXC)", but that</p>
<p class="MsoNormal">will exclude all "non-existing cylinder" errors, not only the error that</p>
<p class="MsoNormal">is generated at the end of the FORMAT RK0: command.</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is this incorrect behavior in SIMH, simulating the RK05? I don't believe</p>
<p class="MsoNormal">that, so is the RKER_NXC handled in the RK.SYS driver or in RT11 in case of</p>
<p class="MsoNormal">the execution of the FORMAT command?</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,</p>
<p class="MsoNormal">Henk</p>
<p class="MsoNormal"><a href="http://www.pdp-11.nl">www.pdp-11.nl</a> <o:p></o:p></p>
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