[664] | 1 | <?php |
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| 2 | $seiten_id = 'ibm1130-blog'; |
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| 3 | $version = '$Id'; |
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| 4 | $titel = 'IBM 1130 Reparation Blog'; |
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| 5 | |
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| 6 | require '../../lib/technikum29.php'; |
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| 7 | ?> |
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| 8 | |
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[667] | 9 | <h2>IBM 1130 Reparation Blog, continuation</h2> |
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[664] | 10 | |
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[667] | 11 | <br> |
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| 12 | |
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| 13 | The beginning you'll find here <a href="/en/computer/ibm1130.php#blog-ibm"> <b>IBM-Blog, start</b> </a> |
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| 14 | <br><br> |
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| 15 | |
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| 16 | <b>7.6.2014:</b> The card 7432 we are looking for is only used in systems with a memory |
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| 17 | expansion. These mainframes are much rarer than the smaller IBM 1130 systems |
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| 18 | without the additional left enclosure. Therefore both, the card missing in |
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| 19 | out machine as well as its schematics have apparently not been preserved. |
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| 20 | Accordingly, we reverse-engineered the circuit diagram based on measurements |
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| 21 | on an existing card and rebuilt the card. Now the core memory of our IBM 1130 |
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| 22 | is working like a charm which is a significant milestone.<br><br> |
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| 23 | |
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| 24 | <div class="desc-left"> |
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| 25 | <a class="popup" href="/shared/photos/rechnertechnik/1130-reparatur.jpg"> |
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| 26 | <img src="/shared/photos/rechnertechnik/1130-reparatur.jpg" alt="1130 während der Reparatur" width="391" height="269" /></a> |
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| 27 | <p class="small">So it looks while repairing. Invisible: Measuring Park and many simultaneously opened Manuals.<br> |
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| 28 | Enlarge: click on picture!</p></div> |
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| 29 | |
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| 30 | <b>16.6.2014:</b> Giant leaps: After an intensive cleaning effort with adjustments following, |
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| 31 | the card reader IBM 1442 is now fully operational and we could successfully |
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| 32 | run the seven so-called "One-Card-Diagnostic" programs. This demonstrated |
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| 33 | that the CPU is at least basically operating (since these tests are quite |
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| 34 | simple in nature they can not detect subtle faults).<br> |
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| 35 | The next test involved the console printer: A working console printer is necessary to communicate |
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| 36 | with the machine - unfortunately, this test showed that the printer is still |
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| 37 | faulty. Currently, we suspect resinified oil as the culprit. <br><br> |
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| 38 | |
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| 39 | <b>31.08.2014:</b> We would like to thank the people from the "Verein fuer ein Museum |
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| 40 | der Lochkartentechnik", cosecans.ch, who donated a set of plug in cards |
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| 41 | for the IBM 1131 processor. Without these spares our repair attempts would be |
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| 42 | next to impossible due to the SLT technology.<br> |
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| 43 | Further tests showed that memory and CPU test run flawlessly but the |
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| 44 | keyboard/printer-test still fails.<br><br> |
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| 45 | |
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| 46 | <b>07.09.2014:</b> We experienced some set-backs during our initial restoration |
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| 47 | attempts. This was not that unexpected since the machines have been sitting |
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| 48 | idle for several decades. We have at least two different problems in the |
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| 49 | machine. Without diagnostic programs, any repair attempt would be in vain. Just |
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| 50 | the keyboard/printer test shows an error:<br> |
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| 51 | |
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| 52 | "E0001 INVLD" denoting an erroneous |
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| 53 | address in the switch register for that particular test. Unfortunately the |
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| 54 | address set on the switches is correct so another problem is still lurking in |
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| 55 | the machine.<br><br> |
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| 56 | |
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[669] | 57 | <b>13.09.2014:</b> The next step involved testing the card punch 1442 by means of |
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| 58 | the diagnostic tests. The test program punches cards with certain patterns in |
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| 59 | a first step. These cards are then read back in a second step and compared |
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| 60 | with the expected patterns to reveal any differences. Our punch only punches |
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| 61 | the first 40 columns of a card which is obviously an error. Fortunately, the |
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| 62 | console printer works fine despite the error message generated by the |
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| 63 | console-test program (07.09.2014).<br><br> |
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[667] | 64 | |
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[672] | 65 | <div class="desc-left"> |
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| 66 | <a href="/shared/photos/rechnertechnik/ibm1130/SLT-layout+schematic.pdf"> |
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| 67 | <img src="/shared/photos/rechnertechnik/slt.jpg" width="233" height="234" /></a> |
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| 68 | <p class="small"><a href="/shared/photos/rechnertechnik/ibm1130/SLT-layout+schematic.pdf">Opened SLT-block</a><br> |
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| 69 | Enlarge: click on picture!</p></div> |
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| 70 | |
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[669] | 71 | <b>20.09.2014:</b> We are currently creating a list of known problems regarding the |
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| 72 | 1132 printer. Its restoration is especially challenging. After being unused |
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| 73 | for more than 30 years, the oil has become gummy, so just powering the |
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| 74 | printer is not an option, too many things could and would be damaged. Thus, |
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| 75 | all moving parts have to be inspected manually. It turned out that the |
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| 76 | central driveshaft is stuck. Therefore, the motor was removed and restored |
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| 77 | indecently. In addition to this, the remaining printer parts have been heated |
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| 78 | with a heater blower and sprayed with W40 lubricating oil. After these steps, |
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| 79 | the driveshaft could be rotated manually, so the motor was installed again. |
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| 80 | Now the mechanics of the printer runs smoothly without any signs of trouble.<br><br> |
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| 81 | |
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[672] | 82 | <b>30.09.2014:</b> The printer test finally works but there were still problems in the printout: |
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| 83 | Characters were overprinted every 16th column. This could be traced back to |
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| 84 | the buffer memory of the printer. Bit 6 of the buffer, an SLT-flip-flop, was |
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| 85 | stuck. How an SLT circuit can be repaired is described in more detail here: |
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| 86 | <a href="/shared/photos/rechnertechnik/ibm1130/SLT-layout+schematic.pdf">Deeper insights.</a> |
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| 87 | |
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| 88 | |
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| 89 | |
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[667] | 90 | <p><b><em>This section will be gradually continued.</em></b></p> |
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| 91 | |
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