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    Software Development, Vintage Computing

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  1. Yes, the B version is indeed much cleaner! The map image looks great while the downloaded jpg shows a long horizontal stripe of black pixels. Looks like something went wrong during stitching...
  2. I rotated the die image 90° clockwise and opened it in Inkscape. Pin 1 could be easily found because it's marked with "1" I then annotated all pads with the corresponding pin numbers and type. The power rails ("VSS" and "VDD") could be easily spotted. All other pins except three ones could be classified to be either input (red "I") or I/O pins (blue). I believe that pads 2-4 are there for testing purposes as described in chapter 7 "Testability". It looks like they were never connected to anything. The overall chip structure seems to match the description in the alrea
  3. Thank you! Is there any way to download the die shot from the map viewer? I'm eager to run degate on it.
  4. Yes. Next step would be to set up degate to locate all internal cells as well as find all power connections... There are unused pins that appear as blank pads.
  5. It looks like our BBU is a standard VTI gate array of type VGC1900 as indicated by the markings on the silicon die. VTI Gate Array databook (can be downloaded here) specifies its properties as follows: number of internal cells: 1288 number of input-only cells: 35 number of I/O cells: 58 number of power pins: 8 number of testability pins: 3 Pins total: 104 The above databook explains the exact topology of this gate array. Figure 2-3 on page 17 shows the anatomy of an internal cell of this chip as it was implemented in silicon. Have fun
  6. What's about giving degate (https://degate.org) a try? I personally didn't play with it yet so I can't say how well it performs for real-world use cases. By the look of things it was designed to semi-automatically identify common building blocks of ICs in die images. Considering the amount of gates in the said BBU reversing it manually may take a lifetime. Any tool that aids in speeding up such a task is highly appreciated IMHO...
  7. Thank you a lot, @MrFahrenheit It indeed works as you described. It looks like my restoration job was a success. I'm really happy now.
  8. Okay, let's get back on track. I would like to know if someone owning a PowerMac 6100 can play back audio CDs using the internal speaker. I'm going to check next if I can record CD audio with an audio recording software. The Sound control panel allows to select "Audio CD" as sound input device.
  9. Yes, I have the audio wire installed. Can it be a driver related issue?
  10. Yes, I did. I attached headphones to it. I hear alert sounds but no CD sound.
  11. I haven't tried it yet. The drive doesn't have any audio jack. It only has a connector marked "Audio out". It's rather difficult to attach a regular speaker to it without a special cable.
  12. Fellow Macintosh enthusiasts, I recently recapped an old CD-ROM drive in my Macintosh 6100/60 AV. It seems to work fine reading all CDs/CD-Rs I put in. When I insert an audio CD, the drive seems to play it back but I hear no sound. All controls in the Apple CD player including starting/stopping of playback, jumping between tracks as well as ejecting work flawlessly. The audio cable between the CD-ROM drive and the motherboard is attached. The internal speaker is confirmed to work either - I hear the startup bong as well as alert sounds. Volume control also w
  13. @LaPorta I always do an incremental recap replacing caps one by one while double-checking every change and ensuring that everything is installed and soldered properly. I also thoroughly clean the board along the way. I've also learned it the hard way by sacrificing one power supply and one PowerMacintosh board.
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