Main channel: We made some unbelievable discoveries about this Plexus P/20! (Patreon)

Published:

2024-06-08 18:15:53

Imported:

2024-06

Content

Hello my patrons! In this episode of jUNIX (June UNIX), I'm working on the Plexus P/20 again. In the last episode, we left off with this machine having a critical failure that prevented it from working. The diagnostic error was somewhat non-descriptive, so I wasn't sure where to start in diagnosing the failure.

In this video, with the help of the fine folks on the Usagi Electric discord server, we uncover the mystery of the error with gave me the critical pointers I needed. This allows me to start the process of repairing the machine, where I am also helped by some unbelievable data we discovered on the hard drive image I made of this machine.

The whole story is quite amazing, I hope you enjoy it.

Thanks for your support!

Direct link: https://youtu.be/Ve1SuuRkx_o

Files

We made some unbelievable discoveries about this Plexus P/20!

Part 1: https://youtu.be/iltZYXg5hZw Part 2: https://youtu.be/BPOHWBuYMGg Part 3: https://youtu.be/_IrxvDE6Fyo Part 4: This part -- Links Discord channel at Usagi Electric: https://discord.gg/qYCvAJQk My Github Repo (with ROM dumps and images) https://github.com/misterblack1/plexus-p20 Plexus P/20 Brochure: http://www.bitsavers.org/pdf/plexus/brochures/Plexus_P15_P20_Brochure_1985.pdf Plexus Unix: http://www.bitsavers.org/pdf/plexus/brochures/Plexus_SYS_5.2_Brochure_1985.pdf MFM emulator: https://www.pdp8online.com/mfm/mfm_old.shtml Fujitsu Hard Drive Brochure: https://archive.org/details/bitsavers_fujitsubro1984_2565589 Omti 5200 Manual: https://oldcomputers.dyndns.org/public/pub/roms/omti-5400/omti_5000_series_reference_aug85.pdf Adrian's Digital Basement Merch store: https://my-store-c82bd2-2.creator-spring.com/ Adrian's Digital Basement ][ (Second Channel) https://www.youtube.com/channel/UCbtwi4wK1YXd9AyV_4UcE6g Support the channel on Patreon: https://www.patreon.com/adriansdigitalbasement My GitHub repository: https://github.com/misterblack1?tab=repositories -- Tools Deoxit D5: https://amzn.to/2VvOKy1 http://store.caig.com/s.nl/it.A/id.1602/.f O-Ring Pick Set: (I use these to lift chips off boards) https://amzn.to/3a9x54J Elenco Electronics LP-560 Logic Probe: https://amzn.to/2VrT5lW Hakko FR301 Desoldering Iron: https://amzn.to/2ye6xC0 Rigol DS1054Z Four Channel Oscilloscope: https://www.rigolna.com/products/digital-oscilloscopes/1000z/ Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier: https://amzn.to/3adRbuy TL866II Plus Chip Tester and EPROM programmer: (The MiniPro) https://amzn.to/2wG4tlP https://www.aliexpress.com/item/33000308958.html TS100 Soldering Iron: https://amzn.to/2K36dJ5 https://www.ebay.com/itm/TS100-65W-MINI-Digital-OLED-Programmable-Soldering-Iron-Anti-static-Structure/113382669853 EEVBlog 121GW Multimeter: https://www.eevblog.com/product/121gw/ DSLogic Basic Logic Analyzer: https://amzn.to/2RDSDQw https://www.ebay.com/itm/USB-Logic-DSLogic-Basic-Analyzer-16Ch-100MHz-4Ch-400MHz-Xilinx-Spartan-6-FPGA/202543965672 Magnetic Screw Holder: https://amzn.to/3b8LOhG https://www.harborfreight.com/4-inch-magnetic-parts-tray-90566.html Universal ZIP sockets: (clones, used on my ZIF-64 test machine) https://www.ebay.com/itm/14-16-18-20-24-28-32-40-pin-IC-Test-Universal-ZIF-Socket-Fs/303206721971 RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI) http://www.retrotink.com/ Plato (Clone) Side Cutters: (order five) https://www.ebay.com/itm/1-2-5-10PCS-Micro-Scissor-125mm-PLATO-170-Electronics-Cutter-Side-Cutting-Pliers/163458746184 Heat Sinks: https://www.aliexpress.com/item/32537183709.html Little squeezy bottles: (available elsewhere too) https://amzn.to/3b8LOOI --- Instructional videos My video on damage-free chip removal: https://www.youtube.com/watch?v=XQVjwPsVFd8 --- Music Intro music and other tracks by: Nathan Divino @itsnathandivino