In this video I repair a Mac 512k motherboard with an unknown RAM expansion card on it. In part 1, we looked at two Mac motherboards with unusual RAM expansion cards. The Mac 128k motherboard worked, but I left the Mac 512k motherboard for another video. This is that video! Figuring out what was causing this motherboard to not boot and display video issues required me to study schematics and try to understand the architecture of these early Mac machines, and it paid off!
Part 1: https://youtu.be/XLn_3KI_CbM
Part 2: This part!
-- Video Links
ROM Matrix:
https://docs.google.com/spreadsheets/d/1wB2HnysPp63fezUzfgpk0JX_b7bXvmAg6-Dk7QDyKPY/edit#gid=840977089
Sad Mac Error codes:
https://tinkerdifferent.com/resources/sad-mac-error-codes.82/
Macintosh 128k technical documentation:
http://bitsavers.informatik.uni-stuttgart.de/pdf/apple/mac/prototypes/1983_Twiggy/Macintosh_Hardware_Memory_Map_19830413.pdf
ROM Disassembly:
https://www.bigmessowires.com/rom-adapter/plus-rom-listing.asm
PicoRC:
https://github.com/dekuNukem/PicoRC/blob/master/README.md
https://www.tindie.com/products/dekunukem/picopsu-adaptor-for-ibm-5155-ibm-pc-compatibles/
Adrian's Digital Basement Merch store:
https://my-store-c82bd2-2.creator-spring.com/
Support the channel on Patreon:
https://www.patreon.com/adriansdigitalbasement
Adrian's Digital Basement (Main Channel)
https://www.youtube.com/channel/UCE5dIscvDxrb7CD5uiJJOiw
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