retrobits | Is this SWP CoPower 88 working or not? Diagnosing a new fault @retrobitstv | Uploaded November 2022 | Updated October 2024, 2 hours ago.
Maybe MS DOS *does* work on the Kaypro 4 Plus 88… How did I not notice this before?!

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Hantek 2D72 Handheld Oscilloscope - amzn.to/3fZ52xF

Previous Episode:
Kaypro 4 Plus 88 - Testing MS DOS - youtu.be/nroIdwecx2k

Jim Leonard’s Channel - youtube.com/TheOldskoolPC

SWP CoPower88 Schematics - hardwarecomputerist.atariverse.com/pages/peripheral/peripheral.interface.htm#ATR8000
(Thanks to MrFish on AtariAge!)

Don Maslin ROM Archive - retroarchive.org/maslin/roms/index.html

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00:00 Introduction
00:21 The problem, revisited
02:20 Removing the SWP CoPower 88 board
03:55 Testing with only half of the RAM
06:24 Diagnosing with a new Hantek scope
09:07 Diving into the schematics
11:29 Is it the 8088?
14:08 Some new LS logic
15:24 Grasping at straws
16:19 Swapping RAM and…
17:30 … the conclusion?

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