CDP18S030: A Microcomputer in a Briefcase

Description

Once upon time I chanced to an abandoned brief case with letters RCA on it. Reminded me of the COSMAC kits and tools of late 70's early 80's. The briefcase did not look very interesting, except that it seemed to have a calculator in it. Later I found the documentation in the net and discovered the nature of the case. Unfortunately the device did not have the CDP1802 chip when I got it, but fortunately I had bought some of those from a second hand and recycled electronics dealer (Bebek). Until now it has been sitting in the pile of projects to be done later. Now has the time come to check it out: how much restoration, verification, and repair it needs.

Project Logs

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Restoration of the power supply
Lauri Pirttiaho • an hour ago • 0 comments

The restoration of a computer often begins with the power supply. It is critical not to turn on the potentially degraded and fragile device until the safety of the power supply and the other circuitry has been verified to not contain shorted components, especially the electrolytic and other capacitors. There is also a chance there are degraded solderings which may trigger a major destruction rare or unobtainable components.
The first step in this project was to take out the power supply and verify that it is wired for the correct voltage (220V for Europe).
Though a bit unorthodox, also the PH-163 power cord receptacle was changed to a modern IEC C8 one for which cables are available.
The original socket will be saved for a chance that the fitting plug becomes available.
The next step is to get familiar with the power supply. Though the CDP18S030 manual has the schematics and component layout of the logic board, the only thing about the power supply is the instructions for the voltage selector wiring.

Therefore the next step is to draw the circuit diagram of the power supply.