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Showing the Signals

A project log for Recreating the Jupiter Ace

Recreation of the 'Fastest computer in the Universe' that runs FORTH.

Cees MeijerCees Meijer 04/18/2021 at 20:020 Comments

My system works fine, but it appears that others are building my design too. And to assist in fault finding it is probably a good idea to document some signals  so other builders can compare their results with mine.

Oscillator

Oscillator output:
U23-8 Oscillator output 6.5Mhz
U9-6 (CNT3)
U10-6 (CNT6)

Z80 - Pin 6 - Clock input
U21-12 (FIELD) U19-11 (INT)

Video Section

Basis of the video signal is the 50Hz signal on U11-10. In the pictures below this is shown in the top, and used to sync the oscilloscope. Video signals were recorded with a LCD monitor connected.

U11-10 (50Hz) - U25-11 (Sync)
Base of Transistor Q5. Note the scale is 50mV/Div
Base of Transistor Q4 - ( VIDEO )
Cathode of D14, video output with a line of characters on the screen
Close up of video signal

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