Digital Oscilloscope

Digital oscilloscope project created with wirewrapped microprocessor and hand built LED array.

This is a digital oscilloscope that I built in 1987 in college.  It is based on the early generation 8088 CPU.

This is an excerpt from my project log book.  My professor made us keep a log book of project design, circuit diagrams, and source code.

Download project log book (pdf file)

Partial circuit diagram from log book.

I tediously built the 28×16 digital led display.

I had to melt each side of every LED so that the would fit close together.

448 LEDs soldered into a XY grid.

It takes a lot of wirewrapping to connect all of the circuitry.  This was the industry technique for prototyping electronic circuits in the 80′s.

This is an early test program (assembly source code), which was stored on the erasable programmable memory chip (EEPROM).  Assembler programming is just 1 step above programming at the binary level.

Comments

  1. Dooda
    October 23rd, 2010 at 09:30 | #1

    Should have invested in pro PCB manufacture. Your design on proto-board looks like poo. This would NEVER happen in Thailand !

  2. November 21st, 2010 at 13:32 | #2

    @Dooda
    This was a college project back in the 80′s. PCB solutions were out of my budget at that time, plus my college professor instructed us to use the wirewrap tool.

  3. March 1st, 2012 at 11:34 | #3

    I second what Alan said. Perhaps today, with decent autorouting PCB design software and and CNC controlled tools that can cut the PCB instead of etching it, using a PCB would have been faster. Having been involved in a similar sized project in the 1980s, I can definitely say that wirewrap was the fastest way to a prototype at that time. And Alan has actually done a very neat wirewrap job here. This makes me want to put my project on-line too.

  4. Stevve
    March 16th, 2012 at 01:41 | #4

    Pretty neat! Do you use it for any actual waveform analysis?

  5. March 16th, 2012 at 09:18 | #5

    I haven’t used it for much real waveform analysis since college. My degree was a Bachelors in Electronics Engineering, but I’ve been doing computer programming since. Go figure.

  6. November 10th, 2013 at 14:25 | #6

    Alan,
    Ignore the idiot that has displayed total ignorance of art of breadboarding, or of much in electronics.
    based on a long history of breaboarding, lots of troubleshooting and design, your work is quite acceptable
    by the standards of those of us that have and are still designing new items to use and understand.

    cfh

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