Yoshizen's Blog

CYBER SPACE — (and Z80 mini-computer)

It is 25 years  since  Dot Com was first created,  and 20 years since  WWW  was invented.

One of my old colleague,  Camera Critics,  Kazuo Taira  was one of the pioneer of the PC networking, using

acoustic telephone modem and he organized the Photographer’s Computer Network in Japan.

It’s shame Mr.Taira  is no longer with us.  Unfortunately  we in the creative field tend to lose the friends who

tend to be a heavy drinker.  ( Do you know,  the average life-span of Rock musicians are 38 something,

of cause it may not caused by the alcohol alone )

And since then, our lives are more and more entwined with the Computer and the Internet.

Nearly 20 years ago,  I made a small computer using Z80 CPU,

designed from the scratch.  ( Left  Photo)

( I would say, it’s a half sculpture, half computer )

Its operates on only 10 MHz clock speed and having 512 Kb memory,

which needs to be programmed by Machine Code.

—– In electronics, to design and to build is one thing and

to make it works is the another.

Eliminate all the glitches and instability etc etc are the hard part.

—– As the definition,  computer operates on the data in the

memory,  once the memory was corrupted,  it needs to re-program from the start.

( It was the time of  UV erasable  memory,  before easy to re-program  Flash-memory )

After this experience,  I became a computer skeptic ” Computer can make mistakes ” hence, even now

I don’t use Credit Card and I rather like to use hard-wired design,  not soft control.

In this reason, I honestly admire the person who can design and manufacture a  10 GHz device which works

in any environment  reliably.


In another side of the revolution,  the Internet is becoming almost a monster, and the Necessary Evil.

Since  I  started to use Email,  I wrote very few letters  which  needed to be a signed evidence.

—– The trouble of Net is their intrusive activities.  As everybody knows,  Google / Gmail is

watching our use of web and the contents of communications word by word. ( Cookies, hidden files etc)

When I heard about  Facebook,  I instantly felt their dubious nature  ” Why do they need to have so much

detailed personal information ? “—– obviously they are  the salable commodities.

Without having such profitable return,  what is the point to provide free service.

Personal info’ used to be sold to the marketing / direct mail company before.  Now the Internet provider,

social networking site are the Marketing/ Advertising/ Direct-mailing/ Delivery Service  All-in-one.

(When  I got an Email from one of our Old-boy telling, he has reached to the grand age, the Ads on right hand

column are all cheap Funeral service and the international flower delivery — Great, thank you very much :-D)

So that from the beginnings I didn’t use my real name to open Email account, and never sign up the

Website which asks Date of Birth.  ( Still, now Yahoo knows my DOB, obviously from the content of

the mail between me and my friend. )

With full name and the DOB, the one can hack-in and get the information of National Health, and

together with the Address,  it is possible to access the Banking information.


To live in peace, we have to be aware ” We are in the battle field ” which the Buddhists call  Samsara.

With technology and the Internet,  we opened the Pandora’s Box.   It’s a funny situation, as in the Informations

we are becoming almost naked,  in the same time our contact itself becoming even more indirect.

Just by  the chain of characters on the screen, a 30 years guy pretending as a 15 years old boy,  chatting

with a 40 years woman who pretending 13 years old girl. —– Yuck,  how  beautiful,   😀


Zen  rely on the Direct Transmission,  still what I’ve been trying here, is the triple, quadruple indirect

communications.  In order to type, I converted my feeling to the lingual form, and express it in the

bloody English, which typed chain of ASCII code traveled through unknown node here and there and

end up —– how do I know where.

As I thought,  I never met Buddha himself,  or  I have any idea , how many times the Mantra was translated

or re-written,  and  2500 years apart, someone try to reach the same conclusion as Buddha,

( in the point of indirectness, this is the far-most remote situation )

still, if its works,  a talk to others through  Internet may works too.

Thats what I’m thinking.


5 Responses

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  1. simon said, on April 30, 2012 at 07:58

    Do you have any schematics for this z80 comp. ?

    • yoshizen said, on April 30, 2012 at 11:48

      Yes of cause, (in somewhere) though, as I’ve had even a time in homeless,
      my possession had been pucked up in the boxes and went to a storage,
      since then lots of them hadn’t been even opened. I need to have a big search.

      Another matter is your level of knowledge = if you are completely amateur,
      you may need even the pin-number of each IC. But if you are good enough,
      you may see the structure hence all the wiring between ICs, such as 8bit Latch,
      its function and how and where to connect is self evident. = in this case,
      I can put closeup photos of each board in which you can see the name of IC.

      Or I can send you block-diagram with the name of each IC = with the Info’ of
      each IC the wiring would be self evident.

      Another alternative is, in the 80th, 90th many Electronic Magazine had
      article of Z80 mini-computer —– many of them, you still able to see and
      download the schismatics.( such as http://www.elektor = Google please )
      Though, you may not able to find some ICs now.

      Even the time when I built my Z80 computer, Hex to 7 segment display
      conversion IC was obsolete = I needed to make it with Diode-matrix in
      negative-logic (to save the number of Diodes).

      I hope this Info’ would be adequate still, if you like,
      please comment here again.

  2. simon said, on August 28, 2012 at 19:19

    I am mostly interested about keyboard, beacuse i have already built small z80 comp.

    • yoshizen said, on August 28, 2012 at 20:10

      About the Keyboard, first question is, whether you want to build it using discrete switches or utilize common ready made keyboard.
      Most crucial point is, input to Z80 is not serial like all the common keyboard but parallel (or need to put
      Serial to parallel converter).
      My design was using 4067 IC to convert 16 Hex input to 8bit parallel output.
      On the photo, looks like 2 story ad-on is to out put 16bit as a stuck.
      —– Please specify your requirement.
      By the way, I’ve built another keyboard for musical input 🙂

  3. Analog — Digital | Yoshizen's Blog said, on December 18, 2018 at 03:04

    […] each time and compared to the output voltage and count up to 65535 which mean max 1 volt.  And to do this with “Clock friqency” is all about digitizing process.  (Counting this to each three BGR (but actuary BGGR four) x 47 Mp is all about the imaging […]

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