Sunday, 26 April 2015

First test of Yamaha V9938

Yesterday the "hard to find" 21.477 MHz crystals arrived from Aliexpress :-)
Today I soldered the SDIP64 adapter PCB and tested the V9938 with the R65C02 @ 3.58 MHz (Yamaha cpuclock =1/6).
I connected the 32k SRAM with the latch - like at the 9129 - and it works!

I connected the composite out with an simple emitter follower to my Commodore 1084S.
You see - there's something wrong - it looks a little bit shaked ;-) - but I have a picture!
Tomorrow I will check the SRAM connections and test the circuit with a 16-bit DRAM.


  1. Are there any YOUTUBE videos of this Amazing project ??

  2. I have only some old Videos with games on my lc64 (without sprites):
    Now the LC64 design is finished and fully working - I only have to build it on PCB.

    After finishing the LC64 I will build my own homebrew 65c02 with the v9938 or v9958. I will write an own OS for that machine...

    1. Cool..can't wait to see it !

    2. Did you ever make a PCB for this project.. >? As I'm sure plenty of people would like to build their won.

  3. Hi, thanks for your interest.
    Currently I draw the schematics in eagle and after that I desgin a layout.
    You will find it here ;)
    I just got the 74LCX245 3,3/5V databusdriver and wait for the 74ABT245 addressbusdriver.