Reply To: Sega Master System on NTSC Model 1 MD/Gen — Intermittent Black Screen

[d020]

Congratulations on your v1.1 firmware @megari! With a recently-arrived “USBasp clone”-type programmer I was able to update the Koryuu with it and made a new video using a MiniDV camera on a tripod. Two CRT on the left, one (de-)tuned to show the vertical blanking area. Two HDTV on the right, top with Koryuu, bottom with RetroTINK-2X by Mike Chi. I will include a schematic at the end of the post.

The intermittent black screen symptom does not seem to significantly differ with the v1.1 firmware. On a more positive note I believe Koryuu remains preferable overall to the RetroTINK-2X, which with SMS games on my NTSC Genesis can produce a signal that lacks color (in the linked video it does this for the first one or two frames of some scene transitions but it can be for much longer). I would be happy to make further testing or video if it would be useful!

 ===========
 = Genesis =                 
 ===========
  | (stock A/V
  v   cable)
 ==========================================
 = Component Video Distribution Amplifier =
 =          (CVBS leads on Y)             =
 ==========================================
  | CVBS        | CVBS         | CVBS
  v             v              v
 =========     ==========     ============
 = CRT A =     = Koryuu =     = Retro    =
 =========     ==========     =  TINK-2X =
  | CVBS        | YPbPr       ============
  v  loop       v              | HDMI
 =========     ==========      V
 = CRT B =     = HDTV A =     ============
 =========     ==========     =  HDTV B  =
                              ============
 
 Genesis      : VA6 w/Sony CXA1145 video encoder chip
 Koryuu       : v1.1 firmware
 RetroTINK-2X : stock firmware 
 HDTV A       : Samsung LN32D430G3D
 HDTV B       : AOC L22W861