
Zenith Z-150 keyboard conversion project: direct connection of Black Pill to the matrix.
Earlier 100-1886 version with black logo has different PCB.
Make example for this keyboard (after setting up your build environment):
make handwired/z150:default
See the build environment setup and the make instructions for more information. Brand new to QMK? Start with our Complete Newbs Guide.
Z-150 has 11x8 matrix. It's ghost-free thanks to the diodes.
Columns are located under NEC D8049HC MCU IC:

Rows are connected to unmarked 24-pin MUX IC:

LEDs (from left to right): NumLock, CapsLock, ScrollLock:

Their anodes are connected to VCC through 220Ω resistors.

You can keep the original resistors, but with Black Pill or any other 3.3V controller the LEDs may seem a little dim. Try 150Ω or close value if you want to fix that.
Suggested mount position for the Black Pill (view from the bottom side of the PCB):
      R0  R1  R2  R3  R4  R6          R9  LC  LN  LS
,--------------------------------------------------------------------,
|B12 B13 B14 B15  A8  A9 A10 A11 A12 A15  B3  B4  B5  B6  B7 3V3 GND |---,
|                                                                    |USB|
|B11 B10  B1  B0  A7  A6  A5  A4  A3  A2  A1  A0 RST C13  B9  B8 GND |---'
'--------------------------------------------------------------------'
  C0  C1  C2  C3  C4  C5  C6  C7  R5  R8  R7  RA    
make handwired/z150:default:flash