VT02 / VT03 pinout

                             _______
                            /    91 \ -- GND
                   /CS0 <- / 1    90 \ -> CPU A5
                  /CS1 <- / 2      89 \ <> CPU D6
               CPU D5 <> / 3        88 \ -> CPU A6
             CPU A14 <- / 4          87 \ <> CPU D7
             CPU D3 <> / 7            86 \ -> CPU A7
            CPU A2 <- / 8              85 \ -> CPU A14
           CPU D2 <> / 9                84 \ -> CPU A8
          CPU A1 <- / 10                 83 \ -> CPU A13
            GND -- / 11                   82 \ -> CPU A9
        CPU D1 <> / 12                     81 \ -> CPU A12
       CPU A0 <- / 13                       80 \ -> CPU A10
      CPU D0 <> / 14                         79 \ <- CPU CLK (1.8MHz)
        R/W <- / 15                           78 \ -- VCC
   /ROMSEL <- / 16                             77 \ -> CPU A11
     /IRQ -> / 17                               76 \ <- $4016.0
 PPU R/W <- / 18                                 75 \ <> IOCLK1
    VDE <- / 19                                   74 \ <> IO2
    VCC -- \ 20                                    73 \ -> IO1
     ERS <- \ 21                                    72 \ <- $4017.4
CIRAM A10 -> \ 22                                    71 \ -> IO0
    PPU A6 <- \ 23                                    70 \ <- $4017.3
     PPU A7 <- \ 24                                    69 \ <- $4016.1
      PPU A5 <- \ 25                                    68 \ <- $4017.2
       PPU A8 <- \ 26                                    67 \ <> IOCLK0
        PPU A4 <- \ 27                                    66 \ <- $4017.1
         PPU A9 <- \ 28                                    65 \ <- /FH
          PPU A3 <- \ 29                                   64 / -- VCC
          PPU A10 <- \ 30                                 63 / <- /BTS
            PPU A2 <- \ 31                               62 / <- $4017.0
            PPU A11 <- \ 32                             61 / -> Crystal Out
                 VCC -- \ 33                           60 / <- Crystal In
               PPU A1 <- \ 34                         59 / <- /IJSE
               PPU A12 <- \ 35                       58 / <- /16B
                 PPU A0 <- \ 36                     57 / <- OBS
                    /ERS -- \ 37                   56 / -- GND
                   /SFCCS -- \ 38                 55 / -> Audio Out 1
                    PPU D0 <> \ 39               54 / -> Audio Out 0
                     PPU D7 <> \ 40             53 / <- /RST
                      PPU D1 <> \ 41           52 / <- Test Pin
                       PPU D6 <> \ 42         51 / -> VOUT
                        PPU D2 <> \ 43       50 / <- REG0
                         PPU D5 <> \ 44     49 / <- REG1
                          PPU D3 <> \ 45   48 / <- /LCDEN
                           PPU D4 <> \ 46 47 / -- GND
                                      \_____/

• /CS0: /CS for $6000 - $7FFF
• /CS1: /CS for $8000 - $FFFF
• VDE: Video Data Output Enable; I/O in OneBus Mode
• ERS: External ROM chip selector / Power on Indicator / I/O in OneBus Mode
• /SFCCS: Swap the function of /CS0 and /CS1 when low
• /LCDEN: Enable LCD Output for Testing
• REGx: Region Selector. All 0 = NTSC, All 1 = PAL
• OBS: OneBus Mode Enable
• /16B: 16 bits data bus selector in OneBus Mode. A0 will decide the low byte or high byte of data on CPU D0-7
• /IJSE: Internal Joystick Enable when XJOYSEL = 0
• /BTS: Bus tristate enable
• /FH: Force /CS0 and /CS1 High
• IOCLKx: Clock of I/O or XCUP47, can be video extention address
• IOx: I/O interface Output pins or Video extention address

Sources

• VT02 Datasheet: http://www.vrt.com.tw/old_site/admin/upload/datasheet/VT02%20Data%20Sheet%20RevisionA5_ENG__1.pdf
• VT03 Datasheet: http://www.vrt.com.tw/old_site/admin/upload/datasheet/VT03%20Data%20Sheet%20RevisionA6_ENG.pdf