PT-20 system board

Here's an old PT-20 system board (uses the old TC tape) and it was made in 1992.



LCD controller Hitachi HD44780S


Sanyo LC3517BML-15 2048 WORDS x8 BITS CMOS STATIC RAM


Mitsubishi M38004M8 cpu

decoding this cpu part number: M3800 4 = 640 bytes ram, M = mask rom, 8 = 32768 bytes ROM

NEC UB2908-A chip which must be some kind of gate array.