CBM II Parts Low Profile B128(610)/B256(620) High Profile CBM128(710)/CBM256(720) B(6x0) CBM(7x0) Location Location Part Number Description U26, U58 U9, U29 2016 (2) 1K x 8 static RAM U64-U79 U37..U90 4864-2 (16) 64K x 1 dynamic RAM U29-U36 U39..U91 4864-2 (8) 64K x 1 dynamic RAM (256K) U45-U52 U40..U92 4864-2 (8) 64K x 1 dynamic RAM (256K) U9 U26 6509A CPU U2, U28 U8, U84 6525A (2) TPI U1 U11 6526A CIA U15 U7 6551A ACIA U10 U6 6581 SID U7 U10 68B45 CRTC U18 U75 906114-04 82S100 PLA U18 U75 906114-05 82S100 PLA U41 901232-01 2332A ROM character U25 901237-01 2332A ROM character U59 U12 901241-03 2364A ROM Basic 256 4.0 8000-9FFF U59 U12 901243-02 2364A ROM Basic 128 4.0 8000-9FFF U60 U13 901240-03 2364A ROM Basic 256 4.0 A000-BFFF U60 U13 901242-02 2364A ROM Basic 128 4.0 A000-BFFF U61 U17 901244-03 2364A ROM Basic 256/128 4.0 E000-FFFF U59 U59 901241-04 2764 EPROM Basic 256 4.0r 8000-9FFF U59 U12 901243-04 2764 EPROM Basic 128 4.0r 8000-9FFF U60 U60 901240-04 2764 EPROM Basic 256 4.0r A000-BFFF U60 U13 901242-04 2764 EPROM Basic 128 4.0r A000-BFFF U61 U17 901244-04 2764 EPROM Basic 256/128 4.0r E000-FFFF NOTE: -04 ROMs were not officially released. NOTE: 906114-05 PLA is necessary for proper operation of a coprocessor.