C900 - workstation - motherboard Position # Pins Markings -------- -------- -------- U1 48 Z8001APS (Seg CPU) U2 48 Z8010APS (Z-MMU) U3-U4 20 SN74LS245 U5 40 Z8036APS (Z-C10) U5 20 SN74LS244N U6 20 SN74LS244N U7 20 SN74LS244N U8 20 SN74LS373N U9 14 SN74LS04N U11 14 SN74LS08N U12 14 DM7407 U13 14 SN74S04N U14 14 SN74LS93N U16 16 M58321 "OKI" Japan 4456 U17 28 "C900 Boot-H V1.0" (on a N82S100N K8433) U18 28 "C900 Boot-L V1.0" (on a N82S100N K8433) U19-U20 16 SN74LS257BN U21-U52 16 41256c U53 14 SN74S74N U54 28 "NEW" (on a N82S100N K8433) U55 14 DM74LS05N U56 20 SN74LS373N U57 16 SN74S138N U58 24 DM74LS154N U59 14 TI428B, NESS6N U60 14 DM74LS05N U61 14 SN74LS27N U62 14 SN74LS74AN U63 14 SN74LS00N U64 13 SN74LS74AN U66 40 Z8036APS U67 20 SN75160AN U68 20 SN75161AN U69 14 DM7407 U72-U73 14 DM7407N U74 40 Z8030APS (Z-SCC) U75 14 MC1488 U76 14 MC1489P U77 14 MC1488 U78 14 MC1489P U79 48 MOS 8716R1, 1501-19A U80 20 SN74LS374N U81 20 SN74LS274N U82 16 SN74LS193N U83 16 SN74LS193N U84 20 SN74LS244N U85 20 SN74LS244N U201 40 MOS 6508R2S U202 20 SN74LS245N U203 16 SN7445N U204 48 8723R1 U206 14 SN7406N U207-U210 8 SN7477P U211 14 SN7406N U212 18 HA16631P U213 14 SN74LS32N ----------------------------------------------- C900 - workstation - lr video board Position # Pins Markings -------- -------- -------- U1 16 SN74LS166AN U2 24 280217-01 R.B. "PC Char" U3 20 SN74LS374N U4 20 SN74LS273N U5 24 AM9128 20PC U6 24 AM9128 20PC U7 24 SN74LS646NT U8 24 SN74LS646NT U9 40 HD46505SP-2 HD68B45SP U10 16 SN74LS138N U11 16 SN74LS139AN U12 16 SN74LS175N U13 20 SN74PAL16 R6ACN U14 14 SN74S04N U15 14 SN74S74N U16 16 74LS257APC U17 16 74LS257APC U18 28 "ZRSEL" 02 "1A93" U20 14 SN74LS393N U21 20 SN74S374N U22 28 380212-02 "4A75" U23 14 SN74LS74AN U24 16 SN74LS162AN U25 16 SN74S174N U26 16 74LS257APC U27 14 SN74LS11N U28 14 SN74LS00N U29 20 SN74LS245N U31 40 Z8030APS "Z-SCC" U32 14 MC1488 U33 14 MC1488 U34 14 1488N U35 14 1489P U36 40 (open) U37 14 1488 U38 14 MC1488 U39 14 1488 U40 14 1489P (crystal found marked at 16.257 mhz)