Schematic
Toshiba BC-0802 Calculator: Reverse-Engineered Schematic
Schematic of the Toshiba BC-0802 desk calculator of 1972 with NEC LD8035 or Toshiba fluorescent tubes.
Schematic
Schematic of the Toshiba BC-0802 desk calculator of 1972 with NEC LD8035 or Toshiba fluorescent tubes.
1• 8• 2 TOSHIBA E6505 TOSHIBA E6504 U4 12 Vacuum Vacuum V–7.5 3 Fluorescent Fluorescent 28 220K 150K 220K Display Displays 1K 1K 1.5K 1 A495 A495 200p Ø Sa V–15 V–27 V–37 16 75p 75p Sb U4.1.14.13 17 C372 10K Sc U1.6.7.10 1K 2K 47K 47K 2K 1K 18 100K Sd U1.1.14.13 19 Se U1.2.3.12 20 V–15 Sf U1.5.4.11 21 Sg U4.6.7.10 10 22 16V Sp U4.5.4.11 24 220K o m a f b V–15 m g o ØD1 ØD2 ØD3 ØD4 ØD5 ØD6 ØD7 ØD8 ØD9 ØD10 Toshiba e c TMS0105 d p n.c.: 23 NK5 NK15 NK14 NK13 NK12 NK11 NK10 NK9 NK8 NK7 NK6 47K A502 1 2 3 4 5 6 7 8 9 0 100K 100K V–37 V–37 26 ØD11 C372 NML 13 NK17 24K 220K ØD10 2• 12 ØD10 ØD9 220K C ÷ += –= DP CI 11 V–15 V–15 V–37 ØD9 25 V–15 NK1 FCT ØD8 U2.1.14.13 10 ØD8 NK16 NK2 ØD7 U2.2.3.12 9 ØD7 NK3 ØD6 U2.5.4.11 8 ØD6 K NK4 27 ØD5 U2.6.7.10 K 7 ØD5 NK20 NK18 ØD4 U3.1.14.13 F 6 ØD4 NK21 ØD3 U3.2.3.12 0 2 5 ØD3 U4.7 DPPOS NK22 2 NK19 ØD2 U3.5.4.11 4 ØD2 U1.3 ØD1 U3.6.7.10 3 ØD1 14 15 V–7.5 V–15 C509 8 270 pk 220 220 U1::4 NP3 25V 25V RD9A bk Toshiba NP4 T3084 RD9A V–7.5 pk 220 220 Notes NP5 25V 25V 270 • Digit scanning is MSD first (ØD2 occurs before ØD1). • Clock rate is 222 KHz, number cycle is 517 Hz. POWER A495 0.1A V–15 • Capacitance in microfarads unless otherwise specified. bu NP1 • This drawing based on unit with Serial No. C56128. display filaments 120VAC 82 10 0.04A bu 1.5K • 2001 Mar 14: Initial drawing / bhilpert. 16V 2020 Feb: Format updates / bh. NP2 220K Toshiba BC-0802 47 50V Calculator RD11A V–27 gn NP6 Page: 1 of 1 Printed: 2020 Feb 4 V–37