int e l 21 VOLTS 21 VOLTS 7407 (PIN 5) P1.5 OF 8052AH 10K Ω 7407 74LS32 10K Ω 4.7K Ω 2N4403 P1.5 P1.4 4.7K Ω 2N4403 +5 1N270 (PIN 6) P1.4 OF 8052AH 1K (PIN 1) Vpp +5 VOLTS 7407 PGM (PIN 27) 10K TO ADDRESS DECODE (ACTIVE LOW) CE OE +5 4.7K ANY NON-INVERTER TTL GATE MAY BE USED 2 7 6 4 2 7 1 2 8 2 7 3 2 A ~ TO ADDRESS DECODE (ACTIVE LOW) CE OE PSEN 74LS08 PSEN 74LS08 7407 RD Figure 4A. Programming 2764‘s/27128‘s Figure 4B. Programming 2732A‘s RD +25 VOLTS P1.5 OF 8052AH 10K Ω 7407 74LS32 2N4403 P1.4 OF 8052AH 74LS04 4.7K Ω TO ADDRESS DECODE (ACTIVE LOW) 74LS32 CE/ PGM 1N270 +5V 74LS08 Vpp 10K 2 7 1 6 OE 74LS32 74LS08 PSEN RD Figure 4C. Programming 2716‘s - 143 -