Fotos de memórias EPROM

Retirei a tampa superior de algumas EPROMs para tirar foto e comparar o tamanho dos chips e verificar que a miniaturização evoluiu. Uma 27C512 tem 32 vezes mais capacidade do que uma 2716  mas a área do chip não segue a mesma proporção.

Calculadora Binária

Uma calculadora que realiza operações aritméticas e lógicas com dois operandos de 8 bits. A entrada de dados é por lógica RPN  como nas calculadoras HP: primeiro entramos um dado de oito bits e apertamos Enter. Em seguida entramos com o segundo dado e apertamos a tecla da operação desejada. 

O circuito usa um PIC 16F628 com clock interno. O código Hex a ser gravado segue abaixo:

:100000006028A301A200FF30A207031CA307031C62

:100010005B280330A100DF300F200328A101E83E58

:10002000A000A109FC30031C1828A00703181528FC

:10003000A0076400A10F152820181E28A01C222844

:100040000000222808000310A00DA10DFF3E031898

:10005000232820085B280310A10CA00CFF3E0318E6

:100060002B2820085B280038031DFF300405031DE2

:10007000FF305B280404031DFF305B280038031D9C

:10008000FF308408031DFF3A5B281030A800A1014F

:10009000A001A70CA60C031C53282208A0072308C4

:1000A0000318230FA107A10CA00CA50CA40CA80BEE

:1000B000492824085B288313031383126400080073

:1000C00007309F008316FF3085008601831285016B

:1000D0008601BE01BF01C001BD013C10BC103C1136

:1000E0003E0886006400051EAD28C830012064006B

:1000F0003C19A82803013C18FF30B8000301BC18C4

:10010000FF30BA00380884003A083320BA00BB0038

:1001100064003A083B04031996284008BD003F08D4

:10012000C0003E08BF00BE013C10BC1064003C1C77

:100130009B28BE013C103E08A600A7010230A20089

:10014000A3014520B8002508B900380ABE00AD2833

:100150000310BE0D3C103C11BC106400851DE4284A

:10016000C830012064003C19DF2803013C18FF302F

:10017000B8000301BC18FF30BA00380884003A0800

:100180003320BA00BB0064003A083B040319D128AD

:100190004008BD003F08C0003E08BF00BE013C1043

:1001A000BC1064003C1CD628BE013C103E08A600D2

:1001B000A7010230A200A3014520BE00E4280310DD

:1001C000BE0C3C11BC103C106400051D6429C830F5

:1001D000012064003C19F5283F08BE074008BF0015

:1001E0003D08C000BC143C14642900303E180130A6

:1001F000840000303F1801303A20013903193E10C5

:10020000031D3E140030BE18013084000030BF18BA

:1002100001303A2001390319BE10031DBE1400300D

:100220003E190130840000303F1901303A20013975

:1002300003193E11031D3E150030BE190130840024

:100240000030BF1901303A2001390319BE11031DD6

:10025000BE1500303E1A0130840000303F1A0130D4

:100260003A20013903193E12031D3E160030BE1A12

:10027000013084000030BF1A01303A2001390319DF

:10028000BE12031DBE1600303E1B0130840000303C

:100290003F1B01303A20013903193E13031D3E175D

:1002A0000030BE1B013084000030BF1B01303A20FB

:1002B00001390319BE13031DBE174008BF003D08D6

:1002C000C000BC143C143C116400851CE529C830F6

:1002D000012064003C1976293E083F02BE00400818

:1002E000BF003D08C000BC143C14E52900303E1896

:1002F0000130840000303F180130332001390319E8

:100300003E10031D3E140030BE1801308400003042

:10031000BF180130332001390319BE10031DBE146C

:1003200000303E190130840000303F190130332085

:10033000013903193E11031D3E150030BE1901306D

:1003400084000030BF190130332001390319BE1178

:10035000031DBE1500303E1A0130840000303F1AE4

:1003600001303320013903193E12031D3E160030BF

:10037000BE1A013084000030BF1A01303320013929

:100380000319BE12031DBE1600303E1B013084004F

:1003900000303F1B01303320013903193E13031D88

:1003A0003E170030BE1B013084000030BF1B0130FF

:1003B000332001390319BE13031DBE174008BF00C7

:1003C0003D08C000BC143C143C116400051C652AA7

:1003D000C830012064003C19F6294008BD003F08E0

:1003E000C0003E08BF003C14BC10652A00303E1817

:1003F0000130840000303F1801303E2001390319DC

:100400003E10031D3E140030BE1801308400003041

:10041000BF1801303E2001390319BE10031DBE1460

:1004200000303E190130840000303F1901303E2079

:10043000013903193E11031D3E150030BE1901306C

:1004400084000030BF1901303E2001390319BE116C

:10045000031DBE1500303E1A0130840000303F1AE3

:1004600001303E20013903193E12031D3E160030B3

:10047000BE1A013084000030BF1A01303E2001391D

:100480000319BE12031DBE1600303E1B013084004E

:1004900000303F1B01303E20013903193E13031D7C

:1004A0003E170030BE1B013084000030BF1B0130FE

:1004B0003E2001390319BE13031DBE174008BF00BB

:1004C0003D08C000BC143C143C116400851FAC2ADC

:1004D000C830012064003C19712ABE013C10BC10D8

:1004E000AC2A03013E1C013E03193E10031D3E14BD

:1004F0000301BE1C013E0319BE10031DBE140301FF

:100500003E1D013E03193E11031D3E150301BE1D94

:10051000013E0319BE11031DBE1503013E1E013E1F

:1005200003193E12031D3E160301BE1E013E0319B0

:10053000BE12031DBE1603013E1F013E03193E13EA

:10054000031D3E170301BE1F013E0319BE13031D09

:10055000BE17BC103C103C116400051FB52A640096

:100560003C19B42A3C15B52A3C1170286300B62A00

:02400E00303F41

:00000001FF

Decodificadores BCD 7 segmentos

Dois esquemas de decodificadores BCD (de 0 a 9)  usando só portas de AND e OR de duas entradas e outro com o mínimo de portas lógicas.

Teste rápido para cpu 6809 e 68B09

Free run test para microprocessadores Motorola 6809 e 68B09:

Teste rápido de microcontrolador 80C31 e 80C32

Free run test para o microcontrolador 80C31 e 80C32:

Ampliação das escalas do voltímetro de alta impedância

Com apenas uma chave simples SPDT e um resistor é possível aumentar os fundos das escalas do meu voltímetro:

Dessa forma se altera as relações de ganho do amplificador operacional e amplio as escalas de medição.

Uma outra alternativa seria usar uma chave DPDT e dobrar os fundos das escalas: