1977 and the emergence of the .22Trinity.22 History of personal computers

1 1977 , emergence of trinity

1.1 apple ii
1.2 pet
1.3 trs-80

1977 , emergence of trinity

by 1976, there several firms racing introduce first successful commercial personal computers. 3 machines, apple ii, pet 2001 , trs-80 released in 1977, becoming popular late 1978. byte magazine later referred them 1977 trinity . in 1977, sord computer corporation released sord m200 smart home computer in japan.

apple ii


apr. 1977: apple ii

steve wozniak (known woz ), regular visitor homebrew computer club meetings, designed single-board apple computer , first demonstrated there. specifications in hand , order 100 machines @ us$500 each byte shop, woz , friend steve jobs founded apple computer.

about 200 of machines sold before company announced apple ii complete computer. had color graphics, full qwerty keyboard, , internal slots expansion, mounted in high quality streamlined plastic case. monitor , i/o devices sold separately. original apple ii operating system built-in basic interpreter contained in rom. apple dos added support diskette drive; last version apple dos 3.3 .

its higher price , lack of floating point basic, along lack of retail distribution sites, caused lag in sales behind other trinity machines until 1979, when surpassed pet. again pushed 4th place when atari introduced popular atari 8-bit systems.

despite slow initial sales, apple ii s lifetime 8 years longer other machines, , accumulated highest total sales. 1985 2.1 million had sold , more 4 million apple ii s shipped end of production in 1993.

pet


oct. 1977: commodore pet.

chuck peddle designed commodore pet (short personal electronic transactor) around mos 6502 processor. single-board computer new display chip (the mos 6545) driving small built-in monochrome monitor 40×25 character graphics. processor card, keyboard, monitor , cassette drive mounted in single metal case. in 1982, byte referred pet design world s first personal computer .

the pet shipped in 2 models; 2001-4 4 kb of ram, or 2001-8 8 kb. machine included built-in datassette data storage located on front of case, left little room keyboard. 2001 announced in june 1977 , first 100 units shipped in mid october 1977. remained back-ordered months, , ease deliveries canceled 4 kb version next year.

although machine successful, there frequent complaints tiny calculator-like keyboard, referred chiclet keyboard due keys resemblance popular gum candy. addressed in upgraded dash n , dash b versions of 2001, put cassette outside case, , included larger keyboard full stroke non-click motion. internally newer , simpler motherboard used, along upgrade in memory 8, 16, or 32 kb, known 2001-n-8, 2001-n-16 or 2001-n-32, respectively.

the pet least successful of 1977 trinity machines, under 1 million sales.

trs-80


nov. 1977: trs-80 model i

tandy corporation (radio shack) introduced trs-80, retroactively known model improved models introduced. model combined motherboard , keyboard 1 unit separate monitor , power supply. although pet , apple ii offered features advanced in comparison, tandy s 3000+ radio shack storefronts ensured have widespread distribution neither apple nor commodore touch.

the model used zilog z80 processor clocked @ 1.77 mhz (the later models shipped z80a processor). basic model shipped 4 kb of ram, , later 16 kb, in main computer. expansion unit allowed ram expansion total of 48k. other strong features full stroke qwerty keyboard, small size, written microsoft floating-point basic , inclusion of monitor , tape deck approximately half cost of apple ii. eventually, 5.25 inch floppy drives made available tandy , several third party manufacturers. expansion unit allowed 4 floppy drives connected, provided slot rs-232 option , parallel port printers.

the model not meet fcc regulations on radio interference due plastic case , exterior cables. apple resolved issue interior metallic foil solution not work tandy model i. since model ii , model iii in production tandy decided stop manufacturing model i. radio shack had sold 1.5 million model i s cancellation in 1981.