Subscriber content previewA community of hobbyists is preserving the classic computers that helped launch the digital revolution. By TERRY CHEAAssociated PressAP Photo/Terry Chea [enlarge] A 1981 Commodore SP9000 “Super PET” computer and floppy disk drives are displayed at the Vintage Computer Festival this month. MOUNTAIN VIEW, Calif. — Software engineer Josh Dersch loves old computers. He spends countless hours tinkering in his garage, trying to coax decades-old machines back to life. He estimates he owns more than 200 vintage computers and devices in his Seattle home.