A-4 Microsoft Corp., Bellevue, Wash Purveyors of BASIC, MS-DOS, MultiPlan, Windows and Word.

A-12 Canada. Tempting target for U.S. hackers. Across-the-border hi-tech pacesetters include Northern Telcom.

A-13 Peterborough. N.H. Computer  magazine mecca. Offices of Byte, Popular Computing, and their rival, Wayne Green Publications.

B-1 Nippon-Japan Inc. Maker of 64K RAMs. NECs, SONYs and Epsons. Birthplace of Pac-Man and Donkey Kong.

B-3 Walden Software, Sunny Valley, Ore. Cottage of Paul Lutus, mountaintop developer of Apple Writer and GraFORTH.

B-9 Milwaukee, Wise. Whence “414" (the local area code) hackers fanned out across network America for fun and knowledge.

B-13 Rte. 128, at top of Silicon Alley. World center for minicomputers and dedicated word processors.

B-15 pBoston, Mass. Home of Comuter Museum, M.I.T. Logo Lab, and Harvard dorm room where MBASIC was written.

C-1 San Francisco, Calif. Locale of West Coast Computer Faire and countless conventions, conclaves and cookeries.

C-4 Homestead High School, Cupertino, Calif. Where Apple cofounders Steve Jobs and Stephen Wozniak first met for pranks and profits.

C-5 On-Line, Software, Coarsegold, Calif. Publishers of arcade-style games, graphics adventures and Home Word.

C-11 CompuServe Information Service, Columbus, Ohio. On-line CB Simulation, Special Interest Groups and Megawars, plus news and weather.

C-12 Wang Laboratories, Lowell, Mass. Top supplier of dedicated word processors; also, Wang Writer and Professional Computer.

C-13 Digital Equipment Corporation (DEC), Marlboro, Mass. Principal producer of minicomputers; also, Rainbow 100 and DECmate II.

C-15 Timex computers. Best-selling Timex/Sinclair 1000 and highly rated Timex 2068 stilled by closing of watchmaker's computer division.

D-1 Apple Computer, Inc., Cuper tino, Calif, founded January 3, 1977. Home of Apple II, Apple III, Lisa and Macintosh.

D-5 Homebrew Computer Club. Cradle of SOL, Apple II and Osborne computers, and countless baby millionaires.

D-6 Santa Clara County, Calif., a.k.a. Silicon Valley. From Palo Alto to San Jose; home of legendary garages and hot tubs.

D-9 Chicago, Ill. Headquarters of arcade games maker Bally-Midway: also, Mother's tavern, where new video games are tested.

D-11 Commodore International, Wayne, Pa. Manufacturer of 6502 Microprocessor, Commodore VIC-20 and Commodore 64.

D-15 Coleco Industries, Inc., West Hartford, Conn. Creators of ColecoVision and Coleco Adam.

E-1 Processor Technology. After SOL, the first typewriter-style computer, company faced lawsuits over faulty disk drives and dissolved.

E-13 IBM, Armonk, N.Y Corporate HQ of the world's largest computer maker. Home of THINK and dark suits.

E-15 New York City, in the heart of Silicon Alley. World headquarters for finance, mass media and the Lunch Group.

F-2 IMSAI. Only est-based personal computer firm foundered while designing a follow-up to its successful first machine.

F-2 Osborne Computers. Creators of first portable computer and first major bankruptcy in personal computers.

F-3 Atari Inc., Sunnyvale, Calif. Incorporated June 27, 1972. Makers of classic video games and Atari Home Computer line.

F-4 Androbot, Inc., Sunnyvale, Calif. Since 1983, purveyors of home robots. Current mode: BOB and TOPO.

F-7 The Sphere Computer. First desktop all-in-one with monitor never worked right, then expired when its designer left the company.

F-12 ENIAC. Remains of first electronic computer stand at Moore School of Electrical Engineering in Philadelphia.

F-13 New Jersey. Nation's most industrial state. Where Bell Labs conducts research into speech synthesis.

F-14 Dow Jones News Retrieval  Service, Princeton, N.J. Electronic Wall Street Journal, Grolier Encyclopedia, sports news and financial data.

G-3 Hollywood. Where computers help create special effects for silver screen and turn movies into video games.

G-5 US Festivals. Apple Computer whiz Stephen Wozniak's attempts to bridge gap between ROMs and rock.

G-13 The Source, McLean, Va. Athome shopping, electronic mail, self-publishing, airline schedules and other pertinent data.

G-14 Washington, D.C. District of computers for SSI, IRS, FBI, CIA and DOD, among others. Home of Smithsonian computer exhibits.

H-7 Altair. First personal computer company, MITS, sold out to Pertec conglomerate, condemning Altair 8080 to slow death.

H-8 Las Vegas, Nev. Hot spot for consumer electronics and computer industry trade shows with glitz.

H-11 Texas Instruments. Lubbock, Tex. Makers of TI Professional Computer and late, lamented TI 99/4A.

I-8 Tandy Corp./Radio Shack, Ft. Worth , Tex. Manufacturers and retailers of TRS-80 Models II , 4, 16, 100, and Tandy 2000.

I-16 IBM Entry Systems Division. Boca Raton, Fla. Originators of IBM PC, XT, AT, PCjr and Portable PC.

J-7 Redwood City, Calif. Where Dr. John Lilly communicated with dolphins via Apple II computers.

J-9 Mexico. Ever more U.S. computers assembled across Rio Grande, while Mexican government frowns on computer imports.