Altair 8800

History

The MITS Altair 8800 (January 1975, Popular Electronics cover) is widely considered the first personal computer. Ed Roberts of MITS designed it around the Intel 8080 processor.

The kit sold for $395 (assembled $621). Within months, MITS was overwhelmed with 4,000 orders.

Gates and Allen

Bill Gates and Paul Allen saw the Popular Electronics article and contacted MITS, claiming to have a working BASIC interpreter for the 8080 (they did not yet). Gates wrote Microsoft BASIC for the Altair — their first product — in 8 weeks on a PDP-10 emulator.

This became Altair BASIC and launched Microsoft.

Replica / Emulator Access

Modern Altair emulators exist for various platforms. Connect with PuTTY:

Connection type: Serial
COM port: COM3 (or /dev/ttyUSB0 on Linux)
Speed: 9600 baud

CP/M on the Altair

CP/M (Control Program for Microcomputers) was the dominant OS for 8080/Z80 machines:

A>DIR           List files
A>TYPE file.txt Display file
A>COPY src dst  Copy file
A>ERA file      Erase file
A>STAT          Show disk statistics

Altair BASIC

10 PRINT "ALTAIR 8800 BASIC"
20 FOR I=1 TO 100
30 PRINT I
40 NEXT I
50 END
RUN