Micro Instrumentation and Telemetry Systems (MITS) ALTAIR 8800

This system was donated by Neil Frieband. It was purchased as a kit, and assembled by a technician at Incoterm.

Serial Number 224019K. The "K" at the end of the serial number usually means that it was sold as a kit. From the date codes on the boards, it looks like this system is from early 1976.

The MITS Altair 8800 was designed in 1974 by Ed Roberts and Bill Yates at MITS in Albuquerque, New Mexico. It is based on the Intel 8080 CPU and the backplane is the S-100 bus. The Altair was featured on the cover of the January 1975 issue of Popular Electronics, and was sold by mail order. The designers were surprised when they sold thousands of the kits in the first month. Altair BASIC for this machine was the product that caused Microsoft to really grow.

This system has had the Grounding Modification performed that connects Logic Ground to Chassis Ground in many places. It has the one piece 18-slot backplane PCB, instead of the earlier multiple 4-slot backplanes.

We have binary images of 16K BASIC for this system. The plan is to program eight 2708 EPROMs with the BASIC images and then run BASIC from the EPROMs. We can then save and load BASIC programs to/from paper tape on the Teletype.

It would be nice to know where this serial number falls in the production range.

The "K" at the end of the serial number means that it was sold as a kit.

The boards from the foreground to the background are:

  • MITS 8080 CPU

  • MITS 4k Dynamic Ram

  • Cromemco Bytesaver

  • 88-2 Serial I/O

  • MITS 4k Dynamic Ram

Updated board configuration

  • MITS 8080 CPU

  • Godbout EconoRAM VII 24( kB, 0x0000-0x5FFF)

  • 88-2 Serial I/O (20 mA current loop)

  • Cromemco Bytesaver (MITS 8k BASIC)

Click on the image for a larger view.

Only one of the serial ports on the 88-2 Serial I/O board.

The large electrolytic capacitor was added to the +8V by the owner.