Microsoft KB Archive/34220

Description of the Heath/Zenith 150/151 Computers PSS ID Number: Q34220 Article last modified on 09-23-1991 PSS database name: PSS

Summary:

The Heath/Zenith 150 and 151 computers are the same machine. The 150 is the earlier version. A Heath is the same as a Zenith, except that it was assembled from a kit, instead of being purchased preassembled.

More Information:

Zenith changed the name of the 150 to 151 when they introduced the 156, 158, and 159 computers, so that they could refer to the series as 150.

Some 151s have the ROM BIOS Version 3.00 or later, while all 150s and early 151s have a Version 2.x. If the ROM BIOS is upgraded, the 150/151s work correctly with many products with which they previously did not, such as the Microsoft MACH 20 and Microsoft Windows Version 2.03.

These machines contain a built-in CGA card, which contains part of the CPU circuits; therefore, a disabling kit for video cards is required if the user wants to install a different video adapter. Another difference from the IBM standard that can cause some hardware interference is that COM1: uses interrupt level 6 instead of 4.

Copyright Microsoft Corporation 1991.