In fall 2011, I acquired two Heath Zenith Z-150 systems. This preliminary page begins to describe them. This page last updated Aug 7 2012, (c) Herb Johnson all rights reserved. For other Heath/Zenith systems, check my Heath Zenith home page.- Herb Johnson
I was contacted in Oct 2011 with this email: "....I have 2 complete Zenith ZF148-42 computer systems in really good shape. The monitors are ZVM 1230 A, and I have one keyboard and the cables. We used them for the first computer writing lab in my college, in about 1982. They have been in my closet since the lab was updated. They were fully functional when stored. In fact, I had one of the Zeniths up and running last month. I hate to take them to the dump because I thought someday I'd find a computer person who would like to have them...." We arranged for a dropoff and pickup, and I acquired them sometime later.
Here's a photo of both systems, with the lone keyboard (XT type connector) and a Zenith monitor.
The two Zeniths powered up OK. One has a faulty floppy drive but both boot up MS-DOS. Here's a photo of the 360K floppy drive. That's a MS-DOS capacity of 360Kbytes, on 5.25-inch double-density diskettes. Very standard for the early 1980's. This machine ran MS-DOS in various versions - 3.2 was provided with this system.
I removed the faulty drive and transferred the second good drive to the system with 640K of memory. The other system had 256K of memory - it's a matter of adding sets of eight 256K X 1 DRAM chips to increase memory. Here's a photo of the motherboard. The memory is the three sets of rows of chips. It's easy to see the CPU and other major IC's, and the large amount of "logic" IC's which were used in the 1980's to operate the processor, memory, and I/O chips.
Here's a photo of the partially assembled system, with covers and the power supply as that large metal "box". the connectors on the rear, are for serial and parallel ports (printer, modem); a 9-pin connector for (probably) CGA color; and a small round "RCA" audio/video connector for the "composite video" which is what the pictured Heath monitor displays. These are green monochrome monitors and the display is 80 X 24 characters.
This class of computer was typical for the early post-IBM-PC-compatible era, of the mid-1980's, before the "Tiawan clone PCs" came to dominate the personal computing market.
- Herb Johnson
Copyright © 2012 Herb Johnson