Help! ID this Zenith computer

From: Christian Fandt <>
Date: Sat Sep 25 10:24:23 1999

Upon the date 11:00 PM 9/24/99 -0700, Zane H. Healy said something like:
>>I went scrounging again today and brought home a large Zenith computer.
>>Model number ZDF-121-32. It's about 18" wide and 14" tall and has an
>>attached keybaord. It has two 5 1/4" floppy drives on the RH side of the
>>front and a ~12" monitor on the LH side. Can someone tell be what it is and
>>what kind of OS it uses? I also need OS, software and manuals if anyone
>>has them.
>> Thanks,
>> Joe
>I want to say a Z-89. All one piece right? Let me guess, Military surplus
>again? I think it ran CP/M, in fact I think my set of CP/M manuals is from
>one of those systems. I've not seen one in about eight years, and never
>used one, so don't really know anything about them. I know the Navy used
>them as administrative computers on shore, I never saw them on ship, but
>that doesn't mean a few didn't make it there. Don't know how popular they
>were elsewhere.

It's actually a version of the good ol' Z100 dual processor all-in-one
computer. The Z100 was introduced just a hair before the ubiquitous PeeCee
model 5150 was introduced in '82. Had a broad following especially since
the US military bought thousands of them over several years. Came with
M$DOS and CP/M-85 (processors were 8088 and 8085). Expansion bus was S100
which was a great feature IMO.

As usual with Heath, virtually all tech info was available including ROM
listings therefore a lot of third-party suppliers sold additions and
enhancements. I've still got a couple of ZF-110 models here which were the
lo-profile units without built-in display.

The PeeCee freight train got rolling along at great speed thus running the
Z100 machines off the tracks into oblivion :( Much too bad because the
Z100 family had fundamentally better capability than a stock PeeCee: was
'open' by virtue of all docs available and S100 expansion and had begun
initially to have a broad following because of the third-party
applications, hardware, government purchase contracts and finally,
follow-on purchases by previous H89/Z90 owners who could run much of their
software on the Z100 under CP/M-85.

Oh well.

Regards, Chris
-- --
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA
        Member of Antique Wireless Association
Received on Sat Sep 25 1999 - 10:24:23 BST

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