[sebhc] H89 docs

Dwight K. Elvey dwight.elvey at amd.com
Fri May 20 12:02:52 CDT 2005

 Why does one need to cut the schematic. Why not just
fold it?

>From: "Barry Watzman" <Watzman at neo.rr.com>
>Lee, it is the FCC class B that is the stricter standard.  And my
>recollection is that there are only two versions, that the Heath and Zenith
>"A" products are identical, and both meet class B.  The FCC made a ruling
>that all PCs had to meet class B, the tighter standard, regardless of the
>intended use or market.
>I would not suggest cutting the schematics apart.  The solution is a large
>format scanner.  Kinko's has these, but they charge $25 just to scan one
>page.  Richard Pestinger had University Library access to one of these and
>scanned the Z-100 schematics, perhaps he can do the same for the Z89
>schematics if he still has such access.
>Barry Watzman
>-----Original Message-----
>From: sebhc-bounces at sebhc.org [mailto:sebhc-bounces at sebhc.org] On Behalf Of
>Lee Hart
>Sent: Friday, May 20, 2005 1:46 AM
>To: sebhc at sebhc.org
>Subject: Re: [sebhc] H89 docs
>steve shumaker wrote:
>> What constitutes "late model" H89? (I recently acquired what I
>> think is a complete set of H89 docs). Model is 89A and the docs
>> are dated 1981.
>There are basically 3 versions: The original H89 (kit or assembled), the
>H89A (kit version), and the Z90A (assembled unit). Within each version,
>there were many variations, depending on what options were installed
>(which disk controllers, memory size, I/O boards, etc.).
>The original H89 (and H19 terminal) are recognizable by having 10-pin
>power connectors at the top left corner of the CPU and TLB boards (the
>large 11" x 10" boards at the back of the case containing most of the
>The H89A (and H19A terminal) are functionally identical, but have added
>shielding and filtering to pass FCC class A and B EMI standards. They
>can be recognized by having 11-pin power connectors (10 pins with one
>pin cut off) at the top left corner of the CPU and TLB boards.
>The Heathkit H89A and H19A versions have more shielding than the Zenith
>Z19A and Z90A versions, to pass the stricter FCC class A standards. The
>most obvious differences are large sheet metal plates bolted to the
>backs of the TLB and CPU boards in the Heath versions.
>If anyone need them, I have schematic and manuals for all of these. I
>would hesitate to have them cut apart for scanning, though they could
>probably be copied intact, as they lay flat when opened.
>If you would not be forgotten
>When your body's dead and rotten
>Then write of great deeds worth the reading
>Or do the great deeds worth repeating
>	-- Ben Franklin, Poor Richard's Almanac
>Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
>Delivered by the SEBHC Mailing List
>Delivered by the SEBHC Mailing List

Delivered by the SEBHC Mailing List

More information about the Sebhc mailing list