[sebhc] New Heathkit H89 owner with many questions...

Bob Shannon bshannon at tiac.net
Mon Sep 25 19:56:12 CDT 2006

Hello Heathkit fans,

I've been collecting vintage computers for over 10 years, and I have a 
rather large collection of HP minicomputers
and a few other odds and ends.

Oh yeah, I have another Heathkit 'computer', sort of, I have a complete HERO 

I was just given a working, very clean H89 machine, with a single, worn, 
bootable floppy.
I'm trying to get up to speed on this machine, but I have limited 

Here's what I know:

This machine was used in the development of an array processor that was sold 
by Analogic Corp.
Its been sitting in the office of one of the senior engineers that been with 
Analogic for decades.

There are two half height floppy drives in the machine, and I have a single 
diskette.  The media
is clearly soft-sectored, and shows visible wear on several tracks.  I'm in 
fear of loosing my
only bootable diskette.

The machine boots HDOS, and DIR shows the following results:

NAME        EXT        SIZE        DATE

MBASIC    ABS        77            9-JUL-85
MDFAST    ABS        1            9-JUL-85
MDSLOW    ABS        1            9-JUL-85
SYSHELP    DOC        8            9-JUL-85
SYSLOGO   CMD        1            27-JUN-86
TEMPLATE    ASM        3         9-JUL-85
TEMPLATE    CC          2            9-JUL-85
VAX              ABS        1            9-JUL-85


No sysgen, not even a full distribution HDOS as far as I can tell.  I'm not 
at all sure
that I even have enough there to copy the one disk I do have.

MBASIC runs, 1977 Microsoft basic!  WooHoo.  Is there any documentation for
this on-line?  I cannot seem to recall how to save and load basic problems, 
I have written a few 'hello world' type programs that run just fine.

During the boot process some sort of modem device driver loads.

Oh yes, the machine reports 56K of ram installed.  The past owner told me 
the missing etch and being able to address more than 48K of ram.

I have not yet seen the interior of the machine, its sitting in my office at 
work (I also
work at Analogic).  I'll be completing the paperwork maze to get this 
machine off
the company books and back to my shop at home.

Ok, question time...

1. Can anyone here send me any bootable media for this machine?

2. Is it possible to know what disk controller I have installed without 
the machine up?

3. Can I switch from HDOS to CP/M 2.2?

4. What is the most practical way to get software and data onto this 

5. Is there some way to use an old PC with a 360K drive to write H89 media, 
or do I need
to use some sort of serial loader?

6. Is there any generic parallel interface option available?

7. Can MBASIC perform character I/O to a H89 serial interface?

8. I understand I cannot use SVD with my H89, (not hard sectored), is this 

9. Would it be more practical for me if I had a hard sectored disk 
controller and SVD?

Here are my plans for the H89..

First off, if I'm going to keep this thing, I think I'll replace the CRT and 
switch to a green
phosphor.  The stock tube is perfectly servicable, but it does have very 
slight screen burn
and re-tubing a Heathkit is a cakewalk.

I'd love to be able to tie the H89 to one of my vintage minicomputers.  The 
H89 could
serve as a combo console and mass storage system, either for one of my 
really old core
memory HP's, or for my ultra-rare Imlac PDS-1.

I'd need either a generic parallel interface, or I could build a serial to 
parallel interface dongle
to drive the paper tape reader interface on an HP.

I could tie the H89 directly to the serial interface on the Imlac, but the 
Imlac itself is actually
a smart terminal intended to tie into a larger (mainframe) system.  But I 
could store Imlac
software on the H89, and write a program to send the images out the serial 
port to boot
the Imlac.  It just seems a bit odd to have two machines that at least 
'look' like terminals
working together.  On the other hand, I would not need any parallel I/O for 

Any reccomendations?

Or should I keep using modern PC's to support vintage CPU's?

Delivered by the SEBHC Mailing List

More information about the Sebhc mailing list