My First Post - Using an H-89A as a Terminal

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high...@lightspeed.net

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Sep 6, 2025, 1:07:15 AMSep 6
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I have been using and repairing older computers since the 90's. I just got my first Heathkit. I picked up an older computer made in 1976 a few weeks prior and started looking for a terminal. The H-89A just popped up and I bought it. I have lots of documentation for both machines. The early computer is an Electrical Products Associates Micro-68. It's well optioned with the required interface card, the original wood case with S-100 backplane, 64K RAM and PROM adapter. The terminal portion of the H-89A is working. I still need to get the computer section up and running. I'd love to get advice and suggestions from other who have used Heathkit terminals with other 8-bit computers. Ken

H-89a-01.jpgMicro68-01.jpgMicro68-02.jpgMicro68-03.jpgMicro68-04.jpgMicro68-05.jpgMicro68-06.jpg   

glenn.f...@gmail.com

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Sep 6, 2025, 7:21:23 AMSep 6
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Looks like a nice ’89. When you get a chance please share more pictures including internals. Since those are half-height drives I’m guessing you probably have a soft-sectored controller (the generic H89 came with a hard-sectored controller, Siemens FDD100 drive and was limited to 100K/diskette using hard-sectored disks.)

 

I’m guessing you’ve found SEBHC.ORG but if not take a look. There’s a pretty good archive there and also a wiki that is a little bit more current

 

I didn’t see a copy of the H88/89 service manual there, but may have missed it?  We should update the page, meanwhile here’s a copy that I’ve put in my Google Drive:

 

https://drive.google.com/file/d/1WxpEsdP82gN81mk8mVOaqcr8nuR7QkOP/view?usp=sharing

 

One of our members has also put together a bit of a war stories document on restoring systems (what worked, trip ups, etc.).  I’m guessing he’ll post that here. Not sure it has a home yet on The Net.

 

Meanwhile we’re here to help. There’s also a Discord server if you prefer where you can get more interactive and immediate information from experienced members of our group. Let me know if you’re interested and I can point you there.

 

Welcome!

 

  • Glenn

 

 

 

From: se...@googlegroups.com <se...@googlegroups.com> On Behalf Of high...@lightspeed.net
Sent: Saturday, September 6, 2025 1:03 AM
To: SEBHC <se...@googlegroups.com>
Subject: [sebhc] My First Post - Using an H-89A as a Terminal

 

I have been using and repairing older computers since the 90's. I just got my first Heathkit. I picked up an older computer made in 1976 a few weeks prior and started looking for a terminal. The H-89A just popped up and I bought it. I have lots of documentation for both machines. The early computer is an Electrical Products Associates Micro-68. It's well optioned with the required interface card, the original wood case with S-100 backplane, 64K RAM and PROM adapter. The terminal portion of the H-89A is working. I still need to get the computer section up and running. I'd love to get advice and suggestions from other who have used Heathkit terminals with other 8-bit computers. Ken

 

   

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G. Beat

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Sep 10, 2025, 4:02:23 PMSep 10
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Jeff Tranter has been posting a series of YouTube videos on the Heathkit H-89 computer.
He is up to Part 12, this week.
Here is Part 1.

gb
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