H8 - 64K Memory expansion

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Mike Cassidy

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May 14, 2025, 8:02:15 AM5/14/25
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It has been suggested to me to upgrade memory in my H8 (thanks Glenn).  I'm planning on building the H8 64K RAM ORG0 card designed by Norberto.  The assembly instructions prepared by David Troendle are nicely written - I should be able to follow.  All of the parts listed in the bill of material are available.  I've been in contact with Cathy at OurPCB (very good to work with) and I can re-order at a very reasonable cost. I was not in a rush but now that tariffs are lowered temporarily I plan to go ahead with an order.  I'll be getting way more than one board for the minimum order cost so will be able to provide boards to others at very nominal cost.  

Before I hit send on the board order just looking to the group here for any advice or cautions.

Thanks

Mike   

Glenn Roberts

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May 14, 2025, 8:39:26 AM5/14/25
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It’s a great board. Should serve you well.

You might coordinate with Todd Goodman - he maintains an inventory of popular boards (I was surprised to see this board isn’t in his inventory?)
I can’t recall if the BOM references a rechargeable cell for the RAM backup but we have found that standard coin cells work fine and last a long time…

Sent from my iPad

On May 14, 2025, at 8:02 AM, Mike Cassidy <cmc...@gmail.com> wrote:

It has been suggested to me to upgrade memory in my H8 (thanks Glenn).  I'm planning on building the H8 64K RAM ORG0 card designed by Norberto.  The assembly instructions prepared by David Troendle are nicely written - I should be able to follow.  All of the parts listed in the bill of material are available.  I've been in contact with Cathy at OurPCB (very good to work with) and I can re-order at a very reasonable cost. I was not in a rush but now that tariffs are lowered temporarily I plan to go ahead with an order.  I'll be getting way more than one board for the minimum order cost so will be able to provide boards to others at very nominal cost.  

Before I hit send on the board order just looking to the group here for any advice or cautions.

Thanks

Mike   

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Mike Cassidy

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May 14, 2025, 10:30:08 AM5/14/25
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Todd was my first stop, but he does not stock the board. If all goes as planned, I will have a small inventory available.

Mike

Regards,

Mike Cassidy


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norberto.collado koyado.com

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May 14, 2025, 2:20:43 PM5/14/25
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Let me check if I do have any spare pcb boards.

From: se...@googlegroups.com <se...@googlegroups.com> on behalf of Mike Cassidy <cmc...@gmail.com>
Sent: Wednesday, May 14, 2025 7:29:51 AM
To: se...@googlegroups.com <se...@googlegroups.com>
Subject: Re: [sebhc] H8 - 64K Memory expansion
 

Mike Cassidy

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May 14, 2025, 3:15:18 PM5/14/25
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Thanks Norberto.  I did confirm the order at OurPCB.  So we'll have an abundance of boards available.

Mike

To view this discussion visit https://groups.google.com/d/msgid/sebhc/SA3PR01MB7918F4AB40ADC9945192B40EF791A%40SA3PR01MB7918.prod.exchangelabs.com.


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Regards,

Mike Cassidy

norberto.collado koyado.com

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May 14, 2025, 3:26:49 PM5/14/25
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I do have one board left that it replaces the board that you ordered: https://koyado.com/heathkit/New-H8-Website/h8-8080a-64kb-board.html

 

I need to verify this new board to add to Todd’s list.

 

Norberto

 

From: se...@googlegroups.com <se...@googlegroups.com> On Behalf Of Mike Cassidy
Sent: Wednesday, May 14, 2025 12:15 PM
To: se...@googlegroups.com
Subject: Re: [sebhc] H8 - 64K Memory expansion

 

Thanks Norberto.  I did confirm the order at OurPCB.  So we'll have an abundance of boards available.

 

Mike

 

On Wed, May 14, 2025 at 2:20 PM norberto.collado koyado.com <norberto...@koyado.com> wrote:

Let me check if I do have any spare pcb boards.

 

From: se...@googlegroups.com <se...@googlegroups.com> on behalf of Mike Cassidy <cmc...@gmail.com>
Sent: Wednesday, May 14, 2025 7:29:51 AM
To: se...@googlegroups.com <se...@googlegroups.com>
Subject: Re: [sebhc] H8 - 64K Memory expansion

 

Todd was my first stop, but he does not stock the board. If all goes as planned, I will have a small inventory available.

 

Mike

Regards,

 

Mike Cassidy

On Wed, May 14, 2025 at 8:39 AM Glenn Roberts <glenn.f...@gmail.com> wrote:

It’s a great board. Should serve you well.

 

You might coordinate with Todd Goodman - he maintains an inventory of popular boards (I was surprised to see this board isn’t in his inventory?)

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