Thanks - I'm going to order a set of prototypes boards as soon as you're ready 
to share. Will anything in the parts list change?

[cid:32f88c46-e6bc-44d1-a531-143b90c69e50]

//Ken S.
________________________________
From: M100 <m100-boun...@lists.bitchin100.com> on behalf of Stephen Adolph 
<twospru...@gmail.com>
Sent: Wednesday, November 29, 2023 1:13 PM
To: m...@bitchin100.com <m...@bitchin100.com>
Subject: Re: [M100] Model T clock doubler

Had to do a minor responsibility!  Will post in a week.

On Wednesday, November 29, 2023, Ken St. Cyr 
<k...@stcyrfamily.net<mailto:k...@stcyrfamily.net>> wrote:
Hey Steve -

I went to grab the gerbers from the upgrade page in the wiki, and the links 
aren't working. Would you mind sharing the file for the M100 board?

Thanks!
//Ken S.
________________________________
From: M100 
<m100-boun...@lists.bitchin100.com<mailto:m100-boun...@lists.bitchin100.com>> 
on behalf of Stephen Adolph <twospru...@gmail.com<mailto:twospru...@gmail.com>>
Sent: Saturday, November 18, 2023 10:54 AM
To: m...@bitchin100.com<mailto:m...@bitchin100.com> 
<m...@bitchin100.com<mailto:m...@bitchin100.com>>
Subject: [M100] Model T clock doubler

Hi everyone,

I've been working towards finishing off my project for increasing the speed of 
the Model T laptops.  The idea is to create a (relatively) easy to make and 
install solution that allows the user to switch the clock rate from 2.5 MHz to 
5 MHz.
This is really nice on the 40x8 LCD machines.

The universal software command to switch clock rate is
OUT 85,1 for 2x mode and
OUT 85,0 for 1x mode.

Of course the Model T is not designed for this, but in my experience so far, it 
seems reliable.  I really like the upgrade and plan to install in all my 
laptops. Being able to operate in nominal clock mode is of course very useful 
because you may find some software to be incompatible.

Models I have upgraded to date:
* M100 (NA, early variant, not UK)
* T102
* T200
* NEC PC-8201/8201a
* Olivetti M10

I am publishing all the information needed to DIY this upgrade. I don't have 
any plans to make these upgrades.  Consider this upgrade only if you are 
comfortable with soldering surface mount parts, and with making minor 
modifications to your laptop.

Upgrades that are done and in the process of documentation are M100, T200, NEC. 
 Upgrades that need a new PCB design still are T102 and M10.  All information 
will be at this site:

https://bitchin100.com/wiki/index.php?title=5MHZ_upgrade_for_Model_T

I am publishing
* PCB designs for the clock doubler board (there are a few variants)
* schematic
* bill of materials for parts you need
* documentation for building the clock doubler
* installation documentation per laptop

Things I have discovered while developing this;
1.  Power consumption goes up by about 20% when you run at 2x clock.
2.  Depending on the speed of your SRAM,  you may need to implement a 
modification to speed that up.  Each model has a specific mod you need.
3.  In M100 with the custom socket pinout, in most cases you need to upgrade 
your Main ROM to something faster.  This usually involves an adapter board and 
an EPROM.
4.  In the Tandy 200, one must slow down the machine temporarily to access the 
RTC.  There is a specific change for that.

Anyhow, as I complete a particular laptop, I'll post the needed files.

Hopefully this will be of some interest for those inclined to play around with 
hardware.  I have no problem if anyone wants to take the design and improve it 
or change it.

Feel free to contact me directly with questions.

cheers
Steve




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