View Full Version : Mark8

April 25th, 2013, 12:56 PM

I've really enjoyed reading this forum over the years and marveling at the collected knowledge.

I have been slowly collecting parts to build a Mark 8 replica, not a very powerful or complex machine but most definitely a learning experience!
I now have most of the IC's but I couldn't find a set of boards. On Bryan's excellent Bytecollector website, http://bytecollector.com/mark_8.htm, is a high quality scan of the article in Radio Electronics so I hatched a plan....
I extracted the pictures from the pdf, rotated, aligned and stacked all the layers in Photoshop and cropped them to the correct size (the article doesn't show the board outlines). Each board top & bottom copper layers were then imported into Eagle (layers 201 and 202 in my files) for each of the boards. The circuit diagram was captured and the imported lines used as guides to route the tracks.
The finishing touches of the text and markings in the copper were added as well as tidying up the component names if a silkscreen is to be printed.

In the spirit of sharing knowledge and hopefully to encourage others to build replicas I will post the full Eagle design files and Gerbers I have created.
This is my first attempt at reverse engineering something this complex plus I have not taped out the boards yet to check they work, so they will need to be checked. The ERC and DRC does throw up errors but they are all trivial ones. Once I have finished them all I will send them off to be made for my build.
I won't claim I've made a perfect job of them, but I believe they are good enough to fool most people. (I have corrected two of the known errors, but sympathetically I hope)

The link to the Eagle layout, Gerbers etc for the CPU card, is here.
When I finish the other boards I will post them.

I would welcome any comments / suggestions....
(Can someone suggest a better place to host the files?)


April 28th, 2013, 10:42 AM
There is a new yahoo group, called retro-restore, in which you can share ideas with like minded people. There also is a files section, in which you can share your files. Subscribe through this link.

Mike Willegal

April 30th, 2013, 05:21 AM
Thank you for the link Mike. I have applied to join and I will introduce myself and post the files there.