I made a few changes for this batch based on several years worth of feedback. First of all, previous purchasers should not feel left behind, as the changes are minimal, and would not be noticeable to the vast majority of vintage computer hobbyists. A person not aware of the specific change made would have to study the boards for a long time to find any difference. To give you the idea of the scope of the change, I’m calling this new version, “version 1.01″. I believe Mimeos have always been the best reproduction Apple 1 motherboards made, and this tweak raises the bar, just a little bit more.
What follows is summary of changes.
1) I changed the solder mask to matte. I’ve had a few people bugging me for years to do matte, and have finally been convinced to change. I did a matte run a few years ago on the Apple II rev 0, but thought the glossy look gave a superior “look”, though not quite as authentic. I have been doing glossy since then. Even a board made with matte solder mask will not exactly match with an original board, as PCB manufacturing technology has changed and is not possible to replicate exactly with modern processes. I suppose someone could attempt to replicate old manufacturing process, but keep in mind that many of the raw materials going into a PCB have changed since the 70’s, not just the solder mask. In any case, once you populate the board with components, the difference isn’t very noticeable. If I had to pick which bare board I was going to frame, I’d pick a glossy board, since it just looks a bit flashier. Be aware that he matte boards also look awesome, and will be a step closer to the original in appearance.
2) A few minor changes were made to the silk screen, to better replicate an original board. Some of these minor differences from the original were found by me and some reported by other people. Most of the differences I’ve known about, are so minor, that no one other than me, ever noticed them.
3) A few minor changes were made to the copper layer on the front. Same comments as with the silk screen layer.
4) The board grid coordinate numbering and lettering along the edges has been slightly reduced in weight, to better match to original.
5) Mounting holes were shifted ever so slightly to better match up with original Apple 1 mounting holes.
So here is a partial view the rev 1.01 PCB. Unless something unexpected happens, I expect that this will the last update for a long time.
Mimeo Version 1.01
Since I made changes, I need to assemble and test the new PCB before shipping PCBs. The good news is that the first board is up and running memory tests at this moment and testing should be complete by Tuesday. I should be able to accept orders starting on Wednesday and plan on shipping the first batch next Monday (10/14).
Just a note to those looking for assembled systems, this prototype Mimeo needs an enclosure and soon I’ll be working on the building a prototype enclosure for this unit. I’ve also been working on a custom datanetics style keyboard for fully assembled systems that will use modern components.