I still have some pcb's etc from the run of these I did back in 2013.
As is the case for most of us, life interferes at times and forces us
into alternate directions.
I would have to look but somewhere is the drive I had all the original
PCB design files stored on. If anyone is tech savvy enough all the
info needed to create a new version of the cart is in the files section
of the group.
When reverse engineering the original I shifted to a lithium memory
retention design rather than the original nicad based setup. I would
be interested to know how long the memory was retained as this was
my greatest concern and at the time suggested the battery be changed
every couple of years. Simply required unscrewing the case, plugging it
into the SDS and swapping the battery out for a new one.
I really was not sure how long the lithium would last. One of the biggest
issues is that you cannot use more recent memory chips. I had to dig
up new old stock as the transfer timing etc is fairly critical for the cart to
work. I tested so many combinations of RAM chips with various write timings
but found only the older types of ram were reliable. This took considerable
time and as I found the early hard to come by ram was not cheap.
Even then when putting them together with new old stock ram, I had about
a 20% failure rate on initial testing and this required some mix and matching
get each cart to be reliable - at least for those who got carts in 2013 you can
be assured each one was rigorously tested on an individual basis.
Long story short I can try to help out if someone wants to give it another
go but due to other life priorities at the moment I really could not invest
the time required to do another run sadly.
Richard