Last night at the Seattle Commodore Computer Club
something really remarkable happened. With some ingenuity and skillful talent by group member Christian, we modified then witnessed an original Amiga 1000 Rejuvenator crank up to 2mb of chip RAM!
For this to happen we needed two things (in addition to the Rejuvenator
First and foremost we needed a highly coveted Fat Agnus found in the Amiga 3000: 8372AB (318069-03). I happened to have lucked into sourcing one last year early in 2018.
Secondly, we needed the RAM to support it. My Rejuvenator’s 8 RAM bays all utilized a very old and antiquated type of RAM not in production for probably twenty years or more. The original default 8@128k chips equal 1mb of total chip RAM. To reach 2mb totals, the needed chips are increased in size and staggered, thus only requiring 4 chips instead of 8.
Sourcing the old RAM is extremely unlikely. This is especially true if we want to try and build multiple boards in the future. Christian instead sourced a much more common DRAM chip in DIP format, which are much more plentiful and easily obtainable. To go this route, he had to solder the RAM to new adapter boards which required surface-mount soldering.
Going this route means regardless of future Agnus’ a user might have, the two types of RAM should be much more easily available - with the caveat that they would need to either solder their own adapters, or we create them pre-built. We’ll worry about logistics later - the great news is the RAM strategy WORKS
and should no longer be a potential major roadblock.
In addition to the RAM issue being resolved we’re still left with the possibility of changing the 2mb Agnus to a more easily found A600 variety, but we’ll worry about that later.
Now that the schematics are getting close to completion
we may very well be looking at printing some first-rev test boards in the next few months - which is amazing
I took some pics of the new working RAM, in addition to my Amiga 1000 seeing it just fine. Enjoy.
(In case the numbers confuse, I'm running a 256kb front expansion as well as an 8mb MKL fast RAM board, thus the bonkers 10+mb totals).