BTW - anyone invested in this project such as @techknight, @maceffects, @quorten, @asicsolutions, @cheesestraws and anyone who has been sent a rev 1.4c board - please join the Retro Tinkering Discord: https://discord.gg/8dJxmF8Tzh - easier to chat in there about things to save this thread from getting too cluttered!
Hmm those EN64K's...they could be 6264 SRAM? Either that, or bus transceivers - they seem to be connected to the data bus...?
@maceffects For the BBU - i'd be willing to stump up a spare BBU - FOR THE CAUSE. As well as the $. I'm due to cash in some stock options again this year to put down a 20% house deposit - i can spare $1000 for this.
Regarding the plug in board - tbh, i'd map out the schematic of it - then i'll make a board design based on it - with SOIC parts, still, but with a SMD PLCC socket for the CPU. For SOIC - you can hand solder these parts, no need to use hot air.
Actually on Paper the 68000 supports up to 16Mb of RAM...@Kai Robinson they look lovely. Excuse my potential ignorance, but isn’t the SE limited to 1mb SIMMs? And if I recall many Macs of this era didn’t like 3 chip memory SIMMs. If you think we have a way to allow more memory, I’d be very keen on learning more.
Technically the board/chip could be X-Ray'd... There is also tracing software these days that help trace the board lines out & identify ICs...@maceffects It's also useful to reflect upon Brainstorm's historic business model, which was to first reverse engineer the Macintosh Plus PALs and then use that knowledge to create the Macintosh SE BBU replacement. I'd reckon that method on its own must have created pretty good results. As far as reverse engineering the Brainstorm is concerned, most of our efforts should really just be focused on analysing the software of the embedded 68k processor on the PDS. I'd guess the Brainstrom BBU is not an FPGA and has no firmware of its own and the firmware upgrade only goes toward the embedded 68k processor, but maybe it is actually used as a loader for the BBU that's just an FPGA.
Well, either way, my two cents, there's nothing interesting to see by destructive reverse engineering of the Brainstorm BBU directly.