To answer your questions Macflyer, the Mac SE can address up to 8MB of RAM, provided you have a Processor Upgrade Card for the SE. It was a PDS expansion card that piggy-backed on top of the original stock Logic Board. You would have 4MB RAM on the stock Logic Board and 4MB RAM on the Processor Upgrade Card. Technically, it was called an accelerator card or expansion card. Some of these cards featured a 68020 or even a 68030 processor in addition to the more RAM.
The SE and the SE/30 are 100% compatible in power supplies, analog boards, CRT and logic boards. You can swap out the parts without fear of incompatibilities. I have already done this myself with my SE. When my SE logic board's ADB ports stopped working, I bought an SE/30 logic board from user MacG4 and replaced logic boards with no issues. It gave me a faster processor (68030 16 Mhz vs. 68000 8 Mhz) and I can install up to 128 MB RAM max total. The only minor difference is that the SE/30 upgrade does generate more heat, due to a faster more powerful processor and the 68882 chip.
73s de Phreakout.
The SE and the SE/30 are 100% compatible in power supplies, analog boards, CRT and logic boards. You can swap out the parts without fear of incompatibilities. I have already done this myself with my SE. When my SE logic board's ADB ports stopped working, I bought an SE/30 logic board from user MacG4 and replaced logic boards with no issues. It gave me a faster processor (68030 16 Mhz vs. 68000 8 Mhz) and I can install up to 128 MB RAM max total. The only minor difference is that the SE/30 upgrade does generate more heat, due to a faster more powerful processor and the 68882 chip.
73s de Phreakout.