CSPPC in mine with all RAM on it, 128MB worth, A4000 came with a 880kb drive as well, A300 and A4000 BOTH had the HD drive as an option, the RAMSEY and DMAC are fine, I NEVER botherd to change mine and NEVER had an issue at all. I know most poeple didnt have any. For the hell of it I put in the last Ramsey with my old DMAC to see what it would do. It works fine and they dont have to be upgraded in a pair like
this is not exact. Almost every A4000, if not all, were shipped with Hi density floppy drive (1760 Kb) and a IDE HD (min. 120M).
You have to change RAMSEY and DMAC either if you want to use the Page-detect mode with static column RAM, which may give you faster access or if you want to use certain cards designed for A4000, for example the crappy C= 3640.
Dave Haynie said many times that Ramsey and DMAC should be changed in pairs ( either you have Ramsey 04 and DMAC 02 or Ramsey 07 and DMAC 04). Maybe a mixed pair can work in some circumstances, but do you trust it works for everyone?