The main reason I bought my Blizzard 1230+SCSI kit was to get the added 32 bit memory addressing capabilities of the full '030. The 'ec020 on the A1200 motherboard only has 24-bit addressing and therefore can only use up to 4 megs of fast RAM or 8-megs if you're not using your PCMCIA slot.
I've got 16 megs in my accelerator card mainly becuase if I added memory to the SCSI kit expander I'd be stuck with 70 nsec access time on all the memory instead of the 60 nsec I've got now. The speedup was sufficient to run Ultimate Doom at nearly full frame rate using ADoom. I used to have 32 megs of 70 nsec memory on board and was able to run Doom from memory by making a soft link to the wad file on the RAM: disk. That made it fairly playable.
