62256 was around $20 each in 1984 and that was over-the-counter retail costs with markup in the most remote city in the world -
8 of them would be 256K, and they had a low-power standby capability being SRAMs, where they would operate at 2v with a current as low as 22uA. So a small rechargeable battery would probably keep memory for several months, and certainly indefinitely with use at least monthly... A couple of AAs would have lasted for a few years.
Myke's idea uses this chip, so it wouldn't be that difficult to establish a battery backed ramdisk that would have cost less than $100 to make in quantity.
Also, CP/Ms disk structure has the nice feature that you can keep extending it until you run out of allocations or directory entries, which for a 256K memory, means you could sell it with 32K of memory - enough to boot from, and then keep on adding memory chips and tweaking the DPB to add more file space and the disk just grows - there are no partitions or File Tables to worry about or provision in advance.
So I like the way this project was built. If considered in this way, all the system files could be moved to the SDRAM, and the system booted from it, including any software frequently used, and disks just used for data, with backup system disks in case the RAM ever failed.
