The concept is old as the hills, if you include static RAM. It was a common way for early digital synthesizers (early 80s) to store patches in battery backed SRAM. Even on removable cards.
My first encounter with the concept was in 1982 during the summer working at an electronics company. We used the then new 64K DRAMs in production so there was a ready supply of devices vendors had given us for evaluation. I built a 128KB memory board with bank selection logic then wrote a driver for the Flex OS (6809) to make that memory appear like a disk. Also built a similar board with (probably, long time ago..) 27128 eproms that worked as a "ROM-Disk". I doubt I invented the ram disk. I'd probably heard of the idea somewhere, but I hadn't actually seen an implementation before the one I made.
The next year I switched to a larger company for summer work (defense contractor) and there wrote a driver for CP/M that talked to a "server" I wrote running on their VAX (via 19.2K serial). It made a large file on the VAX look like a disk to CP/M. We used this arrangement for backup -- copy all the files from the physical hard drive to the remote drive. Again I don't believe I'd seen this done before but it was a fairly obvious extension of the previous ram disk idea.
Unfortunately it turned out the group I worked for got billed by the computer dept for CPU time and I/O on the VAX and my network attached storage scheme ran up a huge bill so had to be abandoned.
> I built a 128KB memory board with bank selection logic then wrote a driver for the Flex OS (6809) to make that memory appear like a disk.
Oy! I could have written exactly that. What a coincidence :-) I also wouldn't claim invention. Maybe I heard of it, but I'd say the idea is pretty obvious.
We made it possible for Flex to run to programs simultaneously and also do print spooling.
(That's when I bought an HP 16C. Great help. Still have it.)
The concept is old as the hills, if you include static RAM. It was a common way for early digital synthesizers (early 80s) to store patches in battery backed SRAM. Even on removable cards.
My first encounter with the concept was in 1982 during the summer working at an electronics company. We used the then new 64K DRAMs in production so there was a ready supply of devices vendors had given us for evaluation. I built a 128KB memory board with bank selection logic then wrote a driver for the Flex OS (6809) to make that memory appear like a disk. Also built a similar board with (probably, long time ago..) 27128 eproms that worked as a "ROM-Disk". I doubt I invented the ram disk. I'd probably heard of the idea somewhere, but I hadn't actually seen an implementation before the one I made.
The next year I switched to a larger company for summer work (defense contractor) and there wrote a driver for CP/M that talked to a "server" I wrote running on their VAX (via 19.2K serial). It made a large file on the VAX look like a disk to CP/M. We used this arrangement for backup -- copy all the files from the physical hard drive to the remote drive. Again I don't believe I'd seen this done before but it was a fairly obvious extension of the previous ram disk idea.
Unfortunately it turned out the group I worked for got billed by the computer dept for CPU time and I/O on the VAX and my network attached storage scheme ran up a huge bill so had to be abandoned.
If you like FlexOS you'll like this Youtube channel: https://www.youtube.com/user/deramp5113/videos
As for me it's a bit before my time. I started out writing device drivers for Microware OS-9 on 68k.
> I built a 128KB memory board with bank selection logic then wrote a driver for the Flex OS (6809) to make that memory appear like a disk.
Oy! I could have written exactly that. What a coincidence :-) I also wouldn't claim invention. Maybe I heard of it, but I'd say the idea is pretty obvious. We made it possible for Flex to run to programs simultaneously and also do print spooling. (That's when I bought an HP 16C. Great help. Still have it.)
Also some early general-purpose microcomputer products in early '80s:
http://s100computers.com/Hardware%20Folder/SemiDisk/History/...
http://s100computers.com/Hardware%20Folder/Electralogics/His...
The original GameBoy cartridges often used battery backed SRAM for savegames.
I don't personally, because battery backed SRAM is a poor man's eeprom.