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Retrocomputing

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    With bank-switching the usage of large amount of memory is possible. I had 3 boards of 256K = 768K in my CP/M-3 Z80 machine in around 1982 or so. Mostly for ramdisk, but the O/S and the userspace was on different pages, leaving much more room for programs than CP/M2.2 Commented Nov 8, 2021 at 12:36
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    @Lenne That probably would have been 1983, as that was the year when CP/M 3 was released. Unmodified CP/M 2.x did not support bank-switching the OS out of the primary Transient Program Area, so the earlier systems would have had a TPA of somewhere around 40-50 KB TPA, as opposed to the 56 KB TPA that was easily achieved with CP/M 3. Either way, applications making effective use of more than 128 KB of RAM (after subtracting RAMdisk) would have had their own bank switching, or one would have used an MP/M system with multiple TPAs, one for each user. Commented Nov 8, 2021 at 14:20