Classic Mac OS memory management

<p>Historically, the <a href="/facts/Classic_Mac_OS/I5fQq44K">classic Mac OS</a> used a form of <a href="/facts/Memory_management/vthLkUpz">memory management</a> that has fallen out of favor in modern systems. Criticism of this approach was one of the key areas addressed by the change to <a href="/facts/MacOS/Y93vVpTm">Mac OS X</a>.
</p><p>The original problem for the engineers of the <a href="/facts/Macintosh_128K/oXlQGVpX">Macintosh</a> was how to make optimum use of the 128 KB of <a href="/facts/Random-access_memory/DuD4bxh6">RAM</a> with which the machine was equipped, on <a href="/facts/Motorola_68000/3p2wt2D6">Motorola 68000</a>-based computer hardware that does not support <a href="/facts/Virtual_memory/Lw2GemF5">virtual memory</a>. Since at that time the machine could only run one <a href="/facts/Application_software/YQuj7Kog">application</a> program at a time, and there was no <a href="/facts/Hard_disk_drive/kekLSGSE">fixed</a> <a href="/facts/Secondary_storage/wPHKFpdx">secondary storage</a>, the engineers implemented a simple scheme that worked well with those particular constraints. That design choice did not scale well with the development of the machine, creating various difficulties for both programmers and users.
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Classic Mac OS memory management open-in-new

Classic Mac OS memory management