Macintosh XL

Because of its roots as a Lisa — unlike all other Macintosh computers — the stock Macintosh XL used rectangular pixels. The resolution of Macintosh XL's 12-inch (30.5 cm) display was 720×364 pixels. Square pixels were available through the Macintosh XL Screen Kit upgrade that changed the resolution to 608×432 pixels.[4] The CPU could be replaced with a new CPU board containing up to 8 MB RAM, called XLerator 18.[5] The maximum upgraded RAM with conventional add-in RAM cards was up to 2 MB – quadruple the maximum capacity of earlier Macintosh computers. (With modifications to the CPU board, the XL could accommodate up to 4 MB of RAM).[6]

Despite its relative success, Macintosh XL was discontinued because it was unavailable. Parts had not been ordered to keep the XL in production, and once the last of the parts ran out, Apple made the decision to shut down production for good.[9] In 1986, Apple offered all Lisa/XL owners the opportunity to turn in their computer (along with US$1,498) and receive in exchange a Macintosh Plus and Hard Disk 20 (list price: US$4,098 at the time).[10]

After Apple dropped the XL from their price list in September 1985, Sun Remarketing of Logan, Utah, bought a number of Apple's remaining inventory and continued to sell them under license with their updated version of MacWorks Plus, re-branding it as Macintosh Professional.

Although no new Lisas were available for sale, development continued on MacWorks Plus to support the installed base of Lisas, making them as relevant as their closely-related cousin Macintosh Plus.

Macintosh XL shares the same legacy as Lisa before it. However, the increased sales from the emulation of the Macintosh operating system proved that the Macintosh family badly needed a more professional environment which could support larger monitors, greater memory, and more expandability than Macintosh 512K offered.