CREATE TABLE table_63438 ("Processor" TEXT, "Model" TEXT, "Clock speed  ( MHz ) " FLOAT, "L1 cache  ( bytes ) " TEXT, "Introduced" TEXT, "Discontinued" TEXT)

When was the Lisa 2 model discontinued?
SELECT "Discontinued" FROM table_63438 WHERE "Model" = 'lisa 2'
SELECT "Discontinued" FROM "table_63438" WHERE "Model" = 'lisa 2'