CREATE TABLE table_48787 ("System" CLOB, "Year Introduced" FLOAT, "S-100 slots" FLOAT, "Internal Floppy Disk" CLOB, "Internal Hard Disk" CLOB)

Which system introduced earlier than 1981 has an internal hard disk of 11 megabytes and less than 21 s-100 slots?
SELECT "System" FROM table_48787 WHERE "S-100 slots" < '21' AND "Year Introduced" < '1981' AND "Internal Hard Disk" = '11 megabytes'
SELECT "System" FROM "table_48787" WHERE "Internal Hard Disk" = '11 megabytes' AND "S-100 slots" < '21' AND "Year Introduced" < '1981'