CREATE TABLE table_203_136 (id NUMBER, "year" NUMBER, "ibm model number" CLOB, "name" CLOB, "processor" CLOB, "bus" CLOB, "hd interface" CLOB, "case" CLOB, "notes" CLOB)

which model was the first portable device ?
SELECT "ibm model number" FROM table_203_136 WHERE "case" = 'portable' ORDER BY id LIMIT 1
SELECT "ibm model number" FROM "table_203_136" WHERE "case" = 'portable' ORDER BY "id" FETCH FIRST 1 ROWS ONLY