From the Aer Lingus Amchlar an tSamraidh 1989 (Summer timetable) - the deployment of the 1-11s looks very patchy and the timetable can't be totally accurate as there is a daily Cork-Heathrow flight on a 1-11 but no return; a daily Heathrow-Dublin 1-11 but no means of moving the aircraft between Dublin and Cork.
EI712 ORK 1325 - 1440 LHR daily
EI846 DUB 1240 - 1625 AMS -----6- 03Jun30Sep
EI642 DUB 0745 - 0840 BHX 12345--
EI262 DUB 1100 - 1155 BHX -----67
EISN642 DUB 0745 - 1115 BRU 12345--
EI846 DUB 1240 - 1320 ORK -----6-
EI698 DUB 1615 - 1855 DUS 12345-7
EI652 DUB 1030 - 1330 FRA 1234567
EI458 DUB 1800 -1920 LGW 1234567
EI680 DUB 0710 - 0755 MAN 12345--
EI214 DUB 1535 - 1620 MAN ------7 04Jun24Sep
EI216 DUB 1830 -1915 MAN -----67
EI218 DUB 1905 - 1950 MAN 12345-7
EI083 DUB 1245 - 1320 SNN 12345--
EI659 DUB 1600 - 1635 SNN -----67
EI097 DUB 2200 - 2235 SNN 12345-7
Cork-Manchester back in those days was twice weekly on a Shorts 360. Cork-Birmingham had twice-weekly Sat/Sun services but one was a Fokker 50!