| Machine | Company | Location | Installed |
|---|---|---|---|
| Leo III/1 (s) | Leo Computers Ltd, Bureau machine |
Hartree House Queensway, London |
1962 -1972 |
| Leo III/2 (s) | Leo Computers Pty | Johannesburg, SA | 1962 -1972 |
| Leo III/3 (s) | Dunlop Rubber Co. Ltd. then to BOC |
Birmingham | 1962 -1966 |
| Leo III/4 (s) | London Boroughs Joint Computer Committee |
Greenwich | 1963-1975 |
| Leo III/5 (s) | CAV Ltd. | London | 1963-1971 |
| Leo III/6 (s) | Shell-Mex & BP Ltd | Hemel Hempstead / Manchester | 1963-1972 |
| Leo III/7 (s) | J. Lyons & Co. Ltd. | London | 1963-1972 |
| Leo III/8 (s) | Tubemakers Pty. Ltd | Sydney, Australia | 1963-1976 |
| Leo III/9 (s) | HM Customs & Excise, | Southend | 1963-1974 |
| Leo III/10 (s) | Board of Trade | Eastcote | 1963-1971 |
| Leo III/11 (s) | Smith & Nephew Ltd | Birmingham | 1963-1970 |
| Leo III/12 (326) | Leo Computers Ltd, (experimental 326 m/c.) |
Minerva Road, Acton |
1963 -1967 |
| Leo III/13 (s) | BOC Ltd, | Manchester | 1964 -1975 |
| Leo III/14 (s) | Shell-Mex & BP Ltd. | Hemel Hempstead / Manchester |
1964 -1972 |
| Leo III/15 (s) | Shell Australia | Melbourne | 1964-1969 |
| Leo III/16 (s) | Kayser Bondor Ltd. | Baldock | 1964-1971 |
| Leo III/17 (s) | Manchester Corporation | Manchester | 1963-1975 |
| Leo III/18 (s) | Cerebos Ltd. then BOC | London / Manchester | 1964-1978 |
| Leo III/19 (s) | DNS (GPO) then London Boroughs MSU |
Lytham St Annes London |
1964-1966 1967-1974 |
| Leo III/20 (s) | Colonial Mutual Life | Melbourne, Australia | 1964-1973 |
| Leo III/21 (s) | Tote Investors Ltd. | London | 1964-1973 |
| Leo III/22 (s) | H. J. Heinz & Co. Ltd. then Renolds Chains |
London Manchester |
1964-1971 1971-1975 |
| Leo III/23 (360) | Dunlop Rubber Co. Ltd, then Freemans Ltd. |
Birmingham London |
1965 -1971 1971-1973 |
| Leo III/24 (s) | Allied Suppliers Ltd., then Phoenix Assurance Co. |
London | 1965 -1970 1970-1973 |
| Leo III/25 (s) | Inland Revenue | Worthing | 1965 -1974 |
| Leo III/26 (326) | NDPS (GPO) | London | 1965-1980 |
| Leo III/27 (326) | Freemans Ltd. | Stockwell, London | 1965-1975 |
| Leo III/28 (s) | Coventry Corporation | Coventry | 1965-1972 |
| Leo III/29 (360) | Shell Mex & BP Ltd. | Manchester / Hemel Hempstead |
1965-1975 |
| Leo III/30 (s) | Royal Bank of Scotland | Edinburgh | 1965-1975 |
| Leo III/31 (360) | Shell Mex & BP Ltd. | Hemel Hempstead | 1965-1975 |
| Leo III/32 (s) | Colvilles Ltd. | Motherwell | 1965-1974 |
| Leo III/33 (s) | Phoenix Assurance Co. | Norbury, London | 1965 -1973 |
| Leo III/34 (326) | NDPS (GPO) | London | 1965 -1977 |
| Leo III/35 (s) | South Western Gas Board | Bath | 1965 -1973 |
| Leo III/36 (326) | DNS (GPO) | Lytham St Annes | 1966-1975 |
| Leo III/37 (s) | British Insulated Callenders Cables | Prescot | 1965-1972 |
| Leo III/38 (s) | HM Dockyard | Portsmouth / Rosyth | 1965-1977 |
| Leo III/39 (s) | Ever Ready Co. (was NDPS III/90) |
London | 1965-1973 |
| Leo III/40 (s) | Consolidated Glass | Germiston, South Africa | 1966-1973 |
| Leo III/41 (360) | NHKG | Czechoslovakia | 1966-1977 |
| Leo III/42 (s) | Renold Chains Ltd | Manchester | 1965-1974 |
| Leo III/43 (360) | HM Dockyard (replaced LEO III/38) |
Portsmouth | 1966 -1977 |
| Leo III/44 (326) | NDPS (GPO) | Cardiff & London | 1966 -1981 |
| Leo III/45 (s) | Wedd Durlacher Mordaunt | London | 1966 -1972 |
| Leo III/46 (326) | J. Lyons & Co. Ltd, then NDPS (GPO) |
London | 1966-1972 |
| Leo III/47 (326) | UDZ | Czechoslovakia | 1966-1980 |
| Leo III/48 (s) | HM Dockyards, | Devonport | 1966-1977 |
| Leo III/49 (326) | Shell Australia | Melbourne | 1966-1972 |
| Leo III/51 (326) | NDPS (GPO) | Edinburgh & London | 1966 -1981 |
| Leo III/55 (326) | NDPS (GPO) | Portsmouth | 1966 -1981 |
| Leo III/56 (360) | HM Dockyard | Chatham | 1967 -1977 |
| Leo III/58 (326) | NDPS (GPO) | Derby | 1966-1981 |
| Leo III/66 (326) | DNS (GPO), | Glasgow & Bristol) | 1969-1977 |
| Leo III/67 (326) | NDPS (GPO) | Derby | 1969 -1981 |
| Leo III/68 (326) | DNS (GPO), | Glasgow & Edinburgh | 1969 -1981 |
| Leo III/69 (326) | NDPS (GPO) | London | 1969 -1981 |
| Leo III/70 (326) | NDPS (GPO) | Bristol | 1969 -1981 |
| Leo III/90 (s) | NDPS (GPO) | London | 1964 -1965 |
| Leo III/93 (360) | VLD | Czechoslovakia | 1965-1979 |
| Leo III/94 (s) | London Boroughs Management Service Unit | London | 1967-1974 |
leo III installations
Note:
's': - Standard machine.
Store speed 13.5 μsec
'360': - 360 machine.
Store speed 6.0 μsec
'326': - 326 machine.
Store speed 2.6 μsec
