Coleco's ADAM SmartBASIC and the ADAM Home Software Library, both on cassette. Found them when sorting my cassette collection.
Found three 8" floppy disks (similar to the 5.25", but bigger).
Also found a PSION Organiser II, Model CM, complete with manual and a module with Concise Oxford Spelling dictionary.
Came across an old invoice from 12 April 1989 for an old PC:
Motherboard with Intel 80386 20MHz, overclocked to 25MHz, 2 MB RAM, SFr. 4'520.-
Floppy drive 5.25", SFr. 320.-
Full towercase with 220W powersupply, SFr. 570.-
Totalling: SFr 5'410.00
Discount 15%: SFr 811.50
Endprice: Swiss Francs 4'598.50 (= US$ 3'709.- / €2'939.- / £2'032.-)
[me weeps]