Q: how to put system 6 on a floppy

You might find a solution at this link.

http://oldermac.hardsdisk.net/oldmac.html#hard

You will need an intermediate Mac capable of running a Classic Self-Extracting Archive from Apple's download site, and then you'll need a USB floppy drive for your Macbook to write it out:

http://www.info.apple.com/support/oldersoftwarelist.html

Macintosh/System/Older_System/System_6.0.x/SSW_6.0.8-1.4MB_Disk1of2.sea.bin
Macintosh/System/Older_System/System_6.0.x/SSW_6.0.8-1.4MB_Disk2of2.sea.bin

If you don't want to go through this yourself, system disks are offered for sale here (not my site):

http://rescuemyclassicmac.com/buyadisk/buyadisk.html

The article below contains information about how to create 1.44 MB Mac boot floppies under Mac OS X. Without having tested this procedure at all, I cannot say whether recent system versions would work or not.

http://lowendmac.com/brierley/08pb/classic-mac-boot-floppy.html

Otherwise, the easiest way would probably be to locate another older (pre-1998) Mac with a built-in floppy drive for 1.44 MB (and possibly with a direct Internet connection). JustSomeGuy provided you with links to two 6.0.8 (1.44 MB) downloads. A utility called StuffIt Expander can be used to decode downloaded MacBinary (.bin) files on the Mac in question. After decoding and decompression, one can create  sector-copied floppies from the resulting disk images via (the Make A Copy button in) Disk Copy 4.2.

http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Disk_Copy/

If it is absolutely impossible to locate another older Mac, one could even use a Windows PC with a floppy drive (an appropriate version of Aladdin/StuffIt Expander for Windows, and a disk-image utility like WinImage, would be needed in order to make sector-copied 1.44 MB floppies).

Jan

Is your SE a FDHD/Superdrive model? If not, you are going to need another Mac with a built-in floppy drive to make 800k boot disks, as standard USB floppy drives/PC floppy drives do not have the capability of writing 800k images.