If you look at photo DSC_0029 you can see the serial number and the model number M0001D (which is the EDU 512ke). The 512ke was introduced in April 1986 and came with a 800K floppy drive standard (according to Mactracker) and was discontinued in Sept. 1987. The Plus was introduced in Jan. 1986 so there was an almost a 1.5 year overlap hence the 800K drives in the 512ke

Click to expand...

If my 512Ke (detailed in Mac128's database) is worth anything as a yardstick, and it was first owned by the U of Western Australia under an Apple/Universities consortium arrangement, the 512Ke was always M0001E (extended), acquiring the extra D for education purposes only when sold into that environment. The full keyboard originally supplied (demonstrated by its dated, non-factory label) was part of the deliberate conception of the 512Ke as the 'Mac Minus' (its Apple code-name) low-end partner to the high-end Mac Plus.

If that thinking about suffixes was consistently applied by Apple, somewhere, at some time, a 512K may turn up bearing M0001WD.

de