6.4) What "vaporware" computers/peripherals were never released?

Subject: 6.4) What "vaporware" computers/peripherals were never released?

Atari was a HUGE company, dominating Silicon Valley, and included a massive
research and development department which famously designed many, many
products that never saw the light of day. Here is a brief listing of many
Atari hardware model designations known to have existed internally to the
company, but which were never sold and are extremely rare (if they ever
existed at all). For definitive information on unreleased Atari products,
see:

Atari Historical Society, http://www.atari-history.com/ (Curt Vendel)

Atari 8-bit vaporware computers: (note some are more vaporous than others)
800D (Developers Bus System)
1000 Sweet 16 Project, lower end model. Became the 1200XL
1000-X Sweet 16 Project, higher end model. Became the 1200XL
1200 1200XL internally, many slight cosmetic differences
1200XLS 1200XL Show prototype, top-mounted cartridge slot
600 early 600XL, all black case, joyports on the left, missing PBI
800XL brown prototype
800XLD low-cost 1450XLD,no modem&speech,incl disk drive controller&FREDDIE
800XLCR Cost Reduced, with CGIA chip ("Keri"), which is a combined GTIA&ANTIC
900XLF early name for 65XE
1250XLD Earlier name for the 1450XLD
1400XL brown prototype
1400XL 800XL plus modem, speech synth.(looks like a 1200XL)
1450XL 1400XL plus room for 2 internal 5.25" drives(controller not included)
1450XLD 1400XL plus 5.25" floppy drive (Epson SD521 360K disk drives)
1600XL Amiga/Amiga-like.Now appears that 1850XLD was the model name for this
1650XLD to use 1450XLD case and 1200XL keyboard
1850XLD "Mickey" Atari clone of the Amiga Lorraine
65XEP 65XE plus 3.5" floppy drive, 5" green monitor
65XEM 65XE plus AMY sound chip

Atari 8-bit vaporware peripherals: (note some are more vaporous than others)
1027 PLUS -daisy-wheel, 80 columns
1053 -looks like a 1050, but supports DS/DD 360K format
1055 -a 1050 (SS/ED) with a 3.5" mechanism
1060 CP/M Add-On Module -"SweetPea" Z-80 CPU, 64K RAM, CP/M 2.2, 80col display
1090 XL Expansion System-5 PBI slots, CP/M/MS-DOS/Apple II compatible
XM128 -12" green monitor w/ built-in 80-column card
XC1411 -composite 14" color monitor (Goldstar)
XF521 -5.25" floppy drive - 1050 compatible, in XE style
XF351 -a 3.5" drive.
XC35 -an XF551 with a 3.5" mechanism
XTM201 -non-impact printer
XTC201 -XE Thermal Color Printer