The PowerPC ThinkPad series, (800, 820, 821, 822, 823, 850, 851, 860) were unique in that they ran on the PowerPC architecture, and not the x86 architecture. They all used the IBM PowerPC 603e CPU. The 800 may have used a 603, and it is unclear if the 800 was experimental or not. All units used SCSI 2 instead of IDE. The units are believed to have all been extremely expensive, as the 850 cost upwards of $12,000 USD. The 800 series can run Windows NT 3.5 (probably 4.0 as well), OS/2, AIX 4.14, Solaris Desktop 2.5.1 PowerPC Edition and Linux.