The first computer at PDI was a DEC PDP 11/44 with 128 kilobytes of memory. This was a lot of memory given that the computer had only 64 kilobytes (16-bits) of address space. It had a 20 megabyte disk. Attached to this was a $65,000 framebuffer which has a resolution of 512x512 and was 32 bits deep. The PDP-11 was soon replaced by a DEC VAX-11/780 and later PDI shifted to another superminicomputer called the Ridge32. This machine was 2-4 times faster than the VAX-11/780 at a fraction of the cost.