On 2/3/06, Richard <legalize at xmission.com> wrote: http://www.incolor.com/bill_r/elf/html/elf-1-33.htm I even used real HP displays (electrically identical to TIL-311s, but in a different package) and 1822 (5101) 256x4 SRAMs. If you are shooting for software compatibility without a slavish devotion to the 1976 appearance, you can use a modern 32Kx8 SRAM and even add a latch to access memory over 256 bytes (but toggling in that much data is kinda tedious). You will find it hard to locate a genuine 1861, but Spare Time Gizmos has a modern 1861 pin-compatible emulator (a shift register, a counter, and two 22V10 GALs) that fits in the socket for a real 1861. If you don't care about video, you can get a newer 1802 processor and run the entire thing at 5MHz. For those that don't know, there's a reasonably active 1802 group on Yahoo... http://groups.yahoo.com/group/cosmacelf/ ... I'd recommend it if you want to play with the 1802. -ethan