computer that spell it). have misplaced was willing to boot disks or at particular beast. The part is a Hitachi 64180, an improved Z80. Zilog also makes a similar part, the Z180. I recall the article, It was from Ciarcia's Circuit Cellar series. I think his company sold the kits, MicroMint (?). The 64180 was a nice improvement, made it much easier to add DRAM to a Z80. The drawbacks were the odd pin spacing on the DIP (70 mil centers instead of 100) and a less than perfect fit to the newer Zilog peripherals like the SCC or CIO. I believe the Zilog version fixed up the signal problems with cascading interrupts and also added one more address line (to a full 1MB). Aside from the faster clock rates and built-in peripherals, the nicest feature of the '180s was the memory management. The CPU had an integrated memory management unit to extend the 64K address of a regular Z80 out to either 512K or 1M, using three bank-switched regions. I still have a homemade CP/M system using the 64180, 256K DRAM, 16KB EPROM, two CIOs, one SCC, a National 58167 clock calendar, and a WD MFM hard/floppy controller card. It runs CP/M V3 and used the MMU to access all of the 256K RAM. I built it before Ciarcia came out with his board, chances are I would have used his for the project instead of doing a custom card. I keep it running for sentimental value, it was the first card I ever designed (and got working) with dynamic RAMs. Jack Peacock