Cromemco WDI-II The Cromemco WDI-II was what the
WDI should have been. While still not ST-506
compatible it did allow you to interface 5" or 8" hard disks. It was used with their
HDD-22, HD-11 and HD5 drives. It still was quite specific to Cromemco hardware
however.
The controller could work with up to 6
separate drives and utilized DMA memory access for fast data transfers. The
software supplied was fairly complex and set to work with their Cromix
Multi-user system. However they did also supply a stripped down CDOS (~CPM)
version as well. If you are going to use this board start with their HDIAG
diagnostic program. BTW, a fast 4MHz CPU was required. A 2 MHz Z80 could not
keep up with the data. The board had interrupt capability but was not used
by their software. There was elaborate circuitry to handle S-100 systems
that had multiple DMA controllers on the bus. Again some 15 IO ports were
eaten up to run the board. The default port with their software was E0H to EFH.
