Alpha Micro - AM-500 Hard Disk Controller
This board interfaced the one to four CDC 9427H (Hawk) hard
drives that came with the Alpha Micro systems.
The board contained a CPU module, a DMA controller and a 16X8 FIFO buffer,
1K of RAM and 2K of ROM. The max transfer rate was 2.5 MHZ. The sector
size was 512 bytes/sector. The S-100 Phantom line could be used with the
board. It went low during a bootstrap load. The CPU loads the
PROM at address 0F400H and moves it to 7C00H on the S-100 Bus. Its not
clear why but the manual never names the onboard CPU. It seems in every way
to be a Z80 with presumably a Zilog DMA controller.
The manual for this board can be obtained
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