goldfarb (07/08/82)
I have an H-8 with 128K of memory, a Z80A, an S-100 disk controller, and some other goodies. It runs CP/M on normal, 8" floppies (Shugart 851's). D-G Electronic Developments Co., 1827 S. Armstrong St., Garland, TX. 75020, supplied the CPU, replacement front-panel EPROM, and the dynamic RAM. Their prices were quite reasonable, as were their designs, enabling the old H-8 to use the Z80A and all 64K of address space at 4Mhz. The disk controller is an S-100 type, a Jade Double D purchased from Jade Computer Products in California for $60 for the bare board. It has an on-board Z80A and uses a WD 179X FDC chip. I made an adapter card to create an S-100 bus slot for the H-8. This required only two bus buffers and five other IC's, plus a slight mod to the memory cards to handle the S-100 PHANTOM* signal. Since the Jade controller does not use DMA, no fancy interfacing was necessary. With the above configuration plus a Heath 4-port serial card, the old H-8 is a reasonable CP/M machine. But don't count on Heath (or anyone else's) support for too long: the H-8 is dead! Ben Goldfarb USENET: ...!duke!ucf-cs!goldfarb ARPANET: Goldfarb.ucf-cs @ UDel-Relay