Ian I had a NorthStar Horizon years ago (wish I had not let it go!). It used, I think either 3 or 4 Dynabyte 16K DRAM boards, but don't remember which part number. I remember buying the Dynabyte boards as soon as they came on the market, so may have been early model. I had no problem at all with them. My system had a 5Meg HD and a 5-1/4 floppy. System worked beautifully with CPM 2.2 as OS, and a Lear Seigler ADM-3a terminal. I recall having to patch the BIOS using something like DDT so it would work with different I/O cards! I think I used a Z80 cpu- don't know if it was somehow supplying refresh to memory, or if I let memory do its own refresh. Good Luck Leonard From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Ian McLaughlin Hello all, Sorry if this is a bit off topic. I have a Northstar Horizon that I am restoring. It came without any RAM boards. I acquired a Dynabyte 64k dynamic RAM board 800589-G, and I've been trying to get it to work with the Horizon. I've figured out the bank switching, and I'm able to switch banks in and out, but any writes to memory end up writing FF no matter what I write. It's been impossible to find any data on this board like schematics. I don't even know if it's compatible with the Horizon. Anyway, I'm wondering if anyone has a memory board (any size) that is compatible with the Northstar Horizon that they'd be willing to let go for a reasonable cost and willing to ship to Canada. Thanks in advance. Ian -- |