View Full Version : Long shot NEC APC PC98 Bus to ISA bus converter

October 1st, 2017, 03:53 PM
Just a quick request for your thoughts - having got a working DOS 2.11 boot disk and on noticing all the hard drive partitioning/formatting tools, the inevitable desire for hard drive capabilities has set in. I have worked out that this machine uses an early PC98 expansion bus which is different to the ISA standard. Getting the official hard drive controller card and drive is going to be next to impossible so what about a PC98 to ISA bus adapter??

I spotted this on eBay:

http://www.ebay.co.uk/itm/VINTAGE-NEC-PowerMate-SX-Plus-NEC-16T-G8EEZ-136-456059-C-03-ISA-RAISER-CARD-/222081372007?hash=item33b514cf67:g:eh4AAOSwbwlXCgd c

From what I have just read about the NEC Powermate SX Plus, it was fully ISA compatible. but is that because it had ISA slots on the motherboard OR, as this card suggests - it had one PC98 slot on the motherboard and an adapter with built in logic to convert to ISA bus logic?

Would plugging it in to my NEC APC and then plugging in an ISA MFM hard drive controller suddenly give me hard drive abilities or am I being childishly naive? I nearly asked the sellers advice but looking at his other items for sale, I imagine he may be clueless.


Just a shot in the desperate dark?

Thanks for any thoughts!

October 1st, 2017, 04:23 PM
PC-98 uses the C-Bus. Later ones had PCI slots. That ISA riser card will not work on your system. C-Bus cards have a smaller edge connector. The best you can do is troll the JP auctions and see if a hdd controller and harddrive show up.

Pop on over to #vc @ irc.slashnet.org and techfury should be able to give you some advice re PC-98s


October 1st, 2017, 05:49 PM
C-bus is 100 pins. Here's the callout (https://ja.wikipedia.org/wiki/C%E3%83%90%E3%82%B9).

But PC98 is very, very different. Here are some of the differences (http://euc.jp/articles/pc9800.en.html).

October 2nd, 2017, 12:12 AM
C-bus is 100 pins. Here's the callout (https://ja.wikipedia.org/wiki/C%E3%83%90%E3%82%B9).

But PC98 is very, very different. Here are some of the differences (http://euc.jp/articles/pc9800.en.html).

Thanks for those links, defiantly not come across them so far and the second one especially is a great historical reference.

OK, that ends that thought then :)

October 2nd, 2017, 06:54 AM
The NEC PowerMates were standard IBM PC clones, not PC98 machines.