DC1000 tapes work as well as the DC100A tapes in the HP85, HP9815A and HP9825A/B. I use them myself and have sold many of them previously; they are somewhat longer and therefore allow for somewhat more storage space. 8 boxes (5 tapes per box) of them on ebay now in a Dutch auction. I thought that I post a link to them here in case anyone needs some (this is quite a deal unless the price gets bid way up):
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5120222892&ssPageName=STRK:MEWA:IT
-Katie