Oracle 8i isn't supported on Windows 10. You needed 11.2.0.4 in order to run Oracle on Windows 8 - let alone Windows 10 I'll see if I can find the OS compatibility chart for you. Seriously, I don't think that it will happen any time soon because there are plenty of Mac work arounds even though I would love to have client.
Re: Oracle 8i Client For Mac Download
Have you tried running your XP software in a VM under windows 10? Oracle's VirtualBox or VMWare's virtual manager for PCs can be obtained for free. It would allow you both hardware and OS independence. In many cases functionality that was in older operating systems is no longer available. This also allows you to snapshot the virtual-computer for backups. I've found using GHOST by Symantec and creating a 'copy' of a system into a windows virtual disk (VHD) file works perfectly under Oracle's free VirtualBox (OVB). You can then run that image under OVB on mac, linux, windows perfectly (I'm currently doing it on several systems).
Oracle 8i Download
OpenLink Lite ODBC Driver for Oracle 8i & 9i provides transparent access to remote databases from any ODBC-compliant application. Desktop Productivity Tools (i.e., Spreadsheets, Word Processors, Presentation Packages, Desktop Databases, Personal Organizers, etc.), Client-Server Application Development Environments, Web-based Database Publishing Tools, and Computer Telephony Integration packages, are just a few of the many products that can take advantage of our standards compliance. Blistering Performance. ODBC v1.0 through v3.5 Compliance. ODBC Core, Level 1, Level 2, and Extensions support. Client-based Scrollable Cursor Support.