Yep, no more than 10 at once, and then you can get corruption. M$ Access (MDB) is not intended for multiple users. Similar to DBase / Foxpro DBF files or Paradox DB files.
For more than 10 users you need a client-server DBMS like M$ SQL Server, Interbase, Oracle, IBM DB2, etc. Or one of the Open Source ones: MySQL, FireBird, PosGre, etc. I just use MySQL because it's free
& easy to install & use ... it's also the DB most used for web applications such as Google's search engine ... so multiple users is not a problem
. It doesn't have all the advanced features like the commercial ones, but if you want those FireBird / PosGre is very close, if not better than some of the commercial DB's.
You could go for M$'s free SQL Express, but again that has limited user concurency. And you need a windows server to run it on for more than 10 users
. The Open Source stuff can run on anything, win desktop, server, linux, mac, you name it
.
You install the DBMS on a server (or designated desktop). Then you need that DB's ODBC driver (installed on all the client machines) and the ADOLisp library to link from lisp through ODBC to the server.
But this is getting a bit off topic, and I think a full fledged DBMS is a bit much unless you want to integrate several stuff into the same thing & get the info from a central source.