Usebase and Collgen still use expanded memory (EMS) if it is available. EMS can greatly speed up some operations. Consult your DOS manual to find out how to access EMS. The rest of the programs now use Extended memory if it is available. Add the following line to your AUTOEXEC.BAT file,
where x is the amount of space you wish to make available for TACT. For example, 2048 would allocate up to 2MB of expanded memory when needed. The maximum that TACT can use is 4096 (4MB).
On rare occasions, this EMS support can cause Usebase or Collgen to crash. If this happens to you, set TACTEMS=0, to disable the use of EMS.