If you install over the previous version (base), you do not need the base CD for installation.
If want to install the ISR/QSR on a new directory, then you will need the base CD (IC5.0).
No.
EACH version [5.001, 5.033, etc] needs its Base.
To be more specific:
1. A 5.001 installation can not be upgraded by a 5.033 ISR/QSR
2. A 5.033, if already installed, just needs a 5.033 ISR/QSR [no need for 5.033 Base]. However, if not installed, a 5.033 will first need the 5.033 Base to be installed, and then updated with the latest 5.033 ISR or QSR.
If your company bought the C@dence's software, you would have upgrade servce.
They will give you a set of CD including Base. You'd better use this one, and download the most updated QSR/ISR.
Again - the Cadence rule for same version "X.YZ" is:
You just need latest QSR or ISR or UPDATE for exisiting installation to be updated !
You need Base & latest QSR or ISR or UPDATE for new installation to be updated !