In 3.9

100 printOn: Transcript base: 8 showRadix: false 100
100 printOn: Transcript base: 10 showRadix: false 100
100 printOn: Transcript base: 16 showRadix: false 100

> Actually #printOn:base:showRadix: will fail for any showRadix:  
> false unless base is 10. Sounds weird? Yeah. Here are examples:
>
>   100 printOn: Transcript base:  8 showRadix: false "->fails"
>   100 printOn: Transcript base: 10 showRadix: false "->succeeds"
>   100 printOn: Transcript base: 16 showRadix: false "->fails"
>
> Looks like #printStringRadix: is supposed to return a radix  
> whenever invoked but doesn't. Note how it is actually special- 
> casing radix 10 - it looks like it's expecting #printStringBase: to  
> add the "16r" prefix which apparently #printStringBase: doesn't (or  
> rather "no longer") do.
>
> BTW, this is a classic screw-up that tests would have found in no  
> time. Where are they when you need 'em?

Indeed.
Send them I will add them to 3.9 (else I will do it).