I'm sorry, but I have to share these awesome podcasts. The first you've heard of and hear spots from during the Retro Mac Cast -
Earl Evans' - Retrobits Podcast
This podcast covers older systems - generally before the IBM PC but slips occasionally and covers both history, details and what Earl likes to call "Modern Day Fun". What you can do with them now or what things you can do to experience these old machines. His latest episode covers the Commodore PET 2001 series. Good stuff and full of Retro Goodness (tm).
The second podcast is a newer one but from the first time you listen to it, you know it's something different. There are only two episodes so far but Robert Ashley
(twitter link) has created an incredible podcast drawing inspiration from NPR style editing and music but covering gaming, gaming history, and the people involved. This man is an artist. This podcast is genius and proof that art can be found anywhere there is enough passion.
Robert Ashley's - A Life Well Wasted
Go listen now. I mean it.