Dave Toxik wrote:
I was just leafing through my BATMAN IN THE 1980s collection and it mention that during thw early 1980s Batman and Detective were linked month to month.
A few questions:
1 - What issues did this run through?
2 - How long did this continue?
Although there were slight passages of continuity between the books during 1980, the books weren't strongly linked, with some stories being continued into the other book until 1981. At first there were various sub-plots that traveled from book to book (Vick Vale trying to prove Batman was Bruce Wayne, the Gotham mayoral election), but eventually stories began in Detective would continue or conclude in Batman.
From what I can tell, the Vicki Vale subpot first began in Detective 509.
which continued in Batman 343

And that's when things took off. With Gerry Conway as writer and Gene Colan and Don Newton as pencilers on Batman and Detective, respectively, until the pencilers switched books full-time with Batman 346 and Detective 528.
Conway continued as writer to Batman 359 and Detective 526 (Batman's 500th appearance). His run contained a lot of cross-continuity which tended to focus on Batman's rich stable of villains including the Riddler, Two-Face, the Mad Hatter, Hugo Strange, "Boss" Rupert Thorne, and Deadshot and introduced new villains Croc and the Squid. His run culminated with the introduction of Dick Grayson's replacement of Jason Todd as Robin.
Doug Moench then took on the writing chores with Batman 360 and Detective 527, continuing with the cross-continuity between books and continued using other Batman villains like the Joker, the Penguin, Mr. Freeze, Poison Ivy, Cat-Man, Scarecrow, as well as Two-Face, the Mad Hatter and introducing new villains, particularly Nocturna and the Night Thief.
Don Newton quit Batman, making 379 his last issue. (He died shortly thereafter.) Richard Howell took over as penciler for awhile and then he was replaced by Tom Mandrake. Unfortunately the magic of the series seemed to die when Newton left.
This continued until the extra-large Batman 400, which was Moench's last issue. Check out the artists on that one!

Colan left Detective with issue 545, and was replaced by Pat Broderick. Colan then returned with 553 and stayed on until 567 which was guest-written by Harlen Ellison, but this brought an end to the cross-continuity.
Dave Toxik wrote:
Is it worth checking out?
I loved the run as long as Newton and Colan were the artists. There are some great stories in that run and you can see where they were the inspiration for many of the episodes of Batman TAS.