Qbus identification

On 4 April 2013 16:15, Pete Turnbull <pete at dunnington.plus.com> wrote: That's not correct. The H9273-A backplane (quad wide, nine slot long, QQ/CD 18-bit) of the BA11-N box can be replaced with an H9275-A backplane (quad wide, nine slot long, QQ/QQ 22-bit) which is a serpentine backplane specifically designed to be put inside of a BA11-N box (for OEM use). I should know; I have an H9275-A backplane! (I don't have a BA11-N box to use it in though...) The H9276-A backplane of the BA11-S is a 22-bit wide QQ/CD straight backplane though. The "odd" DDV11 backplane is also a 9 slot backplane, but it is 18-bit, has the AB/CD slots as standard serpentine QBUS and the EF slots as just power and grounds. (For shits and giggles, rewire them as CD slots and have a QQ/QQ/CD backplane.) Also of note, the BA11-M box with H9720 is an 18-bit quad-wide serpentine backplane of four slots length; which can also have an H9270-Q backplane installed which is the same size but 22-bit. The BA11-V is always 18-bit (don't know if you can easily upgrade it to 22-bit) but only dual wide and four slots long if I remember (so, the serpentine moniker is incorrect). Only other QBUS backplanes of note are the H9281 series, where again the serpentine/straight+CD distinction is a non-issue since those are all dual-wide backplanes of various lengths. (And there's the H9278 of the BA23 which we'll ignore as you probably won't see one of those floating around "naked" without its box.) Cheers, Christian