Viking QTO QBUS board (was Re: Viking QTO WBUS board)

David Barnes wrote Thanks. I also need to sort out an address decode PAL if I am to succeed in changing this QTO to a QDO or better yet a QDT card. I'm buzzing out the only other socketed chip on the board (a 16L8 PAL) that is doing the address decode from BBS7, BDAL12-BDAL2 then 4 inputs from jumpers & providing 1 output to select the Disk CSR/reg & Tape CSR/reg. How the one select provides for 4 word registers at discontiguous addresses I am still thinking about... Then I need to figure out how to blow PALs. Never had the pleasure of doing that bit of fun yet :) the two big 48pin devices in the middle of the board would appear to be dual port rams (1K x 8 each I think from reading the manuals on Zanes site) Fingers crossed I can get an EPROM image for it. greg