VBRANDT@DBNUAMA1.BITNET (12/19/88)
Ignac Kolenko <electro!electro!ignac@ucbvax.Berkeley.EDU> asks: > i have a question regarding the exact function of the upper data/lower >data strobes on the m68k. can the LDS be used in place of the missing A0 line? Yes, that works. >also, if the above is correct, can i do the following: > >MOVEA.L $FB0000,A0 >TST.B (A0,D0.W) Sure. > case anyone is wonderin' why i'm asking, i want to try to build an interface >to my atari 1040st cartridge port, which doesn't have write access capability. >i therefore have to use the bottom 8 lines of the address bus as a "data bus" >when i want to write to the cartridge port address space, and using one of the >higher address lines a pseudo read/write line. (...) This is exactly the way all those cartrige port boards sold commercially and offered in magazine projects do the trick. People have used this kind of I/O interface for all kinds of stuff, from con- trolling a robot arm to hooking up a PC-style hard disk. If you want to hear more, you should subscribe to the Info-Atari16 digest (send a message to Info-Atari16-Request@Score.Stanford.EDU including your path from there). Bitnet: VBRANDT@DBNUAMA1 Volker A. Brandt UUCP: ...!unido!DBNUAMA1.bitnet!vbrandt Angewandte Mathematik ARPAnet: VBRANDT%DBNUAMA1.BITNET@CUNYVM.CUNY.EDU (Bonn, West Germany)