From: Jesus Calvino-F. <Je...@ec...> - 2003-03-14 03:17:25
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Hi Rod, The 74573 is connected correctly. Pins 2 to 9 go to the Address/Data bus (AD0 to AD7) of the 80535 (pins 52 to 59). Pin 11, the latch enable goes to pin 50 of the 80535 (ALE). Pin 11, the output enable, is grounded. Finally pins 12 to 19 go to the address bus (A00 to A15) that carry them to the 27256 and 62256. Also, do you think a design from 1995 (look at the title box) would still be around if it were incorrect? Best regards, Jesus At 03:18 PM 3/14/2003 +1300, Rod Boyce wrote: >It not connected to the correct address and data lines. It looks like it >is connected as a buffer of A8 to A15 what about A0 to A7 and D0 to D7? > >This latch is in teh wrong place and not connected correctly. A good idea >but you need to look in the net for more generic 8051 expanded memory >model digrams. > >This is my two cents worth I'm happy to be proven wrong but I do not >beleive this will work in is current setup. > >Regards, >Rod > >On Thu, 13 Mar 2003 10:44:57 -0800 >Jesus Calvino-Fraga <Je...@ec...> wrote: > > > The latch is a 74573 at coordinate B6. > > > > At 06:51 AM 3/14/03 +1300, you wrote: > > >You are missing the address decoder latch on the low order address > > >bytes. This will never work if teh processor is a bog standard 8051. > > > > > >Regards, > > >Rod > > > > > > > > >On Thu, 13 Mar 2003 10:13:02 +0100 > > >Peter Bozzay <alt...@go...> wrote: > > > > > > > > You just have to wire the chips correctly.... > > > > Yes, look at this: > > > > http://www1.uni-bremen.de/~g16i/gifs/sp485.gif > > > > > > > > Peter > > > > > > > > ########################################### > > > > Ezt a levelet az F-Secure Anti-Virus for Internet Mail ellen_rizte. > > > > Miskolci Egyetem Sz_m_t_k_zpont > > > > > > > > > > > > ------------------------------------------------------- > > > > This SF.net email is sponsored by:Crypto Challenge is now open! > > > > Get cracking and register here for some mind boggling fun and > > > > the chance of winning an Apple iPod: > > > > http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0031en > > > > _______________________________________________ > > > > Sdcc-user mailing list > > > > Sdc...@li... > > > > https://lists.sourceforge.net/lists/listinfo/sdcc-user > > > > > > > > > > > > >------------------------------------------------------- > > >This SF.net email is sponsored by:Crypto Challenge is now open! > > >Get cracking and register here for some mind boggling fun and > > >the chance of winning an Apple iPod: > > >http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0031en > > >_______________________________________________ > > >Sdcc-user mailing list > > >Sdc...@li... > > >https://lists.sourceforge.net/lists/listinfo/sdcc-user > > > > > > > > > > ------------------------------------------------------- > > This SF.net email is sponsored by:Crypto Challenge is now open! > > Get cracking and register here for some mind boggling fun and > > the chance of winning an Apple iPod: > > http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0031en > > _______________________________________________ > > Sdcc-user mailing list > > Sdc...@li... > > https://lists.sourceforge.net/lists/listinfo/sdcc-user > > |