I don't know if there's room, but you could use the output on port EFh for 8 LEDs for diagnostic progress.
Sent from my iPhone > On Nov 20, 2014, at 11:14 AM, John Monahan <[email protected]> wrote: > > Can we have the sense switch (IOBYTE) pegged to 0EFH to make life simple. Is > used a lot in our earlier software. > John > > > From: [email protected] [mailto:[email protected]] On > Behalf Of Richard Cini > Sent: Thursday, November 20, 2014 7:33 AM > To: [email protected] > Subject: Re: [N8VEM-S100:5635] Re: 8080a board > > All good ideas, especially the 8085 and the sense switch input. I wish the > msdos board had a sense switch input. > > Sent from my iPhone > > On Nov 20, 2014, at 10:09 AM, Tom Lafleur <[email protected]> wrote: > > Some notes for Ver one... To gain some room on the board.... > > As suggested before.... > > Use only 4 wire rs232 with max232a/tr202, removing need for +-12v ( 3 to 4 > chip saving) > Move to 8085, no need for +12 or -5v, less support chip needed... ( ~2 chip > saving) > > Make board stand alone, no other boards needed to make it run... ( plus 1 > chip) > Fix upper address and data lines to bus issues . (Plus 2 chips) > > New ideas... > > Replace 8212's with 74als logic (~ 3 chip saving) > > Replace ram chips with one larger chip, (wasting part of the chip to save > room if needed) 64k x 8 or larger like an as6c4008 with a poor man's mmu if > their room on board...(use output port?) like zeta board.... (~ plus 1 to 2 > chip saving) > > If room, allow room for a dip switch with pull-ups on input port.... (~ plus > 1 chip) > > > Just my ideas from building the board.... > > > > > > i~~ _/) ~~~~ _/) ~~~~ _/) ~~~~ _/) ~~i > > Tom Lafleur > > > On Nov 19, 2014, at 8:00 PM, Crusty OMO <[email protected]> wrote: > > Opps, thanks for letting me know... I guess it's a cut n paste error or just > an over sight. > > > Date: Wed, 19 Nov 2014 16:34:41 -0800 > Subject: 8080a board > From: [email protected] > To: [email protected] > > fyi... > > > It appears that UART1 at A5 is connected to COM1 port, P1/P2 on the board, > but the schematic say its connected to P3/P4 > > -- > > ~~ _/) ~~~~ _/) ~~~~ _/) ~~~~ _/) ~~ > > Tom Lafleur > > -- > You received this message because you are subscribed to the Google Groups > "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- > You received this message because you are subscribed to the Google Groups > "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- > You received this message because you are subscribed to the Google Groups > "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
