Todd, Its B-i0 to bi7 the S100 bus bit *input *lines. These are the *output* upper 8 bits (of 16) for S100 bus 16 bit transfers. The direction is pin 2-> to pin 18 etc. Only relevant on the mezzanine board for 16 bit transfers.
On Monday, July 27, 2015 at 12:54:42 PM UTC-7, Todd Miller wrote: > I have an early ver SMB. > > I has worked fine for years in my Imsai displaying address & instruction. > > Now that I have finished a mini ver of the Imsai, I want to use it there. > My problem is it will not display the instruction, i'ts always FF. > > Looking at the board layout and schematics, Til311 DIS7 and DIS8 are the > for the Data display.. > > What I don't understand is they are strapped to B-D10-D17, shouldn't > they be hooked to B-D0-D7. > > I look at it like this; > > The Hex displays are on the buffered Data bus, to enable display; pin 5 > of the Til311should be grounded. This is the same as latch_data_8*. > > I tried grounding U10 pin 6, latch_data_8* with no results. Is it > possible > one of the boards is asserting something to prevent a read from the bus ? > > Time for a break.... > > > Todd > -- 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.
