Thanks Neil, that was a neat design. In the end I have settled for the following “upgrade” of our SMB V2->V3.
New additions:- Continuous bus clock (Phi) display using an Intersil ICM2718D IC frequency display chip and 3 common cathode displays at top of the board. Continuous display in a LED bar of one (any) port that the CPU may be outputting to (e.g. console out). Trap the S100 bus Error signal (pin 98), forcing the current CPU into a wait state, displaying the address etc. Cleaned up TMA0-3 switching circuit (GAL based circuit) for faster response (and any designated port). The 4 TMA LED’s now display the current bus status. Place a 6X2 0.1” set of jumpers at top of board to display the (buffered) main S100 bus lines with a multiport logic probe (USBee, Saleae etc.) Some tweaks on old circuits including a broad Vcc line to the external HEX display pins. The problem I’m currently having is the freerouter is having a problem finding a layout solution. Am trying a few more rearrangements of the furniture. John From: [email protected] [mailto:[email protected]] On Behalf Of nbreeden Sent: Sunday, February 22, 2015 8:31 AM To: [email protected] Subject: [N8VEM-S100:6406] Re: A V3 version of our S100 bus System Monitor Board John, The N8VEM side of the house did a DSKY several years ago; I have one on one of my early N8VEM Z-80 builds; IMO it turned out really well. It used commonly stocked parts. If you decide to add an option for a DSKY type interface it might be a good starting point. http://n8vem-sbc.pbworks.com/f/DSKY+for+the+N8VEM+sbc.pdf -Neil -- 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.
