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FW: S-100 Utility board KiCAD files uploaded to wiki


I’ll forward to the group and see if anyone wants to adopt this project.


The attached ZIP file is on the wiki in the S-100 Utility folder



Andrew Lynch


From: Neil Breeden [mailto:nbre...@me.com]
Sent: Sunday, October 12, 2014 12:06 PM
To: Andrew Lynch
Cc: 'Todd Goodman'; mon...@vitasoft.org
Subject: Re: S-100 Utility board KiCAD files uploaded to wiki




  I've been able to verify the following work:

   - Port decoding for the UART

   - The UART

   - The 27C256 EPROM
   - The 32K RAM at U27

   -  I can toggle bits on the Printer port


   I have a version of my BASIC in ROM that works on the board using the on-board EPROM, RAM and UART for console I/O.


  Other functions such as the RTC, Extra RAM (U29 and U18) and MSX ports have not been verified.


  Issues with the board (Version 01)

   - MREQ Issue (see attached) - Need to replace NAND with NOR gates

   - I'm not convinced that the RESET circuit works reliability 

Neil Breeden

On Oct 12, 2014, at 06:23 AM, Andrew Lynch <LYN...@YAHOO.COM> wrote:

Hi Todd


I uploaded the S-100 Utility board KiCAD files.  It occurred to me this morning they had not been uploaded previously.




Neil had debugged the board and it was probably nearly complete. 


It is probably close enough for a small batch of PCBs to hammer out the remaining issues.


The S-100 Utility board along with an S-100 VDP and S-100 Z80 CPU board form a three board core full hardware MSX2 compatible system.


Good luck!  Thanks and have a nice day!

Andrew Lynch