[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [N8VEM-S100:1460] Re: S-100 board reorders

Where were you guys when we started this 68K board. In retrospect we probably should have! The board started out as a direct copy of the Wilcox book board. That board was a bus master (only).  The next step was to convert it to a master/slave combination thereby adding to its utility.   This actually involved a lot of modifications and additions.


I think if we were going to do anything we would next go to a 68020 or 30 much as we are doing with the 8086/80286 to 80386.  However I can tell you going to true 32 bits  with >16M memory access  at > 20MHz clock speeds is not as easy as it sounds.


Hopeful Andrew’s tracer will arrive home soon.  The board will allow decent development work to get started. Remember the 68010 is a direct plugin.    Personally I am worried all the traces come our right -- it’s been a long time in the oven.   I hope people appreciate there is always risk with these boards coming up duds!






John Monahan Ph.D

e-mail: mon...@vitasoft.org

Text:    mon...@txt.att.net



From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of yoda
Sent: Sunday, February 24, 2013 12:43 PM
To: n8vem...@googlegroups.com
Subject: [N8VEM-S100:1460] Re: S-100 board reorders


As another thought - why not substitute a 68 pin PLCC version of the 68K (MC68000FN12) and an AT29C1024 16 bit 44pin PLCC for the eeprom.   These would drastically reduce the density on the board an might make the trace routing simpler.  The 16 bit eeprom would make the programming simpler as well - just a thought.  I have both in hand so it would not be a problem and they are reasonably priced as well.



On Sunday, February 24, 2013 2:32:18 PM UTC-6, yoda wrote:

How close are we on the S-100 68K???  There is a lot of pent up demand for that board - especially me as I work on the other 68xxx system - I am trying to write platform independent code and would like to test it on the new 68K board as well.





On Sunday, February 24, 2013 11:17:26 AM UTC-6, lynchaj wrote:


Well I was hoping to get the S-100 68K and S-100 80286 CPU board PCBs ordered next but they are not cooperating.  The S-100 68K CPU board is nearly complete and should be done soon.  It has taken much longer than I expected though.  I would like it to complete trace route optimization before ordering PCBs.

In the meantime, I am thinking we could make another round of S-100 board reorders.  What I am thinking is the S-100 IDE V2 PCBs are always popular and so are the S-100 buffered prototyping board PCBs.  I would like to do another round of those and hopefully while they are settling the S-100 68K CPU and the S-100 80286 CPU boards will complete or at least get “close enough”


Another idea is the S-100 bus terminator board.  Basically there are 10 builders willing to get these boards “as is” which is the full sized PCB with some prototyping area.  Nothing fancy but useful for terminating a legacy S-100 backplane.  However these have *NOT* been prototyped so there is some additional risk.  I think it is minor though since the S-100 backplane has this exact circuit and it works fine.


Ideas?  Thoughts?  Comments?  Questions?  All welcome!  Please lets discuss what the next steps should be.  Thanks and have a nice day!

Andrew Lynch

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 n8vem-s100+...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.