N8VEM VDU board

http://classiccmp.org/pipermail/cctalk/2009-October/277991.html N8VEM VDU board ROBO5.8 robo58 at optonline.net <mailto:cctalk%40classiccmp.org?Subject=Re%3A%20N8VEM%20VDU%20board&In-Reply -To=%3C004d01ca5053%24b64b0d40%2422e127c0%24%40net%3E> Sun Oct 18 19:33:00 CDT 2009 * Previous message: N8VEM <http://classiccmp.org/pipermail/cctalk/2009-October/277985.html> VDU board * Next message: CRT <http://classiccmp.org/pipermail/cctalk/2009-October/277986.html> Controllers Handbook by Gerry Kane * Messages sorted by: [ <http://classiccmp.org/pipermail/cctalk/2009-October/date.html#277991> date ] [ <http://classiccmp.org/pipermail/cctalk/2009-October/thread.html#277991> thread ] [ <http://classiccmp.org/pipermail/cctalk/2009-October/subject.html#277991> subject ] [ <http://classiccmp.org/pipermail/cctalk/2009-October/author.html#277991> author ] _____ Hi Andrew, Did you continue your work with the NEC uPD7220 GDC? If so can you tell us where you are with that project? Thanks Robo _____ size=2 width="100%" align=center> * Previous message: N8VEM <http://classiccmp.org/pipermail/cctalk/2009-October/277985.html> VDU board * Next message: CRT <http://classiccmp.org/pipermail/cctalk/2009-October/277986.html> Controllers Handbook by Gerry Kane * Messages sorted by: [ <http://classiccmp.org/pipermail/cctalk/2009-October/date.html#277991> date ] [ <http://classiccmp.org/pipermail/cctalk/2009-October/thread.html#277991> thread ] [ <http://classiccmp.org/pipermail/cctalk/2009-October/subject.html#277991> subject ] [ <http://classiccmp.org/pipermail/cctalk/2009-October/author.html#277991> author ] _____ More information about <http://www.classiccmp.org/mailman/listinfo/cctalk> the cctalk mailing list -----REPLY----- Hi Robo! Thanks! I am continuing work on the N8VEM S-100 projects. Currently I am working with some other people on S-100 related projects. I recently made a PCB manufacturing order for a group buy of N8VEM S-100 prototyping boards. With the larger quantity, I was able to reduce the cost per board to $18 down from $25 each originally. The next project is a joint project with another builder to make a different S-100 board (TBA) but not the uPD7220 board. I am still seeking basic information on the uPD7220 GDC and there is very little available. If you know where the uPD7220 User Manual and/or Design Guide are (paper or scanned), I would certainly appreciate some help in getting the information. I have the datasheet and some simple stuff gleaned from the web but that is insufficient information to design a full blown S-100 board from scratch. I am looking for some sample circuits to help with design and prototyping. Dan Roganti has (I think) a copy of the User Manual and is scanning it which should be available eventually. I can tell you with confidence after designing and prototyping the N8VEM VDU board, which was largely based on an already existing design, that video boards are complicated devices. Presently, I am working to build up the S-100 design skill set. Making S-100 boards is quite different than the ECB Eurocard designs I have done for the N8VEM project. Hopefully the third N8VEM S-100 board will be out soon and we can move on to more complex projects. I consider the uPD7220 design probably to be one of the more complicated designs so it will be a later project. I would like to do some simple boards like one each for parallel, serial, SRAM, RTC, etc. Maybe a debug board would be good depending on what is available. Eventually more complicated designs like a CPU board and/or graphics board. Given my skill set, available time, and tools the selection of projects is rather limited. Thanks and have a nice day! Andrew Lynch