Date: Wed, 17 Jun 2009 21:37:04 -0400 From: Andrew Lynch <lynchaj at yahoo.com> Reply-To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> To: cctalk at classiccmp.org Subject: RE:NEC uPD7220/GDC Design Manual --- On Wed, 6/10/09, Andrew Lynch wrote: interested in selling it? I contacted NEC and they didn't know anything about it. Apparently very few people still have the manual and bitsavers doesn't have it either. I did some library searches but no luck although it is cited as a reference in a couple of college papers like masters thesis, etc. What I really need to know is if I can implement a simple circuit using few enough 74LS TTL ICs to fit on a Eurocard ECB board. That means it can't be more than about 30 maximum. Using high capacity SRAMs should help but I think it requires some funky latching mechanisms to share the video address and data lines. I looked at the NEC APC video board and it is just huge. I hope that is not an indication of the complexity needed! Thanks and have a nice day! Andrew Lynch

From: lynchaj at yahoo.com To: cctalk at classiccmp.org Subject: RE:NEC uPD7220/GDC Design Manual Date: Wed, 17 Jun 2009 21:37:04 -0400 --- On Wed, 6/10/09, Andrew Lynch wrote: I waited with a response, assuming that somebody has the manual you are looking for. I am not 100% sure, but I might have that manual. I am sure that I do have _a_ NEC 7220 GDC manual, and I remember (15+ years ago) that I used that manual to write a BASIC program to calculate register values based on the timing parameters for the VDU. I don't remember if the manual contained hardware info, it might. Next time I am in the old house, I will search for the manual in the attic. Perhaps this weekend ... - Henk. -----REPLY----- Hi Henk! Thanks! Any help you can provide is greatly appreciated. I am interested and researching the possibility of a NEC uPD7220 home brew video board. The SY6545 video board I made for the N8VEM project is working out really well but it is just a simple character only display. Ideally, you could scan the book if that is possible but if not would you be interested in selling it? I contacted NEC and they didn't know anything about it. Apparently very few people still have the manual and bitsavers doesn't have it either. I did some library searches but no luck although it is cited as a reference in a couple of college papers like masters thesis, etc. What I really need to know is if I can implement a simple circuit using few enough 74LS TTL ICs to fit on a Eurocard ECB board. That means it can't be more than about 30 maximum. Using high capacity SRAMs should help but I think it requires some funky latching mechanisms to share the video address and data lines. I looked at the NEC APC video board and it is just huge. I hope that is not an indication of the complexity needed! Thanks and have a nice day! Andrew Lynch