+Yurkie Posted March 28, 2011 Share Posted March 28, 2011 I finally got around to trying the +5Volt only DRAM mod that Raymond Jett originated. The original 4116 DRAM requires +5V, -5V and 12V to operate. This is a rather time consuming mod to perform, but I think that reliability makes it well worthwhile. The pictures below are of my friend cmart604's ColecoVision with the 4164 DRAM installed. I took pictures of the top and bottom of the board so that you can see the ICs and the solder joints. I don't know if there is much interest in this mod, but I will offer it as a service for $65. Quote Link to comment Share on other sites More sharing options...
+cmart604 Posted March 29, 2011 Share Posted March 29, 2011 Cooool. My CV is so pimped out. Quote Link to comment Share on other sites More sharing options...
SlowCoder Posted March 30, 2011 Share Posted March 30, 2011 Am I correct that this mod would allow the use of a modded power supply that doesn't have -5v? Other than that, what are the benefits? Quote Link to comment Share on other sites More sharing options...
+Yurkie Posted March 30, 2011 Author Share Posted March 30, 2011 Am I correct that this mod would allow the use of a modded power supply that doesn't have -5v? Other than that, what are the benefits? Beside the fact that the system is almost 30 years old and the +5V and 12V are suppose to be applied at the same time, you are benefiting from the fact that your no longer counting on 7 ceramic capacitors that where used for the -5V, 1 electrolytic capacitor and 2 inductors. 9 less components to go bad and cause failure. There may be more this was what I came up with when looking over the board. Quote Link to comment Share on other sites More sharing options...
+Yurkie Posted March 30, 2011 Author Share Posted March 30, 2011 Am I correct that this mod would allow the use of a modded power supply that doesn't have -5v? Other than that, what are the benefits? Beside the fact that the system is almost 30 years old and the +5V and 12V are suppose to be applied at the same time, you are benefiting from the fact that your no longer counting on 7 ceramic capacitors that where used for the -5V, 1 electrolytic capacitor and 2 inductors. 9 less components to go bad and cause failure. There may be more, this was what I came up with when looking over the board. EDiT :You still need the -5V for the controller ports. Quote Link to comment Share on other sites More sharing options...
+Yurkie Posted March 30, 2011 Author Share Posted March 30, 2011 EDiT :You still need the -5V for the controller ports. I just disconnected the -5V and the system works and the controllers worked on the controller test rom. The Super Action Controller test rom I have is corrupt, so I was not able to check a set of SACs. Perhaps the -5V is not needed for the controller ports. Quote Link to comment Share on other sites More sharing options...
atariappleman Posted May 31, 2011 Share Posted May 31, 2011 Based on Yurkie's outstanding workmanship in modifications to my ColecoVision in the past, I decided to invest in this DRAM replacement for peace of mind and overall operating efficiency. The modification and overall business transaction went flawlessly and I am very pleased with the finished product. I would recommend this modification to anyone that has significant time or money invested in their hardware. Thanks again for your continued support to the ColecoVision community. Quote Link to comment Share on other sites More sharing options...
+Yurkie Posted June 10, 2011 Author Share Posted June 10, 2011 (edited) Due to very low interest in this mod, I am no longer going to offer it as a mod service. To put some of the 4164 DRAM I have to use, I have decided to make up 2 complete ColecoVision systems that will have every mod and offer them for sale.... $200 + shipping It would cost $194 if you sent me a ColecoVision and had your system refurbished and modded with all this, so your basically getting the Hardware for free. These will ship Priority Mail and Insurance and Delivery Confirmation is required. These will be console and controllers that have been completely dissembled and throughly cleaned. When everything is reassembled I am going to wipe them down with Armour All and then dry wipe them to remove any access. This gives everything a like new appearance without being greasy. Controllers refurbished and working like brand new, with ball knobs and straightened cords on the controllers. Console completely refurbished and working perfect and with: Single Jack A/V composite mod Intro skip BIOS Pause button Mod 4164 socketed DRAM...replacing the original 4116s A perfect tested working power supply and the A/V cord. I will be working on these today and over the weekend. Pictures will be posted when these units are ready. If you are serious about buying one of these units you can send a PM. Upon completion I will post pictures and ask for payment. These will be 2 of the best cosmetic condition systems I have ever offered, and will work flawlessly. These systems will likely be nicer overall than the 2 system I keep for myself for gaming. Edited June 10, 2011 by Yurkie Quote Link to comment Share on other sites More sharing options...
ColecoDan Posted June 10, 2011 Share Posted June 10, 2011 pm'd Yurkie right away to steal one of these beauties. Quote Link to comment Share on other sites More sharing options...
+Yurkie Posted June 10, 2011 Author Share Posted June 10, 2011 pm'd Yurkie right away to steal one of these beauties. Thanks ColecoDan. You will getting one of the 2. Your a great gentleman to do business with and I appreciate your support. Quote Link to comment Share on other sites More sharing options...
Murph74 Posted June 10, 2011 Share Posted June 10, 2011 Any chance of a power supply mod to accompany? I'm interested, especially if the -5 is no longer required. Quote Link to comment Share on other sites More sharing options...
+Yurkie Posted June 10, 2011 Author Share Posted June 10, 2011 Any chance of a power supply mod to accompany? I'm interested, especially if the -5 is no longer required. Absolutely not. The offer is as stated. I was going over my inventory and I have 40 X 4164 DRAM ...8 of these 40 is for a friends ColecoVision, leaving me with enough to do 4 units. I may offer another complete system after I get these 2 done, since the first is ColecoDan's and you seem to want the other. Anybody that's interested feel free to send me a PM. Quote Link to comment Share on other sites More sharing options...
Bruce Tomlin Posted June 11, 2011 Share Posted June 11, 2011 (edited) EDiT :You still need the -5V for the controller ports. I checked the schematic, and it looks like the controller ports are using this to reverse-bias the diodes in the controllers or something like that. The idea was probably to increase the response speed to port changes. I think that could probably be changed to ground instead of -5V and still work. The more I look at the CV hardware, the more I think that their hardware people were just as goofy as their software people. (I was able to optimize over 1K of the 8K ROM and still have it work with cartridges that didn't use the vector addresses. The worst offender was probably EX DE,HL as six LD instructions when it's a freaking 8080 instruction, GMAFB.) I mean, the 4416 DRAM was pretty much required by using the a 9928, I'll give them that. The VBL->NMI was outright stupid, and a few more bus signals on the cartridge port would have been nice, but that controller port design really is goofy. I have to wonder if that -5 volts explains why I've found so many CVs with blown controller input buffer chips. Edited June 11, 2011 by Bruce Tomlin Quote Link to comment Share on other sites More sharing options...
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