+Mitch Posted March 9, 2010 Share Posted March 9, 2010 Which instructions are you using? Which RAM Cart version are you building? What is the part number on the board you are using, it should start with a C.I am using the instructions for the 48K RAM cart from "devkit2.zip" the board's P/N is C100339 The C100339 board should work fine, it's what I used when I made my 48K RAM cart. You may want to double-check all of your connections. Mitch Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 9, 2010 Author Share Posted March 9, 2010 The C100339 board should work fine, it's what I used when I made my 48K RAM cart. You may want to double-check all of your connections.I've checked them over several times now, they are fine. I am using a Hitachi HM628128LP-85 SRAM chip. Are there supposed to be any other resistors or capacitors on the board other than C3 (0.1uF)? Quote Link to comment Share on other sites More sharing options...
+Mitch Posted March 9, 2010 Share Posted March 9, 2010 The C100339 board should work fine, it's what I used when I made my 48K RAM cart. You may want to double-check all of your connections.I've checked them over several times now, they are fine. I am using a Hitachi HM628128LP-85 SRAM chip. Are there supposed to be any other resistors or capacitors on the board other than C3 (0.1uF)? No, just the two chips and one capacitor are all I have on my board. Mitch Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 9, 2010 Author Share Posted March 9, 2010 Just checked the voltage going to the chip, it was 4.94V so that seems fine. Could it possibly just be a bad SRAM chip? Quote Link to comment Share on other sites More sharing options...
+Mitch Posted March 9, 2010 Share Posted March 9, 2010 Just checked the voltage going to the chip, it was 4.94V so that seems fine. Could it possibly just be a bad SRAM chip? Well, I suppose it's always possible. Was it new or used? Mitch Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 9, 2010 Author Share Posted March 9, 2010 Well, I suppose it's always possible. Was it new or used?Brand new from Jameco. Quote Link to comment Share on other sites More sharing options...
gdement Posted March 10, 2010 Share Posted March 10, 2010 Well, I suppose it's always possible. Was it new or used?Brand new from Jameco. According to their site, that item is a "pull" (I think most of their old style RAM chips are) http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=103982 The 70ns version doesn't say pull so I guess those are new. On the C100339 - did you check the setting of all the jumper pads? Something else I'd try is to check continuity between parts very far apart across the cart connector. For example, see if the address/data lines have continuity from your cart RAM chip to the console's 6502, etc. Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 10, 2010 Author Share Posted March 10, 2010 "pull"I didn't notice that.On the C100339 - did you check the setting of all the jumper pads?Wait... the jumper pads make a difference? What are they supposed to be set at? Quote Link to comment Share on other sites More sharing options...
Eckhard Stolberg Posted March 11, 2010 Share Posted March 11, 2010 On the C100339 - did you check the setting of all the jumper pads?Wait... the jumper pads make a difference? What are they supposed to be set at? I just checked the jumper pads on my C100339 48K cart. They are a little difficult to see, but I think W1, W4, W7 and W8 are closed, and W2, W3, W5 and W6 are open. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted March 11, 2010 Share Posted March 11, 2010 Hmm, mine are different. I have W1, W2, W4, W7 and W8 closed. W3, W5, W6 are open. I'll have to look at the schematics again but I don't think some (all?) of the jumper settings don't really matter. Mitch Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 12, 2010 Author Share Posted March 12, 2010 W1, W4, W7 and W8 are closed, and W2, W3, W5 and W6 are open.Setting these didn't make a difference, binaries cannot be uploaded to the cart still. I might as well give up, I'm at a loss what is wrong with it. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted March 12, 2010 Share Posted March 12, 2010 Can you upload games to the 7800's RAM successfully? Also, if you post some closeup front and back pics maybe someone can spot an issue. Mitch Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 12, 2010 Author Share Posted March 12, 2010 Can you upload games to the 7800's RAM successfully?Tried uploading a 4k game, Color Bar Generator, times out every time. Command line used: "7800ctrl -w2000 -tSEND cbg.bin" Perhaps this is where the virtualization is going to completely fail?Also, if you post some closeup front and back pics maybe someone can spot an issue. Quote Link to comment Share on other sites More sharing options...
Eckhard Stolberg Posted March 12, 2010 Share Posted March 12, 2010 Tried uploading a 4k game, Color Bar Generator, times out every time. Command line used: "7800ctrl -w2000 -tSEND cbg.bin" Perhaps this is where the virtualization is going to completely fail? That wouldn't work, because there are only 2K of RAM at address $2000, and part of it is used by the DevOS transfer routines itself. So writing something there would crash the console. You could try writing a 2K ROM to address $1800. Also does using the -f switch make a difference, when writing to your RAM cart? The normal transfer routines try to verify if each byte was written correctly, while the fast (-f) routines don't do that. If writing works with the fast routines but not with the normal ones, it would indicate a problem with your RAM cart or your DevOS modification. If it fails in both normal and fast mode, then it's probably a problem with the LPT cart or the virtualization. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted March 12, 2010 Share Posted March 12, 2010 I was digging through old emails because something about your issue sounded vaguely familiar. Anyway I found an email from Eckhard back in September of 2000 where he mentioned switching the jumper on the back, using hole 2 instead of hole 3 (step 10). After I did that my RAM cart started working. You might give it a try. Mitch Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 12, 2010 Author Share Posted March 12, 2010 (edited) Eckhard, I've successfully uploaded Splatform to the internal RAM by using the following command: "7800ctrl -w1800 -tSEND splat.bin" using the -f switch does not work at all. Took Mitch's suggestion and used the identical command line with my RAM cart (bar the -w switch), did not work at all. Edited March 12, 2010 by vb_master Quote Link to comment Share on other sites More sharing options...
Shawn Posted March 12, 2010 Share Posted March 12, 2010 You need to replace the cap you removed that is to the right of the rom chip (now covered by the SRAM). Just put it on the back of the PCB on the solder side. Thats what I do. Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 12, 2010 Author Share Posted March 12, 2010 replace the capJust replaced the cap and attempted to transfer Splatform to the RAM cart using both versions of 7800ctrl. I've used both the original pin 3 and pin 2 placements on the back of the cart board. The transfer times out every time. Quote Link to comment Share on other sites More sharing options...
Eckhard Stolberg Posted March 12, 2010 Share Posted March 12, 2010 Eckhard, I've successfully uploaded Splatform to the internal RAM by using the following command: "7800ctrl -w1800 -tSEND splat.bin" using the -f switch does not work at all. Took Mitch's suggestion and used the identical command line with my RAM cart (bar the -w switch), did not work at all. Are you using 78ctrl38.exe that was posted in this thread? I just noticed that this version has support for Graham Percy's bankswitched RAM carts and is trying to use them by default. His Geocities site is gone, but there is a mirror at http://www.oocities.com/gjp57/download.htm. If you are using this version of 7800ctrl with a linear RAM cart like the one you build, you need to specify that with the -c1 switch. So "78ctrl38 -c1 splat.bin" should work better (you don't need to specify the -tSEND option, as this is the default as well). And you only need to move the wire from hole 3 to hole 2, like Mitch suggested, if those aren't connected on the other side of the board, like it is with my RAM cart. Quote Link to comment Share on other sites More sharing options...
vb_master Posted March 12, 2010 Author Share Posted March 12, 2010 (edited) Eckhard, I've used both versions. I figured out that 78ctrl38 required the -c1 switch from reading the usage. It seems that hole three is connected to the other side of the board, I've added a small amount of solder to the hole and tinned the upper side of the pad better to ensure connection. Using the command line "78ctrl38.exe -c1 splat.bin" still does not work with my RAM cartridge, yet it does work with the internal RAM when specifying -w1800. Edited March 12, 2010 by vb_master Quote Link to comment Share on other sites More sharing options...
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