ralphb Posted March 28, 2019 Author Share Posted March 28, 2019 Oh, now I see. Yes, you need either jumper of resistor -- otherwise, the signal is missing from the bank switching circuit! Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted April 5, 2019 Share Posted April 5, 2019 That resistor normally just keeps the cartridge reset circuit from being a dead short when cartridges are inserted into the console. It is such a low value to ensure it doesn't do much to interfere with the signal, but if it isn't present, you would need the shorting wire across the pads to ensure the reset circuit actually forces a reset. Quote Link to comment Share on other sites More sharing options...
ralphb Posted April 6, 2019 Author Share Posted April 6, 2019 (edited) Jim, that's true for the connection between RESET and -5V, but this resistor has a different purpose. It's used for bank switching, and dates back to Atarisoft cartridges. You can read all about it in this earlier post: http://atariage.com/forums/topic/250540-flash-rom-cart/?p=3549738 Back then there was an issue with incorrectly wired capacitor and resistor. Besides the incorrect wiring, it also turned out that modern components are so fast that the FlashROM doesn't need resistor or capacitor. But since you need to have something connecting the signal in the cart port to the 377 doing the switching, I just said keep the resistor. EDIT: clarification Edited April 6, 2019 by ralphb 1 Quote Link to comment Share on other sites More sharing options...
seastalker Posted June 5, 2019 Share Posted June 5, 2019 I saw the YouTube video for the SDD 99 running a GROM cartridge but it is months old. If you don't want to build one, is the FinalGROM99 from the Brewing Academy the one way to go or are their other options? 1 Quote Link to comment Share on other sites More sharing options...
ralphb Posted June 5, 2019 Author Share Posted June 5, 2019 If you don't want to build one, is the FinalGROM99 from the Brewing Academy the one way to go or are their other options? My FinalGROM 99 is the successor to the FlashROM 99. The FinalGROM runs ROM, GROM and mixed ROM/GROM cartridges, and features 1 MB of RAM for images, among other improvements. You can get it from me via email, from Arcadeshopper (who sells my carts), or various other sellers offering clones of unknown quality throughout the web. The demo you saw could only handle single-bank GROM images, at least at the time. If you don't need an SD card for supplying images, there's also the very capable UberGROM (also at Arcadeshopper). 1 Quote Link to comment Share on other sites More sharing options...
GDMike Posted June 13, 2019 Share Posted June 13, 2019 its too bad that a small part of that SDcard in FG99 can't be used as scratchpad to perm storage. As in allowing the minimemory to actually be emulated. As the way MM works in FG99 it loses memory stored on power down. Quote Link to comment Share on other sites More sharing options...
PeteE Posted June 13, 2019 Share Posted June 13, 2019 its too bad that a small part of that SDcard in FG99 can't be used as scratchpad to perm storage. As in allowing the minimemory to actually be emulated. As the way MM works in FG99 it loses memory stored on power down. Actually it can, using a modified MiniMemory binary, with an additional menu entry to save the contents back to the SD card. 2 Quote Link to comment Share on other sites More sharing options...
GDMike Posted June 13, 2019 Share Posted June 13, 2019 ill try the .bin again, i did try a version yesterday and had no luck. maybe it was an old .bin..thank you very much for this change! it only makes sense and if i knew more i would have done something similar!! again, thanks sir. Quote Link to comment Share on other sites More sharing options...
ralphb Posted June 14, 2019 Author Share Posted June 14, 2019 ill try the .bin again, i did try a version yesterday and had no luck. maybe it was an old .bin.. There was some discussion a while ago about the FinalGROM overwriting some bytes in the RAM area when writing back to the SD card. The solution was first to change the addresses of those bytes, but later it occurred to me that I just needed to read those bytes first. To be honest, I'll have to recheck which version I'm shipping now with the FinalGROM. I may also have to re-create the Minimem image. BTW, this thread is for the older FlashROM. For the FinalGROM, see here. Quote Link to comment Share on other sites More sharing options...
GDMike Posted June 14, 2019 Share Posted June 14, 2019 (edited) its cool. BTW i put tape diwn that reset line and its still resetting on me..i looked at that layout showing pins..i went ahead and tried covering both sides of pin 1, like 1 and 2 anyway..but naaa..its gotta be me or maybe the tape is sliding...hmm maybe try whiteout... Edited June 14, 2019 by GDMike Quote Link to comment Share on other sites More sharing options...
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