Got new 64mbit RAM modules but have some problems

Got new 64mbit RAM modules but have some problems
by pcmantinker on 2009-08-20 (#50098)

I just received my SF7 RAM modules today and put them into my SF7 to test. They test as good, but when I try to load a game from a floppy disk to them, I get RSDT error. I tried my old 32mbit RAM again and the games loaded fine. The RAM modules that I got were the re-manufactured ones that Tototek makes and not the original Bung RAM modules. Would that have any effect on this issue?

Also, I tried sending neviksti's Star Ocean over my parallel cable and it failed at 8%. I am using Windows XP SP3 on my desktop. I have tried using Windows 98, 2000, and Linux Ubuntu and get similar issues with other games larger than 8mbits. I may not have quite the correct parallel transfer setup, but I will work on getting something in the future if need be.

EDIT:
After a little more troubleshooting, it appears that the SF7 draws more current when using 64mbit RAM modules than when using 32mbit RAM modules. I tried using my floppy drive with my 32mbit RAM module and it performed all disk operations successfully. I also tried using my floppy drive without any RAM in the system and it performed disk operations fine (aside from loading a game). I think that my power supply for my SF7 is 9V at 850mA. I am going to try and get another power supply that has more current output and around 9-10V. I think that I've read you can use the Sega Genesis adapter? And the max amperage is around 1.0A for the SF7? I will let you know on my findings.

by Hojo_Norem on 2009-08-21 (#50126)

I use a Mega Drive wall wart on my SF7 and it works fine so you shouldn't have any problems if you can find one (I use 2 x 64MBit modules in my SF7).

Also, if you plan on using your SF7 regulary then it might be a decent idea to look into getting or building a CD-ROM unit for it. The required CD Drive usually popus up on eBay now and again and if you have a little confidence with electronics then the interface itself isn't that hard to build.

Loading Star Ocean from CD-R is far better then tethering you SF7 to your PC. I mainly have the NTSC versions of the PAL games I own and I just keep a floppy in the drive to store all my battery saves.

by MottZilla on 2009-08-21 (#50135)

The MegaDrive/Genesis Model 1 adapter is ideal for the GDSF series. 9V DC at 1.2amps. Plenty for the copier. That RDST error also comes up if you are trying to write to a disk that has the copy protection tab in the protected position I think.

by pcmantinker on 2009-08-21 (#50137)

So, it appears as though my troubleshooting was correct. I bought a Sega Genesis power supply and attached the ending from my old power supply to it and now games load perfectly from floppy disks. When I get the chance, I'll need to solder the connections to make them permanent, but it works.

by MottZilla on 2009-08-21 (#50149)

Attached the ending? Soldering? Why couldn't you just plug the adapter into the back of the GDSF?

by pcmantinker on 2009-08-21 (#50150)

The fitting wasn't the same size. I found it at a local used game store for $6. I think it was a good deal considering that something equivalent could cost around $20 from Radio Shack. I know it's kind of a hack fix, but it works.

by MottZilla on 2009-08-22 (#50154)

I still don't understand how that could be. The Sega Model 1 power supply will fit the power jack on the GDSF. You shouldn't have to hack anything apart to connect it. But if it works I guess it doesn't matter.

by pcmantinker on 2009-08-22 (#50155)

I don't think that I got the Sega Model 1 power supply. I purchased the adapter before reading your initial reply.

by orwannon on 2009-08-25 (#50196)

MottZilla wrote:
The MegaDrive/Genesis Model 1 adapter is ideal for the GDSF series. 9V DC at 1.2amps. Plenty for the copier.

Thanks for the hint, MottZilla. This works for the DX2 as well!