JGRAHAM2

That upgrade installs with the Antic chip which is under the CPU in the 130XE. There isn’t room with Rapidus installed, but I have a 40 pin ic relocater that may work.

Or I could install Jurgen’s 576K upgrade that includes base memory. Right now, the 512K external does the same thing, so I’ll keep working with that for awhile.

I just installed a 64K SRAM upgrade in the 130XE and Rapidus is working great. Of course I lost 64K of extended memory, but it also works with my external 512K upgrade from Zaxon, so no problem. I can use my FujiNet with it in Classic mode. (Haven’t tried it in Rapidus mode for that) I did connect extselect on the 64K. I haven’t had a glitch so far.

Ok, so I used my SysCheck II set to use 64K base RAM rather than borrow from my 600XL. It is working pretty much flawlessly, both in Classic and Rapidus modes, so far. I will let it run longer to see how it goes, but already it is more stable than ever.

What I am seeing is lockups and corrupted screens after it runs for awhile. Other times it can run for an hour with no issues. The CPU is NCR and I’ve tried 2 of those, plus added a small heat sink. It really doesn’t like EPROMs. I tried an alternate OS and it completely bypassed the Rapidus boot up screen and went directly to the Atari screen. I didn’t try a EEPROM though. I just wanted a ROM under classic mode that booted without BASIC and ran high speed disk.

But why are some computers stable? I ran tests on this one before the install. I only ran a few cycles, but it tested good. It does have the original MT RAM except a couple I replaced because they failed.

Results so far are mixed. It is better, but still not good enough. I wonder if the base RAM is the issue. I do have chips and a tester, so I’ll look into that. I’ll test in place first with my Syscheck II. I’m also thinking about borrowing a 576K SRAM (Jurgen) from one of my 600XLs. That would replace the base RAM with SRAM….

Encoders generate a square wave, so I wouldn’t think that would work without additional electronics.

Right, I haven’t done any of the suggested improvements to the reset circuit yet. Also, it doesn’t seem to lockup so far when it is running for awhile. I’ll report back on that once I have let it run longer.

I did install switches instead of jumpers on a couple of mine.

It has definitely made it more stable. It never fails to boot now. It has always been intermittent on that, often corrupting the screen even on the progress bar. We’ll see how it goes.

Update: more testing required, but using my external RAM expansion from Zaxon, so far, it’s been completely stable. Fingers crossed. If this proves correct, I will install Jurgen’s internal SRAM expansion.

@drac030 Thanks, is there any other firmware I should update?

What I am seeing so far is that it is much more stable in Rapidus mode. I still need to do some more tuning though.

I am going to run as is for awhile until I am familiar with it. How are you using it? Anything that uses the extra speed or other features? Any problems you had to overcome as you did the mods? What firmware versions are you running?

Thanks, once in a while it doesn’t boot after the progress bar reaches 100%. A reset usually works for that. I’ll look at the other things you mentioned, but the CPU is the NCR version.

Here are my 3. The first 2 are stock, the last, 51438 has super video, RAMBO 256 and 32 in 1 OS.

Thanks!

@flashjazzcat Thanks, I’ve looked at this. I updated the firmware to the one posted by Lotharek. Looks like Draco has a newer MODULE.ROM. I’m not sure how to check the PBI0 as he recommends. Is it likely this one is different? It originally had the Sept 2016 version of the firmware I believe. It is now Nov 2016

@Beeblebrox Thanks, I’ve seen his videos which cover the issues with U1MB, which is why I didn’t add this to one with that mod. (I highly respect his expertise and have learned so much from watching his mods and repairs. I like to watch videos, like his, that include the mistakes or failures as well as the successes. Adrian’s Digital Basement is another.) I am hoping development continues for this device. I have 8 130XEs right now, as well as a spare board, so I can keep this one to play with the Rapidus. The mod has no irreversible changes to the motherboard or case, so if I need to, I can remove it. (Other than the socket and I consider than an enhancement.)

Thanks @Stephen, time will tell as to whether I agree with you. One question, did you ever use it with no other mods? This is not advice as I’ve only just installed it. It’s just a question.

Thanks for designing the case, it works great. Now I need to learn to make the awesome labels.

I’ve seen quite a few posts about incompatibilities of Rapidus and other complaints, but I’d like to see some constructive discussion on installation and use. I’ve just installed it in a 130XE with no modifications other than desoldering the CPU and installing a precision socket. I tried it first on my almost fully socketed board, but the double wipe socket on that board definitely was a problem. I then moved it to my spare board after installing the socket. That was much better and was even better when I used wire ties to hold the precision socket stack tightly together. See the picture on where I connected the 3 wires. This was on the first board before I moved it to the one with the precision sockets, but I did that one the same on the wire solder locations. I welcome comments, but I would really like to see this thread as a go to for Rapidus tips rather than venting.

Yes, that was it! Thanks

Has anyone built this cartridge? I built the short version and it does not work. I used precision sockets so I could troubleshoot if needed. I tested all ICs and they look good. I reflowed all solder connections. All I get is a greenish screen on my 800XL and 130XE. I get nothing on the 800. I tried a ST M27C512 EPROM and a Winbond W27C512 EEPROM with the same result. I am using the bin file the creator posted. Any ideas? I tried posting on PCBWAY, but it doesn’t seem to work. Using my iPad so that could be it.