sideburn

Yeah the ones for the 520 usually have a daughter board that sticks on top of the mmu and it’s unreliable and can damage the socket. The best one I’ve seen is the board that attaches to the motherboard directly where the ram normally goes. you remove all the ram chips and replace it with this board. The board has two DIMMs on it brining it to 4mb https://github.com/agranlund/STRam problem is you have to order the board from PCBWAY or oshpark etc. then find the ram chips. Likely off of some simms and remove them and pull all the rams off the main board etc. it’s a project.

Yeah I thought you did. well I purchased a new logic board for the 520 and I don’t know what I’m going to do at this ping with it. I was thinking of leaving not as is with 512k and try to find an sf314 and just keep it stock. I could do that new ram upgrade but it’s a lot of work. You have to find some sim rams get the PCB and build it and then pull all the rams off the main board. It’s a huge ordeal.

Indeed it is. Only ST experience I had was in 1990 I bought an ST off a guy at work that modded it to run Mac OS. I still have it but it’s got the piggy back ram mod and only sees 512K and I think I’ve isolated it down to a bad ram. I’ve swapped all the socketed chips. With 512k I can’t do anything with it without a floppy drive. Nothing on the US disk runs. I remember we wire wrapped some mod board to an ide drive to make it run the Mac roms somehow but I cannot remember any details. It booted straight into system 6. There was no cartridge or emulator software that I can recall and no other splash screens or menus other than system 6. It was my poor man’s Mac at the time and never used it as an ST system til now.

Got it all dialed in now. Repaired and restored STacy with nice and bright NOS display, NOS keyboard so all keys work and fresh new Mylar, new button cell RTC battery moved to the battery bay, external US with three 512MB partitions, loaded up with a handful of games, programming tools, and Cubase 3. now to drag out the old Emax II midi synth!

Yeah I figured I’d convert my external to an internal when my stock driver kicks the bucket. Min going to order that adapter. I asked him if there’s any difference between my cased board and the internal board and it’s just the power connector. Right now it’s kindof nice having an all original Stacy and being able to toggle back and forth between the internal drive and the US. Just having to rename the shdriver.sys and boot off a floppy is kindof clunky. Be nice if there was a software solution. One thing still puzzling me is the sd card from lotharek works but the generic satan.img (from lotharek faq page) i have on a second sd card gives me a system bomb on the STacy But it works on a 520st. Can’t figure out what the differences are other than the lotharek sd card is preloaded with games and stuff. both of these images are the PPera drivers. what’s the benefit with the HDDriver?

Hey all, Just an update on what I've figured out: A) My internal drive is just giving out once in a while and i have to give it a smack and it comes back. B) I figured out how to get the US to boot. First I made a bootable floppy with SHDRIVER.SYS on it it and then if I rename the SHDRIVER.SYS on the internal drive C : to SHDRIVER.BAK so that the internal drive doesn't mount, the external US mounts instead. Then when I want to switch back to the internal drive, I boot from the floppy which mounts the internal drive.

Oh yeah it was a blast. I can’t wait to do it all over again! hmm I see on lotharek that there’s an internal board that’s different.

Ok thanks for the info. Is the US inside the metal “cased” version different from the internal version of the board? I was hoping I could just take the US board out of its metal case and 3d print some kind of mount for the STacy to make it internal. Yeah, the bummer is I just put the STacy back together. I replaced the display with a NOS one and fixed the keyboard. I also replaced the RTC clock battery and put a button cell / holder inside the battery bay. I also had the goo on the drive and it had oozed onto the side cover plate and ate the paint off. I had to sand it down and re paint it. now the HD is acting up. what’s weird is if I plug the US into the back, and leave the US turned off even, the drive starts it’s spin up / spin down issue. I smack the side and it starts working again. but it’s odd that plugging the US into the back causes it to act up. Makes me wonder if theres a power / amps problem somewhere other than the drive itself.

ahh thanks for the info and link to that conector. That looks like it could work.

Well I’m 11 years late to this party. mid anyone is still around can you tell me if the “Ultrasatan adapter for Mega STE” from lotharek will work in the STacy? It looks different than the one in this thread and doesn’t supply power. Looking for a plug and play solution. Here is a link to the cable I am asking about: https://lotharek.pl/productdetail.php?id=49 I currently have the metal cased US with a cable and adapter that plugs into the external DMA port on the back of the STacy. It works but my internal drive has started to act funny. It spins up and back down at times and I have to whack the side of the STacy to “fix” it so I’m considering converting my cased US to an internal drive in the STacy.

OMG that idiot in here LOL! I have a 520ST that has that old piggy back ram upgrade he was talking bout and it’s failing. So it’s near impossible to try to fix and find which ram is bad so I want to also do this new modern upgrade (as seen on Adrian’s digital basement, don’t add sockets!)… Do we have a best path to both ordering the board as well as sourcing the parts and RAM now? did you use OSH park or PCBWAY? was the upgrade a success?

Haha I’ll have to check the bottom of the STacy. Good point since 12 1.5v would be 18. The supply puts out 16.5. I tested it.

Well this is a first. Good thing I put a fuse on my circuit. OEM STacy PSU label says its center positive on the barrel Jack. It’s center negative. I was making a battery pack for it and it popped the fuse and left me scratching my head.

Yeah I have a gotek in my Amiga. The situation is this has become a rabbit hole money pit. FIRST, I bought an Atari STacy computer. It has 4MB of ram. All good. Next, I bought an external US drive for it and it didn’t work with it and made the internal drive go bonkers. Luckily it came back to life. So then I dragged my 520 ST out of the closet that hasn’t been turned on for over 30 years to see it will see the US drive and if so, I could try changing the drive IDs and see if that solves the problem with the STacy. It did see the US and I did change the drive IDs but no luck working on the STacy. And since the 520ST (which has the piggy back 1Mb ram but is only seeing 512k) cannot run any of my software on the US and neither can the STacy, I am STILL hosed! And now I have a new issue with the damn ram upgrade not working on the old 520 so THEN I bought a brand new 520ST board to trouble shoot the other one and also rule out any bad ram issues or whatever might be the problem on the original board but now that new board also cannot run any software off the US. so I’m still screwed with a brand new 520 board and a brand new US drive and a STacy that’s still a pain in the but to get software into its internal harddrive… …which I am doing by finding floppy disk images online, then using a greaseweazle to write them to actual floppies using the Amiga floppy drive that I had previously removed and replaced with a gotek and connecting that with a greaseweazle to my PC laptop. 😂 🤦‍♂️ so yeah, now all I need to do is buy and external floppy for the 520 wich are crazy expensive. oh and yeah, I have a new problem to solve with the original board’s RAM issues. Hahah. Probably the smart thing to do is throw in the towel and sell all my ST stuff. But I’m not very smart and for some reason am fixated on solving problems.

I’m using the PP drivers that the US came with on a pre prepped sd card. No auto folder but I do have that free memory ACC file still. I’ll remove that.

Thanks everyone. Yes none of the pre installed US HD stuff works. I’ve had a tiny bit of luck with converted .st image files / prg programs. I’ll try to hunt down some more, really just looking for some things to prove out that the machine is stable.

BTW I was initially using this same ram test it never shows errors even on my other board that has the piggy back ram upgrade and it’s not seeing the upper banks of memory and it keeps crashing as if there’s a ram issue. So not sure how reliable that yaart ram test program is.

I will try some more. I’ve tried a few already with not much luck. one problem is all I have is the ultrasatan. I don’t have a floppy drive.

Well I know not booted directly into Mac OS. I never had any menus or any “spectre” splash screens.

Just found out about Dave Small and his emulators. Back in 1990 a guy at my work helped me turn a 520 ST into a mac. I still have the ST but I opened it up and the only mod it has is a piggy back ram upgrade. I remember it had a customization hard drive (I think it was and IDE drive) that had this breadboard on it with tons of wire wrapping all over it. I think this board had Mac ROMs on it. I don’t recall having anything that plugged into the cartridge port and I’m pretty sure the 520 would boot directly into Mac system 6. I wonder how that worked now and wish I could fond it. Now I’m wondering if there’s some connection to it being either a Spectre GCR or some hack or some connection to Dave and his software. I recently powered the 520 up and it runs but can’t see the full 1MB bit boots up into GEM. Anyone have any ideas about how my wire wrapped “mac” hard drive worked?

I see. Ok son when I’m power up cat e the CAS goes low once and I’m not noticing. Is there any way to find out which RAM chip might be the problem?

Yes it is now but SysInfo wouldn't run prior to me getting there Desk Accessory.. I got that just to have something that could see the RAM

I found a copy of v4.04 and that one runs. It is showing 318K available and 512K total. It is showing TOS using 192K Is this normal? And if so what, if anything will run on this machine with only 318K? So far I haven't had any luck getting any games to work.

Hey all, I have a brand new stock 520 ST board I bought as a diner to troubleshoot another one that has a faulty RAM upgrade and neither of them are able to run SysInfo. It says I need at least 250K to run sysinfo (v8.4) I installed a desk accessory to show me how much ram I have and it says 326K on the new board and 325K on the faulty board. I believe it is running TOS 1.04. They are both Rev H boards. I need to be able to get info on these boards, especially info on the RAM. Any ideas why it doesn't have enough RAM to run SysInfo and is there an older version or some other software I can get to diagnose these boards? Thanks.

Me neither. Well the soldering all loos good. It’s odd that both the upper and lower bank are not working. I need to figure out what tos does to “see” the ram. Not sure what CAS / RAS do exactly. I thought CAS were chip selects. it’s also strange that the full 1mb showed up once. And the. After reseating chips it went away.