Re: Image instability with STE booster and system memory over 512k
Posted: 25 Oct 2023 16:56
I think it could definitely be a variation of that problem. @exxos do you have any more of those buffer boards in stock?
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I think it could definitely be a variation of that problem. @exxos do you have any more of those buffer boards in stock?
I have to say that looks nothing like the clock wire I have. I'll try to get a pic and post it.DementED wrote: 25 Oct 2023 16:45Thank you. Looking forward to seeing it. Just to confirm, I'm using the clock wire that came with the Exxos kit. I tried running it exactly as shown in the post with installation instructions here on the forum (i.e. A bit closer to the SIMMs) but this made the interference worse.rubber_jonnie wrote: 25 Oct 2023 16:17 Personally I think your clock wire is too long and it's also going past the main power input, the large capacitor and numerous other components.
I've installed two boosters now, and run 4MB of RAM in both machines, and I don't have any issues, but my clock wire is the original in both cases and runs the shortest route possible.
I'll try and find a picture, or take a new one.
I'll try to find some micro_coax cable. @exxos is there any that would be approved for use here? You mentioned before that different wires create a different kit and would be an experiment.Steve wrote: 25 Oct 2023 12:43 It's got to be something to do with noise on the clock line. All I can suggest is perhaps source some micro-coax which has shielding, solder one end of the shielding to ground leave the other end unsoldered. Then run it the same as you have before, or try even more directly since the shielding should absorb any electrical noise.
Thanks again.
Yes possibly, but it's still very long and goes via a lot of components, would be better shorter.Steve wrote: 25 Oct 2023 19:53 @rubber_jonnie are you looking at the tubing he put the wire inside I guess?
I think I saw them the other day. They never been sold officially as it was just a beta test fix. It's hard to say how widespread problems are as not many do tests and try fixes out.DementED wrote: 25 Oct 2023 16:56I think it could definitely be a variation of that problem. @exxos do you have any more of those buffer boards in stock?
Thank you @exxos . Please let me know if you do find them and I'll happily pay your costs for one. I'm using non-parity SIMMs.exxos wrote: 25 Oct 2023 21:39I think I saw them the other day. They never been sold officially as it was just a beta test fix. It's hard to say how widespread problems are as not many do tests and try fixes out.DementED wrote: 25 Oct 2023 16:56
I think it could definitely be a variation of that problem. @exxos do you have any more of those buffer boards in stock?
Don't mess with the 32mhz wire. You need to use the one which came with the kit. Using any other wire will change its capacitance and impeedence and will cause all sorts of new issues.
Keeping the wire away from the ram is the main thing. But it's still unknown why that even causes problems in the first place. I know parity Simms cause all sorts of problems. I can only assume that coupling on the 32mhz wire causes random GND bounce somewhere which skews timings just enough to cause huge malfunctions. That's known as even a X10 probe is enough to cause chaos.
It's possible why changing the RAM amount is have such changes as it's changing the current though the grounds. A few pF in the wrong place and a change of just 1ns is enough to break timings. The STE seems to be gaining traction for being the worst ST these days !
Ok, understand the shroud, but you're still running it by the power connector and the large cap etc and I'm wondering if the extra power load caused by additional RAM (Although I know it isn't a lot) is what the problem is and your 32Mhz cable is picking it up. The shroud will probably not help with EMI if it's just tubing.DementED wrote: 26 Oct 2023 09:31Thank you @exxos . Please let me know if you do find them and I'll happily pay your costs for one. I'm using non-parity SIMMs.exxos wrote: 25 Oct 2023 21:39
I think I saw them the other day. They never been sold officially as it was just a beta test fix. It's hard to say how widespread problems are as not many do tests and try fixes out.
Don't mess with the 32mhz wire. You need to use the one which came with the kit. Using any other wire will change its capacitance and impeedence and will cause all sorts of new issues.
Keeping the wire away from the ram is the main thing. But it's still unknown why that even causes problems in the first place. I know parity Simms cause all sorts of problems. I can only assume that coupling on the 32mhz wire causes random GND bounce somewhere which skews timings just enough to cause huge malfunctions. That's known as even a X10 probe is enough to cause chaos.
It's possible why changing the RAM amount is have such changes as it's changing the current though the grounds. A few pF in the wrong place and a change of just 1ns is enough to break timings. The STE seems to be gaining traction for being the worst ST these days !
It's annoying because I have 2 later model STEs that work perfectly (but they don't have the socketed CPUs).
@rubber_jonnie the purple tubing is the shroud. I don't want the wire to go any closer to the RAM as that causes more problems.
Can you PM me your address.DementED wrote: 26 Oct 2023 09:31 Thank you @exxos . Please let me know if you do find them and I'll happily pay your costs for one.
Yep. I will check shortly.exxos wrote: 26 Oct 2023 10:17
@rubber_jonnie it would be useful to know what motherboard and shifter number you have in your machine.