Help resolving STE Booster instability?

Problems with your machine in general.
User avatar
IngoQ
Posts: 490
Joined: Tue Aug 22, 2017 8:38 am
Location: Germany

Help resolving STE Booster instability?

Post by IngoQ » Sat Oct 07, 2017 1:30 pm

Hiya,

I'm in the process of fitting my STE Booster and it seems like the machine is quite instable, when switching to 32MHz. I am trying to figure out a scheme, but I have the gut feeling that it has to do with the 32MHz wire to U405. When I change the position of the wire, the stability improves slightly.

I tried using a shielded cable, but it made the instability worse, for some reason...

In addition, when swapping out the SIMM modules, stability again improved by a margin. But the machine still runs for a couple of minutes, and when starting GB6 it randomly crashes after some tests

I double, tripple and quadruple checked every connection and solder joint, and am a little lost here... Did anyone encounter something like this, and has a hint?
Ingo :geek:

“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.” - Antoine de Saint-Exupéry

User avatar
IngoQ
Posts: 490
Joined: Tue Aug 22, 2017 8:38 am
Location: Germany

Re: STE Booster instable

Post by IngoQ » Sat Oct 07, 2017 3:07 pm

To further harden my theory about the 32MHz cable:

I temporarily "routed" the cable over the modulator and then downwards right hand of the SIMs. The STE just completed 30 full GB6 cycles in 32MHz without crashing...

So what do I do now? Using a shielded cable? What type of cable? Any ideas?
Ingo :geek:

“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.” - Antoine de Saint-Exupéry

User avatar
exxos
Site Admin
Posts: 2211
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: STE Booster instable

Post by exxos » Sat Oct 07, 2017 4:16 pm

U405 what is the exact number ? You need the F version, not S.

Also you need 8 chip simms, not parity 9 chips.

as for cable, just use the thin black cable i supply in the kit, and route it from the ic downwards, then across the front of the simms to the booster.

Only time I saw issues with moving the wire was when using parity simms. Other wire locations just caused video interference.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

User avatar
IngoQ
Posts: 490
Joined: Tue Aug 22, 2017 8:38 am
Location: Germany

Re: STE Booster instable

Post by IngoQ » Sat Oct 07, 2017 7:25 pm

exxos wrote:
Sat Oct 07, 2017 4:16 pm
U405 what is the exact number ? You need the F version, not S.
Yep, checked that before I began, it's the 74F257.
exxos wrote:
Sat Oct 07, 2017 4:16 pm
as for cable, just use the thin black cable i supply in the kit, and route it from the ic downwards, then across the front of the simms to the booster.
Nope, no cable in my kit, but I have plenty of thin black wire here, so no issue. I used that first, and then (out of desparation) tried a thicker one, which made it worse. Thicker antenna, I guess ;)
exxos wrote:
Sat Oct 07, 2017 4:16 pm
Also you need 8 chip simms, not parity 9 chips.
Only time I saw issues with moving the wire was when using parity simms. Other wire locations just caused video interference.
Yep, that's it :bravo: .
I remember the discussion about parity simms, and whethere they have an effect. Turns out that both my sets are partity (4MB with 9 modules, 2MB with 3 modules). I guess this settles the debate then ;)

I only have some EDO-Rams lying around, so no quick fix then. Luckily I know an excellent store, that has newly made SIMMs on stock....that I just ordered :cheers:

While waiting on these, is there a temporary way to convert parity to none parity modules? Like cutting traces on Pins 26, 28 and 29 or removing one module?
Ingo :geek:

“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.” - Antoine de Saint-Exupéry

User avatar
exxos
Site Admin
Posts: 2211
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: STE Booster instable

Post by exxos » Sat Oct 07, 2017 7:40 pm

IngoQ wrote:
Sat Oct 07, 2017 7:25 pm

Yep, that's it :bravo: .
I remember the discussion about parity simms, and whethere they have an effect. Turns out that both my sets are partity (4MB with 9 modules, 2MB with 3 modules). I guess this settles the debate then ;)
IIRC "rubber_jonnie" also had similar issues.. Yes, I did tell people "elsewhere" about such issues..

IngoQ wrote:
Sat Oct 07, 2017 7:25 pm
While waiting on these, is there a temporary way to convert parity to none parity modules? Like cutting traces on Pins 26, 28 and 29 or removing one module?
You can remove the 9th chip, think its pin 30 end, just heat gun it out...
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

User avatar
exxos
Site Admin
Posts: 2211
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: STE Booster instable

Post by exxos » Sun Oct 08, 2017 1:29 pm

Actually..


4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

User avatar
IngoQ
Posts: 490
Joined: Tue Aug 22, 2017 8:38 am
Location: Germany

Re: STE Booster instable

Post by IngoQ » Sun Oct 08, 2017 2:49 pm

exxos wrote:
Sat Oct 07, 2017 7:40 pm
You can remove the 9th chip, think its pin 30 end, just heat gun it out...
Tried that, but not much change. It still gets instable to the point of not booting, when the cable comes too close to the board on pretty much any spot. Only when I have it at least 5 cm away, it works.

I'll wait for the SIMMs to be sure. If the problem still persists, I will have to think about some sort of shielding... maybe a coax cable? I am wondering, if I HAVE to connect the shield to ground...
Ingo :geek:

“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.” - Antoine de Saint-Exupéry

User avatar
exxos
Site Admin
Posts: 2211
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: STE Booster instable

Post by exxos » Sun Oct 08, 2017 5:40 pm

IngoQ wrote:
Sun Oct 08, 2017 2:49 pm
Tried that, but not much change. It still gets instable to the point of not booting, when the cable comes too close to the board on pretty much any spot. Only when I have it at least 5 cm away, it works.
I only saw that with parity simms. Basically something else must be floating somewhere.

IngoQ wrote:
Sun Oct 08, 2017 2:49 pm
I'll wait for the SIMMs to be sure. If the problem still persists, I will have to think about some sort of shielding...
Yes probably the best idea for the moment.
IngoQ wrote:
Sun Oct 08, 2017 2:49 pm
maybe a coax cable? I am wondering, if I HAVE to connect the shield to ground...
No, dont screen the cable. a few pF on a long cable at 32mhz will drop the 32mhz down to 1 volt and cause massive ringing. You shouldn't need to go to those lengths anyway. something is at fault somewhere which is only showing when the 32mhz line is close to the fault. The 32mhz line isn't at fault (unless you can scope it and see massive ringing)

I have tried all routes with the 32mhz line, all over the board, and never seen any stability issues, only with parity simms. I tried 40 of them and the fault was replicated and solved on every simm.

If your PSU recapped ? One possibility. Or maybe you have some simms which still do not like the 32mhz wire near them for some reason. What speed are they ?

Also assume you have my dual tos board and connected the CE cable correctly to the ROM board ? Have you tried 8mhz mode to see if its stable ?

I would suggest if the new simms don't solve the issue, you send me the motherboard to diagnose.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

User avatar
rubber_jonnie
Posts: 281
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: STE Booster instable

Post by rubber_jonnie » Sun Oct 08, 2017 11:23 pm

I did have some strange memory issues, but luckily I had a big bag o' ram from back in the old days, and found some suitable 8 chip SIMMs that worked fine.

In terms of the 32Mhz wire, I came pretty much direct from U405, across the top right of the SIMM sockets (You should be able to see in the picture), and direct to the Booster, using the wire supplied with the kit, but keeping it as short as possible.

It was only the SIMMs that caused trouble in my case though, as once swapped out for a different set, it was all stable.
Attachments
IMG_20160802_223606.jpg
IMG_20160802_223606.jpg (4.55 MiB) Viewed 619 times
Collector of old Atari things:
800XL + Ape Warp mod, 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, 2600jr, 7800 and Lynx II
Atari 520ST + Gotek, 1040STF, 4160STE with 32Mhz booster, ROM switcher and CosmosEx
Plus the rest..
C64 + 1541 and cassette, 2x Sinclair QL, Mac Classic, Mac Performa 6200, Amiga 1200, ICL One Per Desk, Epson HX20, Dreamcast, original Xbox, SNES and a bunch of other bits n bobs I can't remember right now. :D
www.electronicnothingness.co.uk

User avatar
IngoQ
Posts: 490
Joined: Tue Aug 22, 2017 8:38 am
Location: Germany

Re: STE Booster instable

Post by IngoQ » Mon Oct 09, 2017 7:28 am

exxos wrote:
Sun Oct 08, 2017 5:40 pm
No, dont screen the cable. a few pF on a long cable at 32mhz will drop the 32mhz down to 1 volt and cause massive ringing. You shouldn't need to go to those lengths anyway. something is at fault somewhere which is only showing when the 32mhz line is close to the fault. The 32mhz line isn't at fault (unless you can scope it and see massive ringing)
I tried using a shielded network cable, results were better, but the issue remained. So I switched back to thin black wire ;) Still have no scope, so no idea, how the signal looks like... :(
exxos wrote:
Sun Oct 08, 2017 5:40 pm
If your PSU recapped ? One possibility.
It's a DVE DSP-508A, modified to your specs.
exxos wrote:
Sun Oct 08, 2017 5:40 pm
Or maybe you have some simms which still do not like the 32mhz wire near them for some reason. What speed are they ?
Yeah, most likely. I guess the remaining traces still act like an antenna. This would be conclusive with the fact, that stability improves, when I only use two of the modified SIMMs, and again when I use 3 module SIMMs (with parity), which is the most stable. I guess, as soon as I have the non parity SIMMs, we'll know.
exxos wrote:
Sun Oct 08, 2017 5:40 pm
Also assume you have my dual tos board and connected the CE cable correctly to the ROM board ? Have you tried 8mhz mode to see if its stable ?
Yes, and yes. 8 MHz is perfectly fine.
exxos wrote:
Sun Oct 08, 2017 5:40 pm
I would suggest if the new simms don't solve the issue, you send me the motherboard to diagnose.
Thanks for the offer :)

There is another possibility, that my CPU-socket construction, which exposes CPU lines vertically for about 5-8mm will be of fault here. When I can rule out the SIMMs I will have to investigate this. It turned out way to high anyways, so I will have to start over with that.
Ingo :geek:

“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.” - Antoine de Saint-Exupéry

Post Reply