zfrenchy wrote: 19 Jan 2026 16:55
I cannot make it to fail this morning !!!! But still not having the ATARI logo and RAM test at boot.
You know you only get the logo with TOS206 ?
OK OK, I know you said before, but my TOS switch is a fail, I put a jumper, and now TOS 2.06 is working.
WAIIA !!! (what an idiot I am)
Re: Booster V4sm problem
Posted: 19 Jan 2026 17:54
by exxos
zfrenchy wrote: 19 Jan 2026 17:21
the original on board is a F.
:thumbup:
Is it snowing now ?
:lol:
Mystery...
zfrenchy wrote: 19 Jan 2026 17:30
OK OK, I know you said before, but my TOS switch is a fail, I put a jumper, and now TOS 2.06 is working.
WAIIA !!! (what an idiot I am)
Oops :)
I wonder if that's part of the 32mhz issue then ? Best to use jumpers and not tie into the booster speed control for diagnostics..
Re: Booster V4sm problem
Posted: 19 Jan 2026 19:36
by zfrenchy
I replaced the 74F257, will see.
But, before I re-solder the 32Mhz wire, should be this wire on pin 3, NOT 4 ?
Screen Shot 01-19-26 at 11.31 AM.PNG
Re: Booster V4sm problem
Posted: 19 Jan 2026 19:45
by exxos
Pin4 is buffered output.. so its correct.
Re: Booster V4sm problem
Posted: 19 Jan 2026 23:53
by HigashiJun
Just remember an issue I had with the booster on one of my STE motherboards:
While the thin wire provided in the kit was OK for the 32MHz signal in two of my motherboards, one motherbaord had however issues with it.
When I swapped the thin wire for a normal Dupont one, the booster started working without any glitches.
Re: Booster V4sm problem
Posted: 20 Jan 2026 01:06
by exxos
HigashiJun wrote: 19 Jan 2026 23:53
Just remember an issue I had with the booster on one of my STE motherboards:
While the thin wire provided in the kit was OK for the 32MHz signal in two of my motherboards, one motherbaord had however issues with it.
When I swapped the thin wire for a normal Dupont one, the booster started working without any glitches.
Wasn't aware of that, at least what I remember..
The wire gives some small resistance, but looking at the scope images, even after the 68R there's hardly any difference.. So I don't really understand why a different wire would be any different..
A 68R in series with the wire on U405 might be worth trying..
Re: Booster V4sm problem
Posted: 20 Jan 2026 01:26
by HigashiJun
exxos wrote: 20 Jan 2026 01:06
So I don't really understand why a different wire would be any different..
Me either... And only one motherboard was concerned.
Re: Booster V4sm problem
Posted: 20 Jan 2026 01:36
by exxos
HigashiJun wrote: 20 Jan 2026 01:26
Me either... And only one motherboard was concerned.
Next time I have mine connected I'll takes some measurements to see if can see any difference..
Re: Booster V4sm problem
Posted: 20 Jan 2026 16:16
by exxos
YELLOW = U405 end
BLUE = STE BOOSTER END
Thin black wire end to end.
IMG_4462.JPG
Thin black wire end to GAL pin1 (68R series)
IMG_4463.JPG
Wire end to end.
IMG_4465.JPG
wire end to GAL pin1 (68R series)
IMG_4466.JPG
So not much of a difference.. But I remember now other wires were causing the "1712 shifter bug"...