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Re: Falcon FPU - who can help?
Posted: 30 Jan 2022 11:27
by exxos
mgi wrote: 30 Jan 2022 09:15
Based on this I may pass on removal if it means resoldering the CPU legs back and I may look for somebody who actually knows a bit more. I really don't want to mess up this Falc
This is why I requested images to see what's been done... It may be as easy as it looks to remove...
Re: Falcon FPU - who can help?
Posted: 30 Jan 2022 12:32
by mgi
I will have a look and take some pictures
Re: Falcon FPU - who can help?
Posted: 16 Feb 2022 12:23
by mgi
Hi,
I had a deep dive into my Falcon and found a monster :)
Please have a look. Clearly the CPU leg was unsoldered and lifted up. I really would like to find someone who could get the Falcon to the stock status with the usual fixes and caps changes.
4939D5FA-79B4-4901-8B69-56261903E3B3.jpeg
CF3FB49E-E980-4C3F-9604-99C18A53E761.jpeg
B0A1DA5C-63FC-436D-936D-CC0BDC6EE4E8.jpeg
Re: Falcon FPU - who can help?
Posted: 16 Feb 2022 12:36
by exxos
So that wire is soldered onto the cpu leg ? Its likely that will snap off when bent back :( I guess remove everything and finding a SMT rework company that can change the CPU for starters.
Re: Falcon FPU - who can help?
Posted: 16 Feb 2022 12:46
by mgi
Yes, the wire is soldered to the leg.
Do you know any company who could do this or somebody who could pick up the challenge?
I would prefer to hand it to somebody who knows how to fix Falcons ideally....
Re: Falcon FPU - who can help?
Posted: 16 Feb 2022 12:51
by Steve
Seems it is normal that the FPU does not work with this card:
https://www.atari-forum.com/viewtopic.p ... 26#p285270
by Omikronman ยป Sun Dec 20, 2015 11:05 pm
Beware of that bad Eagle Sonic. I had one. In 32 Mhz mode die FPU worked but the DSP not. In 16 Mhz mode the DSP worked but the FPU not. Speed increase was not worth the price anyway. :(
Sorry I'm not doing work on machines anymore though.
Re: Falcon FPU - who can help?
Posted: 16 Feb 2022 13:49
by exxos
mgi wrote: 16 Feb 2022 12:46
Do you know any company who could do this or somebody who could pick up the challenge?
I would prefer to hand it to somebody who knows how to fix Falcons ideally....
It depends where you are in the world. But I assume you could remove the wires yourself then find a local SMT rework company to change the CPU. Then pass it over to someone who knows how to do the general mods.
I don't know anyone who does mods anymore. While I could do it, I have several months backlog of work to get through yet. So wouldn't likely be even this year.
Re: Falcon FPU - who can help?
Posted: 16 Feb 2022 15:06
by Badwolf
Those two pins are BG (the raised isolated one) and BGK (the one with the wire to, I presume, ground).
The former stops the processor issuing bus grant permissions to anything else on the system. The latter, by being grounded, holds the processor in high impedence state.
If you don't wish to risk bending the legs back and possibly snapping them off, then you could instead remove the extant fly wire and (maybe choosing a finer wire guage this time!) solder wires on the both of these and route them to pin 4 on the nearby GAL U68 (BG) and pin 2 on the same U68 chip (BGK).
BW