[Video] A simple A<-->B drive switch mod

[Badwolf]

Happy weekend!

Having had a few Bad Jobs recently, I decided to do some work on my 'practice' STFM board and wasn't planning to record it, but having had a bit of success socketing and replacing my YM chip and fitting a floppy connector (instead of the hard-wired cable), I thought I'd document my drive A and B (internal and external) switch mod.

Very simple on my -FM revision and works a treat to let me boot an external Gotek as drive A.

Take a nose here:



Cheers,

BW

[chronicthehedgehog]

Watched that earlier - nice tidy mod. Is it the same on the STe?

[Badwolf]

Thanks. I think the STE will probably have to have an interposer on the YM chip as I think the select 0 line is wired direct through (I can't see any links on the way to the internal connector).

BW

[coonsgm]

Nice job with a clean, quick description on how to make this mod. I think the comment "tidy" sums it up.

[krupkaj]

Watched that earlier - nice tidy mod. Is it the same on the STe?

There are jumpers W300 and W301 at the STE motherboard.

[Badwolf]

Watched that earlier - nice tidy mod. Is it the same on the STe?

There are jumpers W300 and W301 at the STE motherboard.

Do either break the connection to the internal floppy port, though? It doesn't look like it on the schematic.

BW

[danboid]

Thanks for this great video BW! I'm going to have a go at this on my STFM later.

As for the STe, there is this thread where people claim to have done a similar hack. I had quick go at this on my STe without success. A video would be nice if you get it working BW:

https://www.atari-forum.com/viewtopic.php?t=32863

[danboid]

I'm feeling terrible today but I'm hoping that if I publicly confess what I did it might somehow make me feel better. Unlikely but here we go. I'm pretty sure I've killed my STFM with a heat gun yesterday trying to pull this mod off. Literally one of the worst moves I ever made. I've not turned it on yet to verify the damage but I suspect that if it does still turn on then the floppy drive isn't going to work, at least. I'm still trying to come to terms with what I did.

I tried removing L39 with a solder sucker first and when that didn't work I thought I'd put kaptan tape around the surrounding area and get it out with a heat gun. I did get it out but I've also burnt through the solder mask around L39 and I can see I've damaged a few tracks. Now I feel like I've killed a child or a pet or something.

This was my first time experimenting with kaptan tape and most of that melted away before the link came out. I did manage to remove L39 but at what cost? I had successfully used the same heat gun without the use of the tape to remove various Uzebox components from failed builds recently without damaging their PCBs but it seems that the modern PCBway PCBs can withstand much more heat than these olde ST PCBs.

Thankfully I've still got my STe, which is never going under the heat gun. I'll probably keep my STFM for spares. I'll have to buy a proper desoldering gun before I ever attempt to desolder anything myself from my retro computers. What do people recommend?

Let this be a warning to anyone else thinking of modding their working computers without proper tooling!

[Badwolf]

Oh dear!

Is this a temperature regulated hot air desoldering station or like a paintstripper?

You may be able to salvage things as the traces aren't too dense around there and you can probably bodge your way out of trouble.

OTOH it could be a good excuse to get an H5 remake motherboard as you've now got all the chips handy!

BW

PS. We've all been there with hot air. See the mess I'd made of this Amiga expansion trying to hot-air remove some corroded chips ->

[danboid]

Here is what I done did. I've not dared turn it on since the abuse. What says ye Mr Wolf?

brutalised-board.jpg (315.33 KiB) Viewed 76 times

Here's the implement of the destruction:

Exhibit-A.jpg (204.34 KiB) Viewed 76 times

It would be good f someone could recommend a known good desoldering gun / station from AliExpress as they seem to be quite pricey from Amazon etc which is why I haven't invested in one until now but this has been the best motivation yet. I now know I got lucky with my previous usage of this heat gun.

I think the H5 is very cool and I'm glad that it exists although I don't think I can quite justify the price tag. I'd gladly pay £150+, probably up to about £300, for a Falcon reproduction board if I could source all the chips (yeah right) but I could probably get at least a couple of second hand ST(FM)s for the price of the H5. My STFM only cost me £50 thankfully but annoyingly it was in good condition before I violated it last night.