Stuff and Things.

[rubber_jonnie]

I can totally understand @PaulJ , sockets have caused me such a lot of grief but in reality, it's almost a case of can't live with them, can't live without them.

Aye, Sockets. Damned if you do, Desoldering if you don't.............

[exxos]

Aye, Sockets. Damned if you do, Desoldering if you don't.............

:lolbig: :bravo: :girldance:

[rubber_jonnie]

Aye, Sockets. Damned if you do, Desoldering if you don't.............

:lolbig: :bravo: :girldance:

I aim to please :)
:girldance:

[rubber_jonnie]

Ok, so the test board had a dodgy floppy power lead, connections going into the mobo were freyed, so that's fixed, and the crappy floppy cable has been removed and theres a nice socket in it's place. Still no joy with known working FDDs.

Hooked up the external drive too,that does the same and diag cart tests fail for both, so I'm feeling like it's a dead WDC1772, so will rip it out, fit a socket and try a replacement as I have several.

One thing at a time, ho hum.....

[PaulJ]

Don't know RJ, maybe "4" is your lucky number. You did persevere and get it all running. :shrug: :shrug:

@PaulJ And I even enjoyed it!! The sense of acheivement at the end was great :)

Whats not to enjoy RJ... its when you never get it running that it sucks. :sigh:

[rubber_jonnie]

@PaulJ Quite, a bit like my ALPHA edition....

Maybe one day :)

[rubber_jonnie]

Hmm, so I still have the same floppy problem with my test board, even after replacing the data cable with a socket fixing the power lead and socketing the WD1772.

The WD1772 tests just fine on the remake board too, and I get the same problem with a spare 1772.

Problem is elsewhere it would seem. Boots up, floppy starts to seek, busy light stays on and the machine never reaches desktop. Time to look at the schematic I think. Also I think the DMA is going in a socket and will be tested in the H4.

GLUE, MMU CPU have all been swapped out but the problem remains. If it carries on like this it'll become my next donor board!!

[rubber_jonnie]

So, I know my WD1772 works, it's been tested and is good.

Cable is good, also tested on the H4, as is the floppy drive itself and power good as the same re-capped SR98 is also driving the H4. I have to assume for now that the socket I retrofitted is good (I will buzz it out, just not right now), so looking at the STFM schematic, there can't be too many things left.

I make it the DMA, the 74LS06 or the Pull up/down resistors on some of the lines.

74LS06 looks easy to switch out, so will have a look at that next, then the resistors and finally the DMA. The desolder gun is a definite bonus here.

[exxos]

I've not read all the posts, but have you added the 1772 pull ups and DMA pullups like the H4 has ? Also the YM chip does drive selections I think.

[rubber_jonnie]

I've not read all the posts, but have you added the 1772 pull ups and DMA pullups like the H4 has ? Also the YM chip does drive selections I think.

No, but it was working fine until very recently without them. I will be doing those though, especially as I also want to replace all of the other pullups too.

It looks like the YM does drive selection and side selection, so that is also a possibility. the LS06 is quick and easy to swap though, 5 minute job. Bit longer for the DMA and YM, plus I need to source some spare sockets before I do them.