Bikerbob's H5 C1 build

[Bikerbob]

The drawing shows the traces on the board, that's why I did it the way I did as I'd already soldered a header in place.

But yes you can do it either of those 2 ways.

OK, so I took my wire links.. and I combined 1&2 and fed it to pin 4 on the small pin group.

So the floppy noise and any of the screen feedback issues seem to be gone, but there is still the constant white noise in the background which modulates with anything being done, i.e. keyboard, HDD access or floppy access - but is now just a modulation of the white noise.

This can be heard with the volume at what I would call listening level - about 1/4 of its total volume.

I have still got all my STORM/CLOUDY and LIGHTNING on the board.. so I am going to remove that.. go back to just the CPU.. and I think put the exxos dual tos and decoder on.. I don't remember this noise when I first powered up the machine.

James

[Bikerbob]

Here is something interesting I noticed..

Pushing the mouse button Silences the white noise while I have it pressed.. when I let go.. the noise returns?

Now the GLUE is a PLCC .. so the socket would have already been in.. Timing testing on Diag cart shows nothing off.. I guess I will check solder points, and then pop it out and reseat it?

James

[Bikerbob]

OK, new development.

It is quiet now.. with all my addons in etc..

What did I do? - reseated the GLUE.. Now the GLUE I have is an IMP.. It does not fit the socket VERY TIGHT.. it does snap in.. BUT I find it very easy to pop out with a PLCC remover.. much easier than I have come to expect.

When I first restarted.. it was quiet.. I ended up having to move the board a bit.. and next boot was noisy again.. Changed the PSU to another I have.. that I had not tried in the machine yet.. QUIET.. so rebooted did some stuff.. then decided to add back the addons.. noisy..

Seems as long as I don't "flex" the board, or move things around too much it is quiet now.. I have tried with addons out. addons in.. 3 different psu.. and if I am VERY careful, they are all quiet... SO I am thinking I might not be getting the best contact on the socket.

I am going to assume there is no easy way to make the socket fit tighter??

James

[exxos]

Some good progress there!

The sockets should be tight anyway, they are 3M which are the best ones I have found. I have found some CPU's not fit sockets tight in the 100's i've tested. I have never seen that with a different chip yet though. So I am not sure what's going on there. A couple of my remake boards have IMP chips and not had any issues. Might be better swapping it out of another machine. Original machines normally have those metal clamps to keep things solid. So finding a better fitting chip might just be the best solution.

[Bikerbob]

Some updates.. sigh.

I have not tried to switch out the GLUE yet.. I assume that those retaining clips would not help.. would not fit the new socket?

Here is my bigger issue.. and yes it is for me because I use floppies.

For some reason and I cannot for the life of me figure out what I changed or what happened. I cannot write to a floppy. Any floppy.. SD/HD

Reading.. np.. all floppies. It starts the process and then says floppy might be damaged.

I have 2 sony 920s and it is doing it on both.

Kobold or TOS no writing.. Kobold cannot format - BUT TOS CAN???????? but even a new fresh formated disk.. will not write to.

OMG this is frustrating.

James

[exxos]

I don't think the clips fit moderns sockets. Floppy malfunctions can easily be the GLUE as it controls DMA cycles and enable signals for a lot of the system like YM chip. One trick I do is to just lift the chip like 1mm higher with a small square or 2 of card etc. It generally helps bad contacting chips.

Also check the GLUE doesn't have any bent inwards pins or skewed pins on the corners in particular. Of course reseat and clean chips with IPA, DMA, GLUE,MMU,YM,DMA etc.

FCOPYIII is a good tool for testing reading and writing to floppies. I only use real floppy drives personally.

Also, have you tried a normal flat ribbon cable for the floppy ?

[Bikerbob]

I don't think the clips fit moderns sockets. Floppy malfunctions can easily be the GLUE as it controls DMA cycles and enable signals for a lot of the system like YM chip. One trick I do is to just lift the chip like 1mm higher with a small square or 2 of card etc. It generally helps bad contacting chips.

Also check the GLUE doesn't have any bent inwards pins or skewed pins on the corners in particular. Of course reseat and clean chips with IPA, DMA, GLUE,MMU,YM,DMA etc.

FCOPYIII is a good tool for testing reading and writing to floppies. I only use real floppy drives personally.

Also, have you tried a normal flat ribbon cable for the floppy ?

OK, all sounds good.. will do.. I can try another floppy cable.. hopefully I have one around.. I'll dig.

Here are a few more pics and a link to the video.. The machine is Polling?? or looking at the floppy all the time? is that normal?



James

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20220212_110551.jpg (327.43 KiB) Viewed 3091 times

20220211_182416.jpg (198.61 KiB) Viewed 3091 times

[exxos]

The drive does poll about 4 times a second. It's just not always visible on the LEDs.

As for soldering pin2 on the drive, your doing something out of the norm and I've not tried it to see if there are any issues. So you're kinda on your own with that mod.

[Bikerbob]

OK so otherwise.. run a longer wire to the pin on JP18.. with the * correct?

[exxos]

OK so otherwise.. run a longer wire to the pin on JP18.. with the * correct?

Yep. But IMO remove the wire from the drive and just jumper JP18, JP19 and get 720k working first.