exxos's H5 C1 build

[DoG]

It's a 16Mb card and H5 can only use 4Mb so there is probably more of those chips not in use.

[exxos]

It's a 16Mb card and H5 can only use 4Mb so there is probably more of those chips not in use.

Nope. Every chip has part of the data bus going to it :)

[DoG]

Nope. Every chip has part of the data bus going to it :)

:D :?

Chip on bottom side? ;)

[exxos]

Chip on bottom side? ;)

Nope :) this was explained in my blog I think :lol:

[sporniket]

FLASHY CLOCK HEADERS

On my H5, I didn't noticed this jumper at first used a regular DIP-64 socket. For now I will just bridge the two holes in the middle as instructed. If I ever buy a flashy clock, will I need to unsolder the socket and use pin strips as you did ?

[exxos]

On my H5, I didn't noticed this jumper at first used a regular DIP-64 socket. For now I will just bridge the two holes in the middle as instructed. If I ever buy a flashy clock, will I need to unsolder the socket and use pin strips as you did ?

Not necessarily, the problem with the socket is the plastic pushes the four pin head at a slight angle which makes it difficult to insert flashy..Worst case is just file a bit off the four pin headers... I think in one of my boards I just remove the plastic altogether..

[sporniket]

I see, thanks :)

[exxos]

Got 1.44 floppy GAL fitted and working. I will try and add some of these chips to my store next week.

IMG_6647.JPG

I also calibrated GB6 for the H5C1. I will add this benchmark file to future releases of GB6.

IMG_6648.JPG

[StealthGunner385]

Got 1.44 floppy GAL fitted and working. I will try and add some of these chips to my store next week.

Looking forward to adding those to the cart as well.

[exxos]

So this is odd... I have Steve's rev A3 here where the 3.3v outputs about 3.60v. But when the reset button is pressed, the voltage drops to 3.3v . I was thinking as part of the reset line is pulled to 3.3v, something could be pulling it higher like the reset chip as it's running on 5v.. But as the chip needs a pullup it doesn't make sense. The only other chip is the input to the reset buffer IC as it runs on 5v. TTL tend to float high, but IIRC the reset line is pulled up by 10k, so it would also seem unlikely. But nothing else is connected to reset.

On the latest C1 board, the voltage stays at 3.60v on the regulator regardless of reset being pressed. Even so it's odd what is causing this higher voltage on the 3.3v regulator.

So can others confirm the voltage is 3.60v instead of 3.30v? I guess it would be useful to remove the reg and test to make sure they are not just really bad tolerance, but the tab I think is 3.3v so not so simple to just lift a leg and try it :roll:

I'm not sure what protection the regulator has, but if something is pulling the 3.3v to higher voltages, then I would really expect it to blow the regulator up. But it hasn't done in any builds so far that I'm aware of.

It's a bit of a odd unexpected issue. I guess the regulator should have a small load on it to keep the voltage at the proper level of 3.3v. I would assume 1k would be enough to load it.