REV 3 - REV 5 - The beginning (ST536)

[PhilC]

@JezC yes it dud fit in a 144 originally but I believe the ide int fix needed more than the 144 at the time

[Badwolf]

Assuming you are using a ground plane and enough decoupling caps ? Also some of these chips tend to blow up if you have a bad power connection on one of the pins as well :roll:

No ground plane on this revision. Pencilled in for rev4. 5 caps, 4 100n, 1u. That ought to be ok, I think.

I think, to be honest, my expansion connector is under the weather. It's seen more cycles than it was likely meant to. Might have to pop the board out and reflow the back side of the pins. I wonder if power didn't make a good connection and it got a load of 5V lines up its clacker. There are five power pins across two connectors, so seems unlikely, but it's getting tiresome (and expensive).

That's cured the locking up during VDI draw without cache, you mean?

Yep! :)

Now I am trying to work out why the board only works with a fan blowing on it :lol: :roll: So far with the help of freezer spray, it looks like it's the PLD itself :roll: though I have been contemplating moving down to the 144xl As they offer high-speed grades...

Cool bananas! Well, apart from the bloody CPLD, obvs. :lol:

BW

[exxos]

@PhilC Didn't the original TF536 stuff fit in a 144 for the ST?
There was some mention of keeping the 288 in case there was a "man in the middle" fix for something (possibly IDE with TOS? :shrug:)

There was some code for the IDE to not need the IRQ wire.. but im not really planning on porting that currently.. I doubt that would fit in the 144.

[exxos]

No ground plane on this revision. Pencilled in for rev4. 5 caps, 4 100n, 1u. That ought to be ok, I think.

I think, to be honest, my expansion connector is under the weather. It's seen more cycles than it was likely meant to. Might have to pop the board out and reflow the back side of the pins. I wonder if power didn't make a good connection and it got a load of 5V lines up its clacker. There are five power pins across two connectors, so seems unlikely, but it's getting tiresome (and expensive).

Even when I was doing my 16MHz stuff, between CPU pins I could have a 1 V drop just across like 1 cm of track!

Check out march 10th 2015..

https://www.exxosforum.co.uk/atari/last/16mhz/index.htm

But yeah, all this stuff does get incredibly expensive. I had to junk the first batch of 30 of the TF536 as there was a short on the internal layer... The second batch of 30 I managed to mess up the IDE connector... Cost do quickly ramp up which is why I have to offload some of my stuff to store sales but anyway won't go into a rant about that again....

[JezC]

@exxos @PhilC Thanks - glad to know the old grey cells are retaining at least some of the info in my old age... ;)

I'm not overly worried about having to run a wire for the interrupt with IDE...as IIRC EmuTOS worked O without it anyway?

If we can ultimately get the floppy to work with a TF536 on an H4/H5 board & EmuTOS then that will be big progress!

I need to find a way to make some time for my retro projects...that's been sadly lacking thus far in 2021 :cry:

[exxos]

If we can ultimately get the floppy to work with a TF536 on an H4/H5 board & EmuTOS then that will be big progress!

Floppy works fine on the H4 and TOS206, its MAPROM which causes the problem.. its why I hacked it earlier to get it to behave. Assume EMUTOS will work but not tried it.

[JezC]

If we can ultimately get the floppy to work with a TF536 on an H4/H5 board & EmuTOS then that will be big progress!

Floppy works fine on the H4 and TOS206, its MAPROM which causes the problem.. its why I hacked it earlier to get it to behave. Assume EMUTOS will work but not tried it.

Ok, thanks fro the info. I will have to flash an EPROM with TOS2.06 & try that with the T536...only tried EmuTOS up 'til now...and with the older 0.9 the floppy worked after EmuTOS booted from floppy but with 1.0 it booted from floppy but then wouldn't access files on the floppy...so I gave up!

[exxos]

Ok, thanks fro the info. I will have to flash an EPROM with TOS2.06 & try that with the T536...only tried EmuTOS up 'til now...and with the older 0.9 the floppy worked after EmuTOS booted from floppy but with 1.0 it booted from floppy but then wouldn't access files on the floppy...so I gave up!

Was you running MAPROM ?

[JezC]

Not with EmuTOS 1.0...with the floppy not working after starting EmuTOS, I had no way to load any programs.

Can't remember with 0.9 (but the floppy worked OK then).

I might have already programmed an EPROM with RJs 512k image with a modified TOS 1.04 with IDE support & 2.06...now the question is can I find it...?

[exxos]

Been doing some more testing, I think it is the CPU acting up not the PLD... It does not really feel that warm either but it does not work without a small fan blowing on it all the time...

Saying that, only seems act up when TOS is loaded into TTRAM...It will load GB6 and run just fine with no TTRAM... YAARTTT ( at the time of typing) is not reported any TT RAM errors in testing either...

EDIT:

OK so it just died on TTRAM test... It just locks up solid.. Maybe 32bit is more problematic on overclocks :shrug: