Re: REV 3 - The beginning
Posted: 02 Apr 2021 21:02
@JezC yes it dud fit in a 144 originally but I believe the ide int fix needed more than the 144 at the time
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No ground plane on this revision. Pencilled in for rev4. 5 caps, 4 100n, 1u. That ought to be ok, I think.exxos wrote: 02 Apr 2021 19:11 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:
Cool bananas! Well, apart from the bloody CPLD, obvs. :lol:Yep! :)Badwolf wrote: 02 Apr 2021 18:54 That's cured the locking up during VDI draw without cache, you mean?
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...
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.JezC wrote: 02 Apr 2021 20:55 @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:)
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!Badwolf wrote: 02 Apr 2021 21:02 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).
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 wrote: 02 Apr 2021 21:26 If we can ultimately get the floppy to work with a TF536 on an H4/H5 board & EmuTOS then that will be big progress!
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 wrote: 02 Apr 2021 21:35Floppy 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 wrote: 02 Apr 2021 21:26 If we can ultimately get the floppy to work with a TF536 on an H4/H5 board & EmuTOS then that will be big progress!
Was you running MAPROM ?JezC wrote: 02 Apr 2021 21:44 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!