REV 3 - REV 5 - The beginning (ST536)

[exxos]

@Miri

If your mega doesn't have a blitter, I assume you have the solder pads linked on the mb?

The TTram controller hasn't changed since original TF536.. But I did find I had to invert the clock on the original ST536... we could try that but otherwise I can't replicate the issue on my H4 setup.

[exxos]

Thanks, the stuff has arrived. I'll prepare the computers over the next couple of days and will give it a test.

Probably be useful if you can try a mega ST and see if your stable will or not..

[PhilC]

Thanks, the stuff has arrived. I'll prepare the computers over the next couple of days and will give it a test.

Probably be useful if you can try a mega ST and see if your stable will or not..

Ok, I need to put a CPU socket in the Mega 2, so will try do that tomorrow. I'll leave the ram upgrade till after.

[exxos]

I've uploaded CURRENT21 firmware just. Reason for this is I seem to have mixed some stuff up while doing ST and STE firmware then merging them into 1

CURRENT21.. Normal version is without inverted SDRAM clock ( as per original TF536 code).
CURRENT21I.. Inverted SDRAM clock ( as per original ST536 code).

Most likely CURRENT20 was inverted clock, which was what worked stable on the original ST536,

I don't recall there being any issues with either clock on the STE536.. But its not had much testing on the ST536 yet.. So one clock phase may work better than another.. Or it may not matter at all.. But that's the only issue I found with the TTram controller.

@Miri you may be best trying both 21 versions to see if anything changes.

Though it's odd you can copy ROM to TTram on TOS206 start just fine, but then locks up on TTram test..

I will try and find some time tomorrow to test both in a STE536 to see if there's any difference...

[PhilC]

@exxos Jus fitted the socket and new ram to the Mega 2 and have the ST536 booting to Emutos 1.4 with the firmware that you'd installed on the ST536 that you'd sent me. It'll run Gembench and frontier, does crash occasionally.

It's not totally happy with ST536 tos, it will do the rom copy, then the memory check but keeps resetting whilst testing ST ram. I've once got to desktop with it once but its doesn't recognise the BBAN.

FYI, I've replaced the oscillator on this Mega but since I've just got this Mega, haven't done the bust pull-ups yet. It has its blitter fitted.

On the Mega ST4 that runs my original ST536 just fine it will run Emutos but crashes as the other one does. St536 tos it gets to the memory check, resets whilst doing the memory check, resets again, then comes up with bad rom CRC. This Mega ST4 has no blitter, has bus pull-ups changed, an exxos PSU and 4mb ram upgrade(MMU mounted type) This Mega ST also has another cap in parallel to the reset one to give it a longer reset delay.

So it seems to do the same thing or thereabouts on both Mega's. This Mega boots quit happy to the desktop and will run Gembench & Frontier without crashing sing my original 144XL St536.


I need to set my Pi5 up so that it can do Xilinx programming and then I'll give it a go with the new firmware but that might take me a day or two.

So far though, it runs Gembench, albeit slowly as invent set up

[exxos]

Thanks @PhilC Very odd indeed. It ran all day on my H4 here. Do you have a H4 or H5 you can easily test on ? Assume your running BLTFIX as it won't be stable without it and a blitter fitted..

I just tried both firmwares on the STE536 and no odds either way. But one may work better than the other on the ST536.

You may have to lend me your mega to investigate the problem I could do a million different firmware tweaks but I went through all this with @Badwolf for ages and just easier to have the board in front of me to test stuff out.

Don't know why the original ST536 would work but not the updated one, that's even more odd. The original ST536 was unstable to start with

EDIT:

The bus grant stuff was speeded up on later builds, over the original 144 firmware.. so maybe that's an issue on your machine

[PhilC]

@exxos in the meantime I've done the bus resistors on the Mega 2 and have fitted a recapped PSU which makes it more stable but it still refuses to run ST536 Tos, exhibiting the same behaviour.

It all do Gembench on Emutos but crashes when playing frontier, with frontier having screen glitches every second or two.

I am running blitfix on this Mega. I'm presuming you've not enabled IDE yet as I can't get it to boot from there.

FYIon a Mega, you need to either add a spacer on the CPU socket or put something underneath the ST536 as the 030 CPU socket can touch the rom sockets.

I'll try and dig out the H5 and remember where I put all its parts that I stole for other things

[exxos]

It all do Gembench on Emutos but crashes when playing frontier, with frontier having screen glitches every second or two.
it still refuses to run ST536 Tos

Sounds like more like a TTram issue. Though don't see how as I ran TTram test for a few hours before sending it you.

I'm presuming you've not enabled IDE yet as I can't get it to boot from there.

IDE is enabled.. I use it all the time for running stuff from.

FYIon a Mega, you need to either add a spacer on the CPU socket or put something underneath the ST536 as the 030 CPU socket can touch the rom sockets.

good to know.

I'll try and dig out the H5 and remember where I put all its parts that I stoke for other things

I will compile a slower bus grant logic.. then you can try that... I don't know what else has really changed in the core since the 144 stuff.

[exxos]

Sorting out the new BOM..

Can I find the feking + to move or edit the part numbers on the IDE connector!! Either I am going blind or its not there !

ide.PNG (57.66 KiB) Viewed 121 times

When I place a new part, it "snaps" to the center.. but there's nothing there.

When I use the search tools it should put the cross in the center of the screen.. but I just get this...nothing there!

ide2.PNG (63.79 KiB) Viewed 121 times

.. and yes i've click and moved every cross there and nothing hidden away..

Capture.PNG (25.33 KiB) Viewed 118 times

It has the cross on the PCB, just not in the schematic part. So edited the attributes there.. just hope it reflects in the BOM as well..
EDIT
Nope. Will just have to find or create a new lib, one which isn't weird !

[exxos]

So LCSC don't have all the parts in stock. Emailed to ask if they have a ETA. Might have to order some stuff from Mouser which I don't really want to do. Gets very confusing order parts from multiple places all the time

Capture.PNG (172.62 KiB) Viewed 99 times

EDIT:

Well the Oscillators are like half price in Mouser (***), where most things in mouser are like 10x price of LCSC! So looks like I am doing a Mouser order as well now then

(***) I suppose China could be buying them from the USA, so mix in all tarrifs I suppose that's how it happend.