CURRENT PROTOTYPE STATUS (SEC 64MHz 68000)

[exxos]

Same firmware in both?

Mine was the updated version, and seemed to work better than the older one, oddly.

[PhilC]

I can test it at some point, will let you know which fw my two have, one cased, one not.

[exxos]

I can test it at some point, will let you know which fw my two have, one cased, one not.

oh thought you meant the SEC booster :) no idea what firmware in the U.S.

[PhilC]

Might be worth checking?

[exxos]

Might be worth checking?

I dont think its a firmware issue with U.S. It works in 8MHz mode. But these issues I had with the STE booster and never solved. Though U.S. was working on the previous SEC booster, but that was on another motherboard.

[exxos]

I am partly thinking the bus buffers are not fast enough to isolate the CPU causing the conflicts.. But I am not convinced on that idea because the floppy drive worked perfectly fine and that also goes by the DMA chip.

The hard drive and floppy drive even share the same interrupt pin on the MFP,So I don't know why the floppy woodwork and not the hard drive. Nothing in that respect is running at any higher speeds either.

I think as the video is going funny, be that the CPU is trying to access the bus while the buffers are in transition which is basically shorting out the hard drive and video. I have asked @Icky to try some "F" series buffers in his H4 to see if it helps.

It is also possible that because the 8Mhz clock isn't exactly in sync with the GLUE's 2MHz clock, that things could be going out of sync anyway. I may have to route the 2MHz clock to the PLD (more bodge wires) so I can more accurately keep track of when the CPU can access the bus.

EDIT:
Also slightly odd that U.S. Doesn't even have to be turned on to cause issues.
Also tried a MEGAFILE 30 and machine won't even boot, just garbage on screen.
Won't even boot the diagnostic cart with U.S. plugged in (on or off)

EDIT2:
The only thing which may be different between the 1771 & HDD is that the 1772 will be sending into request based on the 8 MHz clock, whereas the hard drive likely doesn't. But even so, going via the MFP, its being clocked at 4MHz ,so would assume it wouldn't matter anyway.

EDIT3:
I double clocked the MFP and no change. Was trying to think if the CPU was processing the interrupt twice for some reason.

[exxos]

I've started a second topic https://www.exxosforum.co.uk/forum/viewt ... =39&t=2459 releating to the ultrasatan issues.

So far, EMUTO & 40MHz OSC seems to mostly behave. TOS206 just seems to give garbage at power up and doesn't boot with ultrasatan plugged in .
I also tried 25Mhz OSC, TOS206 booted and first load of a PRG from U.S. I got 2 bombs, then it loaded fine.

[exxos]

A tiny bit of progress after endless trial and error.. On this current version of the booster, I routed A1 via the PLD to add a small delay because the floppy drive was not working otherwise (I mentioned this ages ago somewhere in this thread). So I added in more delay and now the hard drive behaves at 40MHz in TOS206 ( I say behaves, but this is only some quick tests, as it would not boot up at all before)

So I added in more delays onto A1 and now it would not boot up at all again. Because the only fast requirement for the address bus is currently ROM access, I delayed the ROM speed equally by the amount delayed on A1, and the machine booted up again as before.

Going back to the 50 MHz crystal, machine is trying to boot, but I am back to the original problem that the video is dimming while accessing the hard drive. I think actually this is a second problem which manifests itself at high speeds whereas at lower speeds it doesn't.

So there is actually two problems going on here which I think is why I have not made much progress with this. The first problem that A1 needs to be delayed, presumably something screwy going on with the DMA access somewhere. Secondly, a second problem manifests itself as also hard drive issues, but also causing video problems, which I believe is a separate fault to the previous one.

EDIT:
Even though the hard drive seems to be working reasonably well now, the floppy drive has stopped working totally now :roll:
When ultrasatan is unplugged, the floppy drive starts working again normally.

EDIT2:
Oddly though, when ultrasatan is plugged in, the voltage on the databus drops to 2.5V...

[Elliot]

I have never seen the TOS memcheck indicate an error - so thats what happens......

[exxos]

Who'da man 8-) 8-)

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