exxos's Atari, Amiga & retro forum

PhilC wrote: 31 May 2020 19:08 @rubber_jonnie thanks for sharing the tos files, you've beat me to it so I shall borrow yours instead of making my own :D

No worries, glad you can make use of them. They're a lot easier to make when they're both 256kb in size, no padding between images needed.

Must get some OTP ROMS though, I'm clean out.

Well, just in time for New Year, I was putting the PSU back in my Mega 4 and guess what?

It died again.

I reassembled it, booted, set the clock, glanced away and then it was dead, nothing on screen. This is becoming a bit of a pain in the ass after working so well for so long!!!

Then, just to add insult to injury, I tried to hook it up to my workbench PC, and the serial port has stopped working on it!!!

Back to the drawing board I guess.

Grrrrrrr

Woo Hoo!!

So first things first, the serial port problem on my workbench PC is fixed, seems some settings were set to default at the last BIOS update, disabling the serial port for anything but serial setup, so that's all good.

Which leads me nicely to the Mega4, which I was able to hook up using serial and the diag cart which showed me an I6 error at start up at the point the timing checks are done.

Immediately my mind went to GLUE, so I swapped that out and lo and behold, we're back up and running again.

2 machines sorted before 11:00 on NYD, and all while still in my pants :)

Just the RAM to sort on the other Mega now.

As a side note, is anybody noticing that more GLUE chips seem to die than anything else?

Ironically, I don't think I have really seen many chips fail. Though its possible GLUE could fail as its feeding V&H sync direct to the RGB port , so its possible as it has "external" connections, its easier for people to kill them... just like.. lets say, the DMA chip... :lol: :twisted:

exxos wrote: 01 Jan 2021 13:21 Ironically, I don't think I have really seen many chips fail. Though its possible GLUE could fail as its feeding V&H sync direct to the RGB port , so its possible as it has "external" connections, its easier for people to kill them... just like.. lets say, the DMA chip... :lol: :twisted:

It was weird, just connected via a VGA switcher to my NEC 1990Fxp, and the screen just went black, and via serial it was failing at the diag cart timing test at boot up.

TBH I haven't tested the GLUE in anything else yet, but I've had about 4 GLUEs die versus 1 DMA and 1 CPU. Nothing else has died on me yet, so for me at least it its proving to be my worst enemy :)

Nice quick fix at least :)

I think it really doesn't help with 30+ year old sockets in the mix :( For a chip to actually fail be pretty rare in my book, but this does not mean they cannot be easily blown up with bad connections etc. but generally they seem to be quite robust chips.

exxos wrote: 01 Jan 2021 15:37 I think it really doesn't help with 30+ year old sockets in the mix :( For a chip to actually fail be pretty rare in my book, but this does not mean they cannot be easily blown up with bad connections etc. but generally they seem to be quite robust chips.

Well, when I consider that he GLUE in the Mega 4 was original AFAIK, and then add in the state of the machine when I got it, which was pretty beat up, in all honesty I mustn't grumble. I have 3 Megas, the MSTE, 2 STEs, 6 or 7 STF/Ms and an original ST, to have them ALL working after all this time is something in itself, especially with Atari's cost cutting attitude.

Funnily enough, the 520ST also had a bad GLUE, and that stopped the floppy from working.

And as for the sockets, I quite agree, they are a big part of the problem too.