exxos's Atari, Amiga & retro forum

PaulJ wrote: 04 May 2020 20:33 If you use 2 ST's transmit and recieve are on the same pins so you need to make sure pin 2 & 3 get swapped on one end so t->r and r->t. Try a cable on known good st's to make sure cable works. I'm sure you know but sometimes one just assumes the cable is right. :)

@PaulJ Thanks for the reminder - I've had the cable working between the same PC & a different ST via GhostLink (and a Falcon without the 9<->25 way adaptor) so it should be ok.

I will try it on the laptop & if I'm still having trouble, I will put the DiagROMs in a working ST & check what they do.

It almost always seems that it's setting up the system to test that takes more time than the testing & diagnosing...but we will see if I can prove myself wrong with this!

If it doesn't just work with the laptop I will have to leave it until tomorrow evening/night :roll:

DoG wrote: 04 May 2020 20:05 Yeah. Test a diag cart in a working Atari and hook it up to another Atari, Amiga, PC with a com program with 9600,8,N,1 to see how it all works.

I use a USB to COM from a Win10 laptop hooking up to a broken Atari. Can't remember what com program I use though.

@DoG If you do remember which you use on the Atari I'd be interested to know (then I can do the diagnosing where there is more space - further from my PC/work Laptop etc. but in the meantime I will persevere with the cramped ST repair/PC zone...

PhilC wrote: 04 May 2020 17:36Its 9600 8 N 1

@JezC what @PhilC said :)

JezC wrote: 04 May 2020 22:19

DoG wrote: 04 May 2020 20:05 Yeah. Test a diag cart in a working Atari and hook it up to another Atari, Amiga, PC with a com program with 9600,8,N,1 to see how it all works.

I use a USB to COM from a Win10 laptop hooking up to a broken Atari. Can't remember what com program I use though.

@DoG If you do remember which you use on the Atari I'd be interested to know (then I can do the diagnosing where there is more space - further from my PC/work Laptop etc. but in the meantime I will persevere with the cramped ST repair/PC zone...

On Atari I used ANSITERM.

DoG wrote: 04 May 2020 23:06 On Atari I used ANSITERM.

@DoG Ok, thanks - I will keep an eye out for that for later.

Meanwhile I managed to prove that the cable & Teraterm & DigROM were all working OK in a booting STFM with the old Win XP laptop - :yay:

So, encouraged by that success I put the ROMs in a non-booting STFM & powered up - nothing useful on the monitor but a whole load of output on the serial port into Teraterm!
Quite a lot of RAM fault output to decypher but I could at least see some of it was working :D
This particular ST appears to be a 520 that someone has tried to upgrade to a 1040 by populating the other 16 RAM sites...but I don't yet know if that is the problem or incidental.

I have another non-booting STFM (this one is still a plain 520) to try in a little while (ok., tomorrow given my usual rate of progress :roll: ) but I'm starting to hope that I have found a true contender for at least one donor system (for shifter, glue, MMU at least as they are socketed, possibly DMA & a few others if I can desolder them safely).
:thumbup:

So, I'm creeping ever closer to having all the parts to finish off the first H4 & making good inroads towards the second as well.

Oh, and I managed to win something on the premium bonds as well - :shock: - so that must make today a good day!

@JezC Got any pics of that serial output showing the RAM errors?

rubber_jonnie wrote: 05 May 2020 23:08 @JezC Got any pics of that serial output showing the RAM errors?

@rubber_jonnie No, but I did copy the Teraterm output into a notepad file...I just need to copy it off the laptop & post it in here/analyse it on a PC with a bigger screen (and a proper mouse rather than a trackpad).

Hoping to get chance to do that late afternoon/early evening today.

It did look like the first address ($400)was reading back as all 0xFFFF if I remember correctly (but there were a huge number of diagnostic output messages so I suspect it's not a single simple fault).

I also have another ST with a similar/worse memory fault (no memory upgrade) to have a go at then also.

@JezC I'd be really interested to see the error messages, I'd like to try and put together something on troubleshooting with a diag cartridge, and in particular a dead machine, so any screenshots and other detail would be good.

@rubber_jonnie Ok, will add it as an attachment.

Though I don't have it as a cart, I programmed up the pair of 27C512 EPROMs you sent me (thanks again for that) with the DiagROM from TF's GitHub repository & used them in place of the TOS ROMs.

If it's anywhere near as good as your Gotek guide, I'm sure it will be very useful!

Will make sure to post it at some point later today.

EDIT - During a particularly long recompile on the laptop, I multi-tasked & copied the log off the laptop & have attached it here... @rubber_jonnie Hope the above is some use for you!
When I get chance to run it on the other board, I'll post any debug output I can get for that one too.

@JezC Thanks, I will take a look!