Life, the universe & everything...Atari (well, mostly)

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exxos
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Re: Life, the universe & everything...Atari (well, mostly)

Post by exxos »

JezC wrote: Thu May 07, 2020 10:29 pm @rubber_jonnie Ok, thanks for the warning.
I was hoping to work out which address line it was (and whether for row or column address) & use the schematics to trace all the nets on that memory bus...but maybe I should re-think that approach.

Something to ponder overnight. :?
The ST schematic is good quality in the downloads section. https://www.exxosforum.co.uk/forum/viewt ... f=31&t=100
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
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Re: Life, the universe & everything...Atari (well, mostly)

Post by rubber_jonnie »

exxos wrote: Thu May 07, 2020 11:52 pm
JezC wrote: Thu May 07, 2020 10:29 pm @rubber_jonnie Ok, thanks for the warning.
I was hoping to work out which address line it was (and whether for row or column address) & use the schematics to trace all the nets on that memory bus...but maybe I should re-think that approach.

Something to ponder overnight. :?
The ST schematic is good quality in the downloads section. https://www.exxosforum.co.uk/forum/viewt ... f=31&t=100
@exxos That's really much nicer quality than the ones I have! Just had a massive download spree to replace all my terrible ones!
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Re: Life, the universe & everything...Atari (well, mostly)

Post by JezC »

@exxos @rubber_jonnie Ok - I will get those & go back to my original plan for where to start continuity/short checks (though I'd expect an open circuit is more likely rather than a short).

Won't get much time until late evening for diagnosing...other household/gardening tasks have been set as a higher priority. :(
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Re: Life, the universe & everything...Atari (well, mostly)

Post by rubber_jonnie »

JezC wrote: Fri May 08, 2020 10:44 am @exxos @rubber_jonnie Ok - I will get those & go back to my original plan for where to start continuity/short checks (though I'd expect an open circuit is more likely rather than a short).

Won't get much time until late evening for diagnosing...other household/gardening tasks have been set as a higher priority. :(
Bear in mind you may have problems between RAM chips/sockets as I did.

Annoying that I upgraded that board, found a problem with A7 in the new bank, then the floppy interface died! More donor parts for H4s though!
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Re: Life, the universe & everything...Atari (well, mostly)

Post by JezC »

As usual, all my plans are for nought...still no nearer diagnosing the faults on those two boards, alas.

However, I did manage to find some time to program up some 27C256 EPROMs with 6 chip TOS 1.04 images & plug them into a couple of 520 STF motherboards (one had German TOS 1.00, the other appeared to be UK TOS 1.00).

Both boot to desktop & are reported as UK TOS 1.04 by sysinfo.
Long-term plan for these two is to upgrade their RAM (to at least 1024k but possibly to fit some memory expansion boards I have somewhere) & take them up to 2.5 or even 4 Meg!

I've also started to organise the bits for finishing off the first H4 to see what I need to buy or salvage from a donor...
I'm also trying to see what else I need for the two IDE v1.1C boards as well with a view to ordering them once I have some money to spare!
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Re: Life, the universe & everything...Atari (well, mostly)

Post by JezC »

In my usual fashion, I've ended up leaving the further diagnosing of the other few faulty systems for a while & had a quick look at another... :lol:

This is a 1040STF with 2x ROM on a C70789-001 Rev B board.

I started to look at this one because I saw it didn't boot & noticed that the ROMs were fitted in H2 & L2 rather than H0 & L0...so was hoping it was just the ROMs being in the wrong sockets!

As it was, it fails to boot & shows a solid white screen...swapped the ROMs & it still fails to boot but seems to reset itself periodically.
Put in DiagROM & it passes the memory check on the full 1M.

Hmm...will have to leave this here until later this evening... :?
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Re: Life, the universe & everything...Atari (well, mostly)

Post by JezC »

Well, how did all that time pass so quickly? :shrug:

All diagnostics were put on hold by various family dramas for a while...and the little time normally available for retro pursuits has been lost to other things :cry: :ball:

Anyway, managed to snag 3x 'working' STFMs (a mix of 520 & 1040s) for a very good price (@PhilC that's what happens when you tell me to sort out the other bits before I get that TF board off you :-x :shock: ) & have now had chance to check them a bit further.

One 520 seems basically ok - even the floppy worked to run SysInfo.
The other two booted to the desktop but floppies didn't work (still happy enough) so will investigate further when I can, hopefully by next week.

And I'm in the process of finalising the order for the missing components ready for building the Exxos v1.1 IDE boards to get my H4 ready for that first TF536...

I will have to work out how I can get an IDE device (CF card, 2.5" hard drive or even IDE ZIP drive) ready for this board... maybe format it on my Falcon first, then use the demo version of HD Driver and EmuTOS to have a system booting from IDE.

I've still not found my original old HD Driver floppy to get the discount on the upgrade :shrug: but will keep sorting through boxes looking for it (plus some other goodies) under the pretext of sorting 'junk' in the garage
:lol:
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Re: Life, the universe & everything...Atari (well, mostly)

Post by JezC »

JezC wrote: Thu Jul 30, 2020 12:48 pm One 520 seems basically ok - even the floppy worked to run SysInfo.
The other two booted to the desktop but floppies didn't work (still happy enough) so will investigate further when I can, hopefully by next week.
So, a bit more digging & one of the new additions with the non-working floppy has a damaged power cable to that floppy (no +5v)...the other one spins the drive but won't read a disc (but is fine with a Gotek - and turns out to be a 1040 too!).

Swapped the floppy from the one with the broken power lead to the other system & it works fine!
:yay: :yay2: :dualthumbup: :cheer: :thumbup: :cheers:

Enough progress for tonight...but I will try and bodge in a 5v connection for that lead over the weekend & then try that ST with the Gotek (also noticed that system has a memory upgrade installed & reports itself as having TOS 1.04...the other two are TOS 1.02).
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Re: Life, the universe & everything...Atari (well, mostly)

Post by JezC »

Ok, finally made a few minutes to bodge that cable & test the ST...it's working OK with the Gotek :D but isn't recognising the extra memory :( , just reporting as 512k.

Still, I'm more than happy with the state of these 3 new additions to the 'collection' given the price I paid...and one of them could easily become a donor for my second H4 or the H5 when that comes along...

In the meantime, I will see if I can work out why the memory expansion isn't working on this one & then hopefully the last few parts will arrive to allow me to build up the Exxos IDE v1.1 boards & fit the first of those into H4 #1.
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Re: Life, the universe & everything...Atari (well, mostly)

Post by JezC »

The (supposedly) final batch of bits to build the two IDE boards arrived today...only to reveal that I've managed to order two 84 contact PLCC sockets to fit onto PLCC pads, not the through-hole sockets that I need to fit the PCBs...
:sigh: :mad: :headbang: :cussing:

Oh well, back to the drawing board for that one...or more precisely the list of sockets on the Farnell website.

Maybe I should also order some more bits towards that elusive second H4 build...purely to qualify for the free postage of course!
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