Zogging Hell

That's an earth/ ground wire I suspect. Usually it is screwed to the RF shielding (or soldered.. better, but can make dismantling a bit tricky depending on where it is soldered). If you're getting 512k it probably isn't working at the moment, unless the on board ram has been disabled and the board is only partially working.. which seems unlikely.

Perhaps try GFA Basic rather than Hisoft if you want to make games for a base ST. Hisoft is good for apps (there is a version 2 out there btw), but is not well supported for game writing. Try http://gfabasic.net/ Not sure why you are getting an error saving to disk in STOS in emulation, have you created a blank disk image. STOS programs either need to run from STOS or you can use the STOS compiler create an executable. This page might help (manual is there) http://stos.atari.st/dload_stos.htm

Yep any Atari colour monitor will display medium and low res. Regardless of STe or STFM or whatever. I think that one is stereo as well so will support the STe's stereo output.

Hhhm, if it is failing after warming up that could be a number of things. How is the power supply for this, has it been recapped? If it is the original external power supply it could be getting a bit long in the tooth now, those caps will be on their last legs probably. They could be failing which could perhaps cause your problems with the bombs. The memory upgrade pushes into the socket between the MMU and the socket then? This might have caused the pins in the socket to fail to make proper connection when you have plopped the MMU back in. You could try gently trying to bend the pins in the socket out a bit. You did definitely put all the chips and connectors back the right way when you reinstalled didn't you? I can only assume that something has gone amiss when you reinstalled, I'd check the fitting of the MMU bit first as it can be difficult to line it up when you can't see it very well. 2.5mb makes sense, so presumably the spare slots could take you up to 4mb if you disable the onboard memory. It's not entirely unusual for STs to have some in factory alterations, which may have been simply to make the ST work, although that socket is a bit unusual and probably not done at that stage. Soldering the socket on top would have caused a lot of heat to be transferred to the memory chip underneath potentially, which could cause it to fail over time. I can't see what purpose it could actually have really in its current state, unless the original owner was going to try to do a piggy back memory upgrade, gave up after soldering the first socket and brought that memory upgrade instead. If that chip has failed you could try and disable the onboard memory (this would reduce you to 2mb), or replacing that chip if your soldering is good. Again that could be the source of your crashes.

Is it a 1mb or 512k upgrade. I notice there are empty memory chip sockets - so presumably 512k upgrade? If it is 1mb though the reason nothing works without it in could be that the internal memory has been disabled (something you would have to do with 1mb to stop the machine having 1.5mb which the ST doesn't support). Check for some snipped components near the motherboard memory. My other thought if that is not the case, is that the mounting over the MMU is to blame. I would check connections there (not pressed in correctly when you reseated it, or the socket pins aren't making good connection. I can't see how that adaptor fits over the mmu, Is it socketed and press in (i.e. pins on the adaptor push into the socket) or press on (i.e. that socket fits over a surface mounted MMU) or is it soldered on? Finally it could be the ram has gone bad, either on the upgrade board or on the motherboard, as it seems socketed on the upgrade you could try replacing that..

If you're running Atariworks either or NVDI or Speedo will be a much better option any way. Atariworks works well on the Falcon. I would probably recommend NVDI as Atariworks benefits from the increased screen redraws quite a bit.

What are you using to load the fonts? SpeedoGDOS, NVDI, or original GDOS? (the latter doesn't work).

Some quality crashes there Howabout some brief descriptions saying what was happening or what you did to get those screens? With our machines getting on a bit it could be quite useful for diagnosing problems.

You have an STFM, from the look of the motherboard, so the most you can do easily without soldering is fit TOS 1.04 (1.62 is pretty much the same anyway, but with added stuff for the STe). There were some Analogic TOS upgrades that offered solder free 2.06 upgrades for the STFM, but they are now pretty hard to find. Exxos's 2.06 upgrades look like they are for the STe only as far as I can tell from a quick look. If you have 1.0 or 1.02 in there then you could get the 1.02/ 1.04 switcher on there or just replace the ROMs already in there with 2 chip 1.04s.

There are two STe versions (1.06 and 1.62),the first 1.60 or 1.06 has a medium res bug, where it can't save a parameter in the desktop info file to boot in medium res (it can be manually entered). There are a few other bugs as well. The 1.06 or 1.60 thing is interchangeable, although the official version numbering was 1.04, 1.06 etc. Confusingly 1.62 is only 1.62 and 1.02 is also 1.2 and 1.08 iirc (the latter in some info utilities due to a mis read).

The mono select is caused by a pin on the cable/ and monitor port. If it is present then the ST boots in mono, if not then it boots in low res. If your cable doesn't have the pin, it won't boot in mono. Check the pin outs on your cable.

You'd probably need to go on Atari forum for the 'solder ball 78' stuff I might be wrong but I didn't think the composite works with STs without a modulator, but if you have another original ST without one and it does then I probably am! If you are getting key clicks when you press the keys the problem is not the ST. If not then it may well be 'solder ball 78'. It may be a memory issue, is it an expanded one? I would also pop the top and try reseating all the chips in sockets (take them out, put them back in - check orientations are the same, sometimes a press on the top might be enough)

Never heard of that happening (sounds more like something the Mac would do..!). Are you using a disk to boot from or is it just switching it on? The ST does have a bell sound, usually for error messages, but it would have to come through the monitor speakers, which would suggest the monitor is getting something. When you hold down the keys does the key click make a noise? I suspect that your tv (I'm presuming your not using a monitor) isn't liking the output from the ST. The vanilla ST (and the STF) lack a TV modulator, and really need an RGB monitor (or something that can handle that signal).

You would need to run HS Modem to recognise the mod anyway, so that is essential (it would be worth doing even without the mod as the serial code in TOS is buggy). I suspect another problem will be how the MIDI program handles things. A few sequencers were set up to make sure the MIDI timing got preference over everything else, including the GUI, so whether they would be programmed to cope with the CPU requirements of pumping data out of the serial port as well I don't know.

I just about remember ST Format or ST Review having a DIY serial upgrade with parts available from Maplins (UK electronics retailer), you might want to flip through some of their back issues (it would be in the more recent, 40+ ST Formats if it is in there). I can't imagine that needed programmed gals. Iirc it was just doubled the speed (to 38400 ish), and required some soldering and possibly a track cut or two. 38400 is about the tops an ST will go without acceleration. I can't remember the speed the MIDI ports actually run at but vaguely recall they are about the same speed.

From memory I believe I played Space Gun at least on a Phillips monitor, which has the same internals as the Atari one. Any CRT should be fine I think.

You'd have to be a sadist to run a full Freemint setup on a basic ST, it's like running Windows 3.1 on a 286 PC, possible but not much fun

If you can get a switcher, that would be best. TOS 2.06 is far better to work with on a day to day basis, but has issues with quite a few games (particularly early ones). I have 2.06 and 1.02 in my STFM which gives the best of both worlds. I don't often swap back, but if I do need to then it's there if I need it. If you don't play games that much then imo its a no brainer, get 2.06 in there, particularly as it is just a ROM swap.

Yeah that was what I thought you meant The switch itself could be on the way out, rather than anything else, and is no longer making good contact. You could try some contact cleaner in there I guess. I just meant that if the switch itself is knackered and if you will have to go to the trouble of replacing it eventually, it might be less hassle to get a new supply.

I'm not sure I read this correct, but the way I read that the mouse probably won't work in the other direction either as the pins are different from the trackball so not a great test. https://www.exxoshost.co.uk/atari/last/storenew/will probably one of the best places to get an adaptor, although I'm not sure what the shipping will be to Canada. I would plug it in the ST, take the top off and try rotating the wheels inside on the GEM desktop. In the short term you can use alternate and the arrow keys to move the mouse pointer around and alternate and insert to click. I would be careful with that power switch, it does sound like it is on the way out. You could try resoldering the wires that connect to it from the psu itself, but if the switch itself is going you might be on a looser. You might be able to get a dead donor PSU to swap over the switch from that, but the PSU will probably need recapping at this stage in its life anyway. Alternatively if you are comfortable, you could adapt a PicoPSU to run the ST, but it is not a completely straightforward task. If you are ordering from Exxos he also does replacement PSUs, which might save the hassle..

I'd check the continuity on the solder points on the keyboard mouse port (remove the keyboard from the ST and flip it over - I can't remember whether you also have to remove all the tiny screws and totally dismantle the keyboard to see the solder joints - its been a while) as a first step and check for visible breaks in the solder joints on the mouse port. Your 800 trackball won't work without some modifications as it is wired up differently, some Amiga third party mice will work if they have a Atari / Amiga switch. If the keyboard looks ok it may be the mouse is faulty. I would remove the top (of the mouse) with the ST on and physically rotate the two wheels inside and see if that works on the desktop. There was also a virus that caused the mouse to head northwards iirc (Ghost?). You might want to check your disks with UVK if the hardware checks out. Just don't use it with any original games as they always look like viruses to a lot of virus checkers.

Actually to make matters worse there seem to be several types of face plate for various mechanisms, original factory fitted Chinon drives are slightly different, and there are others. I suffered from this, when I was young and naive I thought my floppy drive was dying so sent it to be replaced. I had the sense to ask for the old drive back as well as the new one, but it came back without the face plate. I later discovered the drive was actually fine, but trying to find another face plate to fit has proved to be a nightmare (presumably why it was half inched in the first place). I have a collection of about eight, several different, and do any fit this drive.. no...

It (the PSU) is held in by two to fours screws on motherboard, if you open the case up and remove the top metal shielding (this is held in place by a mixture of screws and metal tabs - which you need to twist straight with some pliers) you will see the psu at the back left. The screws holding it in place are on the feet of the metal 'stand' the PSU sits on. Undo these and then unplug the power cable from PSU to the motherboard (AT style plug). The PSU can then be removed by some gentle manoeuvring, although it is a bit tricky as it will not like coming out at the back where the PSU external power lead and power switch go through the case - it can be done however, just don't force anything. To make this easy you can remove the whole motherboard but that can be more faff. You then simply reverse the procedure to put the new one in.

Could well be, if you can swap the drive and have the same results then I would suggest a flakey PSU is the problem, and as Umberto said, will either need replacing or recapping.

That's a bit harsh, I've had them in several STs for years without any problems at all, overall I would say they are pretty solid if they are installed correctly (and don't want to run any other upgrades like a speed booster) The only one I had problems with was the fit socket over the soldered MMU type. One literally popped off after some time, killing itself.