Looks like I'll be getting a Mega ST4 soon

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rubber_jonnie
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Re: Looks like I'll be getting a Mega ST4 soon

Post by rubber_jonnie » Fri Oct 18, 2019 1:13 pm

Eiffel is here, and I have a week off next week (Well a weeks holiday, I don't think I can class it as off!)

Hopefully I'll get some time though and I can get this puppy up and running.
IMG_20191018_130948.jpg
IMG_20191018_130948.jpg (285.36 KiB) Viewed 651 times
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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PhilC
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Re: Looks like I'll be getting a Mega ST4 soon

Post by PhilC » Fri Oct 18, 2019 1:23 pm

rubber_jonnie wrote:
Fri Oct 18, 2019 1:13 pm
Eiffel is here, and I have a week off next week (Well a weeks holiday, I don't think I can class it as off!)
So do I but the wife wants to decorate. :roll: :cry:
If it ain't broke, test it to Destruction.

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PaulJ
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Re: Looks like I'll be getting a Mega ST4 soon

Post by PaulJ » Fri Oct 18, 2019 1:43 pm

rubber_jonnie wrote:
Fri Oct 18, 2019 1:13 pm
Eiffel is here, and I have a week off next week (Well a weeks holiday, I don't think I can class it as off!)
Hopefully I'll get some time though and I can get this puppy up and running.
I think I like your form factor better. The older revision is longer and narrower.

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rubber_jonnie
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Re: Looks like I'll be getting a Mega ST4 soon

Post by rubber_jonnie » Fri Oct 18, 2019 5:21 pm

PhilC wrote:
Fri Oct 18, 2019 1:23 pm
rubber_jonnie wrote:
Fri Oct 18, 2019 1:13 pm
Eiffel is here, and I have a week off next week (Well a weeks holiday, I don't think I can class it as off!)
So do I but the wife wants to decorate. :roll: :cry:
I feel your pain. I've got to re grout and seal our shower, go and take a load of crap to the dump, help clear out the spare room ready for the 2 desks I need to collect from my old office, and make another trip to the dump. :(

High point is fibre to the premises broadband installation on Thursday :)
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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rubber_jonnie
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Re: Looks like I'll be getting a Mega ST4 soon

Post by rubber_jonnie » Fri Oct 18, 2019 5:24 pm

PaulJ wrote:
Fri Oct 18, 2019 1:43 pm
rubber_jonnie wrote:
Fri Oct 18, 2019 1:13 pm
Eiffel is here, and I have a week off next week (Well a weeks holiday, I don't think I can class it as off!)
Hopefully I'll get some time though and I can get this puppy up and running.
I think I like your form factor better. The older revision is longer and narrower.
Yeah, it is pretty dinky. It is the light version BTW so only one Atari joystick/mouse port, but I have to say it arrived very quickly considering Olivier is in Europe.Basically it only took 6 days to arrive.
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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Re: Looks like I'll be getting a Mega ST4 soon

Post by rubber_jonnie » Sat Oct 19, 2019 1:20 pm

So today worked out pretty well, as I discovered a very small thing that was having a fairly annoying side effect, that being the machine misbehaving.

It's not so obvious in pic no 1, but have a look at the second EPROM back:

IMG_20191019_120509.jpg
IMG_20191019_120509.jpg (313.81 KiB) Viewed 609 times

I only noticed as I caught it in the light just right. Pic no 2 shows just what the problem was:

IMG_20191019_120554.jpg
IMG_20191019_120554.jpg (173.56 KiB) Viewed 609 times

And after some gentle manipulation, I plugged it back in and everything seemed much better :)

The list of fixes so far is:

1. Replaced mising sound chip. Channel A is silent under test, but B & C work fine. I'll test with another chip in case I have a duffer, but I suspect the problem is one of the nearby PCB traces that was damaged which still needs work.
2. Replaced missing Blitter. This all seems to test out fine.
3. Tweaked the contacts in the MMU socket, now I seem to be seeing 4MB ram all the time.
4. As above, fixed bent EPROM pin.
5. As the floppy connector disintegrated in my hands,I fitted a new one. Floppy works just fine now.

So what's left?

1. Fix the sound chip channel A problem.
2. Even with Eiffel, I can't get the mouse to work properly (KB is fine), either with a normal Atari mouse, or a PS/2 mouse. Could be a dodgy connection on the Megas RJ11 socket, I just don't know. I figure I need to wire up a spare ST KB direct to the board, see if that works.
3. Make a new wiring harness for the battery compartment.

So good overall progress, I think it'll be fully operational pretty soon. Once it is all running stably, I will look at some options, like a PAK install, possibly an internal IDE adaptor and maybe I'll even look at installing the DVI adapter board I have from Simon Monson. That would be quite a machine :)
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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frank.lukas
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Re: Looks like I'll be getting a Mega ST4 soon

Post by frank.lukas » Sat Oct 19, 2019 2:04 pm

When the keyboard are working fine with the Eiffel so the mouse must be working too. Your PS/ 2 mouse are faulty. On the Eiffel Joystick port you can not connect a mouse I think it is joystick only.

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rubber_jonnie
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Re: Looks like I'll be getting a Mega ST4 soon

Post by rubber_jonnie » Sat Oct 19, 2019 2:30 pm

frank.lukas wrote:
Sat Oct 19, 2019 2:04 pm
When the keyboard are working fine with the Eiffel so the mouse must be working too. Your PS/ 2 mouse are faulty. On the Eiffel Joystick port you can not connect a mouse I think it is joystick only.
Actually, you're right Frank, I just re-read Olivier's notes and I may have miss-read it originally, but not really a problem, I just need to go through my boxes of stuff to find a proper PS/2 mouse.
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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Re: Looks like I'll be getting a Mega ST4 soon

Post by stephen_usher » Sat Oct 19, 2019 2:34 pm

Indeed, it's an exact replica of the Joystick 1 port on the ST(F)(M) so doesn't support the mouse.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.

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Re: Looks like I'll be getting a Mega ST4 soon

Post by rubber_jonnie » Sat Oct 19, 2019 3:24 pm

Audio problem resolved, all 3 channels are now audible on test, seems that A & B are next to each other on the chip, and are supposed to be tied together, but the pad for channel A, which should have a track to the pad next door for channel B was gone. So it's now bodge wired.

As soon as I finish my coffee, I'll get the wiring harness made for the batteries.

One last final item is some FDD standoffs, but since I designed some already, I can 3d print them unless I have some in a box somewhere.

Then it's time for a mouse hunt!!
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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