The latest Addition to the ST Family

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rubber_jonnie
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The latest Addition to the ST Family

Post by rubber_jonnie »

This is aimed at @JezC as he's been asking for pics of my 'new' Big Button STFM.

It's all really rather grubby, with all kinds of stuff in the mouse:

IMG_20210914_131500.jpg
IMG_20210914_131500.jpg (173.95 KiB) Viewed 2086 times

Which now cleaned, works rather better than I had anticipated :)

Inside it's rather grubby too:

IMG_20210915_115448.jpg
IMG_20210915_115448.jpg (254.35 KiB) Viewed 2086 times

And a quick peek under the hood shows it as being my least favourite motherboard:

IMG_20210915_115543.jpg
IMG_20210915_115543.jpg (148.8 KiB) Viewed 2086 times

And an empty spot for the Blitter. Luckily I have a recovered socket I can fit here :)

Quite a bit of cleaning required and I'll drop a re-capped PSU in for testing purposes.
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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JezC
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Re: The latest Addition to the ST Family

Post by JezC »

@rubber_jonnie Thanks for the pictures!
I've not seen that motherboard revision in a case with the long floppy button before...

Mine are all the older ones without a blitter footprint or the early 70789 revisions (so RAM under the PSU).

What are your plans for it (after the deep clean)?
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rubber_jonnie
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Re: The latest Addition to the ST Family

Post by rubber_jonnie »

JezC wrote: Wed Sep 15, 2021 12:28 pm @rubber_jonnie Thanks for the pictures!
I've not seen that motherboard revision in a case with the long floppy button before...

Mine are all the older ones without a blitter footprint or the early 70789 revisions (so RAM under the PSU).

What are your plans for it (after the deep clean)?
That Mobo seems a bit new for a long button machine, wondering if it's a replacement?

Ideally I'll take it to 1MB, and at least add a Blitter socket. I should also decide which of my machines might get an H4 board.
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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rubber_jonnie
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Re: The latest Addition to the ST Family

Post by rubber_jonnie »

@JezC Some more pics for you:

Mainboard:

IMG_20210915_164031.jpg
IMG_20210915_164031.jpg (438.48 KiB) Viewed 2047 times

Chinon FDD:

IMG_20210915_164055.jpg
IMG_20210915_164055.jpg (169.21 KiB) Viewed 2047 times

Mainboard is surprisingly clean, and I suspect a replacement. C103253 Rev1 seems rather late to be in this machine, and though there aren't any add ons, the Shifter is socketed which is nice. The state of the mainboard just doesn't seem to match the machine, and the internal shield tabs have clearly been played with

I'll need to have a look on the underside for signs of rework, but nothing obvious at present.
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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JezC
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Re: The latest Addition to the ST Family

Post by JezC »

Thanks for the additional pictures @rubber_jonnie !

Looks like all the custom chips are socketed! I think there are only one or two of those in my whole collection..most have the DMA soldered in, a few (mostly the newer ones) have the Shifter soldered in too!

With it being just the two ROMs I'm expecting you've got either TOS 1.02 or 1.04 - don't think I've ever seen the two ROM solution for TOS 1.00...but given how odd some of the combinations are out in the wild, pretty much anything is possible!

Do you have much success soldering those SMT RAMs?
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rubber_jonnie
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Re: The latest Addition to the ST Family

Post by rubber_jonnie »

JezC wrote: Wed Sep 15, 2021 9:55 pm Thanks for the additional pictures @rubber_jonnie !

Looks like all the custom chips are socketed! I think there are only one or two of those in my whole collection..most have the DMA soldered in, a few (mostly the newer ones) have the Shifter soldered in too!

With it being just the two ROMs I'm expecting you've got either TOS 1.02 or 1.04 - don't think I've ever seen the two ROM solution for TOS 1.00...but given how odd some of the combinations are out in the wild, pretty much anything is possible!

Do you have much success soldering those SMT RAMs?
DMA is socketed too, but I was busy playing round with my Octane too and missed it!

I'll likely power it up tomorrow and run the diag cart on it to see what's what when I've cleaned up a bit more.
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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rubber_jonnie
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Re: The latest Addition to the ST Family

Post by rubber_jonnie »

JezC wrote: Wed Sep 15, 2021 9:55 pm Do you have much success soldering those SMT RAMs?
In short, no, but I reckon I could do a better job now I have more hot air experience :)
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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rubber_jonnie
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Re: The latest Addition to the ST Family

Post by rubber_jonnie »

@JezC

The new boy got a bit of a test drive today:

IMG_20210918_164504.jpg
IMG_20210918_164504.jpg (305.93 KiB) Viewed 1930 times

But looks like we have a DMA problem, as it won't format or read floppies and doesn't see my UltraSatan either. I'll look at getting the bus resistor packs done as I have loads of spares, but as the DMA is in a socket, I suspect it may well have been replaced, so the board will have to come out and have the rework checked just to be sure.

About time I had another ST to fix!!

TOS is 1.02, I expect I'll be upgrading to 1.04 too.
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: The latest Addition to the ST Family

Post by stephen_usher »

I wonder if the DMA ever gets fried by static from the port on the rear. The ACSI isn't buffered is it?
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: The latest Addition to the ST Family

Post by rubber_jonnie »

stephen_usher wrote: Sat Sep 18, 2021 6:04 pm I wonder if the DMA ever gets fried by static from the port on the rear. The ACSI isn't buffered is it?
I think it is directly connected, so no buffering. The ACSI socket is not great either TBH, so I may swap it out as I have spares. It is pretty much stock dead DMA territory IMHO, but I do have some spares I think. Last time I had FDD problems, on a Mega IIRC, that was a DMA too. As I mentioned, it's socketed, so I will give that a good look over.
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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