New project: An ACT Apricot F1 "barn find"

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stephen_usher
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Re: New project: An ACT Apricot F1 "barn find"

Post by stephen_usher »

If you can make it then it'd be great to meet you.
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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rubber_jonnie
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Re: New project: An ACT Apricot F1 "barn find"

Post by rubber_jonnie »

stephen_usher wrote: Sun Sep 12, 2021 6:42 pm If you can make it then it'd be great to meet you.
I'll see what I can do :)
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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stephen_usher
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Re: New project: An ACT Apricot F1 "barn find"

Post by stephen_usher »

The memory upgrade PCBs have arrived.

IMG_2380.jpg
IMG_2380.jpg (378.77 KiB) Viewed 1630 times

The hardest thing I need to do is solder SIOC surface mount SRAM on the other side, which has incredibly fine pins!
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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rubber_jonnie
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Re: New project: An ACT Apricot F1 "barn find"

Post by rubber_jonnie »

stephen_usher wrote: Mon Sep 13, 2021 1:03 pm The memory upgrade PCBs have arrived.
IMG_2380.jpg
The hardest thing I need to do is solder SIOC surface mount SRAM on the other side, which has incredibly fine pins!
Very nice :)
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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stephen_usher
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Re: New project: An ACT Apricot F1 "barn find"

Post by stephen_usher »

The board passes its initial electrical and physical tests.

I fitted a connector to an unpopulated board to do a sanity check. It fits correctly, +5V and GND are in the correct places and the machine still boots, which is a bonus. I've not checked any of the data or address lines yet but it's a good start.

IMG_2381.jpg
IMG_2381.jpg (72.42 KiB) Viewed 1611 times

I also tried the 8 pin DIN socket but that's not so good news. The pins are FAR larger than the holes I specified. I'm going to have to file the pins down for these boards and modify the footprint design.
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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stephen_usher
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Re: New project: An ACT Apricot F1 "barn find"

Post by stephen_usher »

Fitted everything except for the GAL and memory and everything seems to be operating correctly.

The address lines are latching, the control lines are doing what seems to be correct and, more importantly, no magic smoke. The machine still boots normally.
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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stephen_usher
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Re: New project: An ACT Apricot F1 "barn find"

Post by stephen_usher »

GAL programmed and installed.

I'm going to need a bodge wire as the GAL programming software doesn't like a logic high output on pin 19 so I've had to switch to pin 15.

Still, I'm seeing activity on the selection line during the initial RAM test stage of the ROM along with data line activity at the same time.

So, bodge wire and SRAM (eek!) to do tomorrow evening.
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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stephen_usher
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Joined: Mon Nov 13, 2017 7:19 pm
Location: Oxford, UK.
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Re: New project: An ACT Apricot F1 "barn find"

Post by stephen_usher »

This is the scary surface mount device pad...

IMG_2383.jpg
IMG_2383.jpg (39.67 KiB) Viewed 1594 times

Still, the board looks OK in general. The noise levels on the traces are fine, so a 4 layer board is not needed.

IMG_2382.jpg
IMG_2382.jpg (92.11 KiB) Viewed 1594 times
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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JezC
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Re: New project: An ACT Apricot F1 "barn find"

Post by JezC »

@stephen_usher That's a similar footprint to all the parallel Flash devices we're using on our products...as/when we can get hold of them!

Our repairs guys can swap the chips off one board & onto another in mere minutes with almost no problems...I'm never likely to get anywhere near their levels of expertise!

Good luck when you attempt to solder that one...and stay off the coffee for a couple of hours beforehand ;)
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stephen_usher
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Re: New project: An ACT Apricot F1 "barn find"

Post by stephen_usher »

Hehe. Yeah! It's going to be "fun"!
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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