I'm a bit gutted...
I will spend some time with it to see if there are shorts I may have missed. Might have to remove IC's to see if there is anything bridged underneath.
It's long overdue - Cosmac Elf II build
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rubber_jonnie
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Re: It's long overdue - Cosmac Elf II build
I will spend some time with it to see if there are shorts I may have missed. Might have to remove IC's to see if there is anything bridged underneath.
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...
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: It's long overdue - Cosmac Elf II build
Could be a "phantom short" caused by flux which has become conductive.
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.
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: It's long overdue - Cosmac Elf II build
Possibly, I need to have a good look but I did give it a damn good clen.stephen_usher wrote: Thu Apr 30, 2026 6:15 pm Could be a "phantom short" caused by flux which has become conductive.
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...
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: It's long overdue - Cosmac Elf II build
So, I have an option for the CDP1861 replacement 
I found an earlier incarnation that uses a bigger PCB and through hole components, so I've ordered those via a project on PCBWay so at least the creator will get something back.
In the meantime I do wonder if there is a short somewhere in the PCB from the solder paste I used, so I think I'll use a spare PCB and transfer over the components and either hand solder or hot air solder them on but not using solder paste.
No harm doing so, and what I might do is remove one IC at a time to see if a particular one is causing the machine to hang.
Also, my expansion slots are in the UK so that should be coming soon
I found an earlier incarnation that uses a bigger PCB and through hole components, so I've ordered those via a project on PCBWay so at least the creator will get something back.
In the meantime I do wonder if there is a short somewhere in the PCB from the solder paste I used, so I think I'll use a spare PCB and transfer over the components and either hand solder or hot air solder them on but not using solder paste.
No harm doing so, and what I might do is remove one IC at a time to see if a particular one is causing the machine to hang.
Also, my expansion slots are in the UK so that should be coming soon
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...
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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HigashiJun
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Re: It's long overdue - Cosmac Elf II build
Cannot wait seeing the final result.
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rubber_jonnie
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Re: It's long overdue - Cosmac Elf II build
Me either!
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...
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: It's long overdue - Cosmac Elf II build
Well the connectors arrived today and they look spot on:
They aren't soldered in yet as I've been in London all day, but they fit perfectly so pleased with the result. I think I'll wait until I have one of the expansion boards before I solder them all in as with 86 pins each, that's a lot of soldering if the expansion cards don't fit!!!
The PCB's for the alternate CDP1861 are nearly done, 93% according to the order so fingers crossed I'll have those relatively quickly as I did cheap out on the postage
EDIT: PCBs just shipped.
- IMG20260506220030.jpg (346.71 KiB) Viewed 707 times
They aren't soldered in yet as I've been in London all day, but they fit perfectly so pleased with the result. I think I'll wait until I have one of the expansion boards before I solder them all in as with 86 pins each, that's a lot of soldering if the expansion cards don't fit!!!
The PCB's for the alternate CDP1861 are nearly done, 93% according to the order so fingers crossed I'll have those relatively quickly as I did cheap out on the postage
EDIT: PCBs just shipped.
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...
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: It's long overdue - Cosmac Elf II build
Well the alternate CDP1861 boards arrived today:
As I'm away next week it'll probably mean I won't be able to build until I get back, and I'll be away 10 days...
I guess we'll all just have to be patient
- IMG20260515141109.jpg (261.54 KiB) Viewed 591 times
As I'm away next week it'll probably mean I won't be able to build until I get back, and I'll be away 10 days...
I guess we'll all just have to be patient
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...
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: It's long overdue - Cosmac Elf II build
Ooops, paerhaps patience isn't my thing...
Unfortunately whilst I may have the GALs I'm not sure about the rest, so that will have to wait until i get back from hols.
- IMG20260515161013.jpg (288.4 KiB) Viewed 583 times
Unfortunately whilst I may have the GALs I'm not sure about the rest, so that will have to wait until i get back from hols.
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...
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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HigashiJun
- Posts: 2388
- Joined: Fri Jun 19, 2020 7:21 am
- Location: Tokyo
Re: It's long overdue - Cosmac Elf II build
Enjoy your holiday !