the official Channel F thread!

[3DMAZE]

Ooh, can't wait!

 

@Sonaru Thursday counts as the weekend right? Got the page up for the flashcart! For anyone else, feel free to comment in that thread or PM me if you think you'd be interested, and I can add you to the list

 

https://forums.atariage.com/topic/343225-fairchild-channel-f-flashcart/

[Dopy25]

Does anyone know if a cartridge will bypass a bad Program Storage Unit in a system 1?

 

I have a system 1 that I believe has a bad PSU (program storage unit in this case). The chip is labeled SL90026. From what I can tell, this and 90025 are the chips that hold the built in games. Can anyone confirm?

 

I think this chip is bad because it gets REALLY hot. Too hot to touch for a good while after it's powered off. 

 

Also can anyone fill me in on if these need to be replaced in pairs? If I find another sl90026, can I swap it in? How about another part number but also the first chip in the program storage unit set?

 

I get a black screen and nothing else. I do kind of hear a splash of static from the speaker but only for a second at boot. 

 

I have zero cartridges to test the theory. Anyone have a spare that isn't very popular? 

[3DMAZE]

@Dopy25 The PSUs contain the BIOS and built in games. Some (all?) games use some of the functions in the BIOS, and would have problems if it wasn't there. If it's getting hot, there's probably a short somewhere (could be in the chip). I'd remove the chip to avoid damaging anything. They shouldn't need to be replaced in pairs, just one ought to work. Unfortunately, they contain ROM data, so you can't just buy it as a separate part. This chip can only be found inside another channel F. I suppose you could buy a broken Channel F and salvage it's parts?

 

Or if someone knows which games don't use BIOS functions past address 0x400, you could buy one of those

 

Edited November 5, 2022 by 3DMAZE

[Dopy25]

7 minutes ago, 3DMAZE said:

@Dopy25 The PSUs contain the BIOS and built in games. Some (all?) games use some of the functions in the BIOS, and would have problems if it wasn't there. If it's getting hot, there's probably a short somewhere (could be in the chip). I'd remove the chip to avoid damaging anything. They shouldn't need to be replaced in pairs, just one ought to work. Unfortunately, they contain ROM data, so you can't just buy it as a separate part. This chip can only be found inside another channel F. I suppose you could buy a broken Channel F and salvage it's parts?

Ok so they don't need to be replaced in pairs, but would a part 2 of the 2 part PSU from another part number be a suitable replacement? 

 

Example:

 

The bad one is 90026 (I'm guessing can't replace with a 90025)

 

But could I replace it with (something I'm going to makeup here because I don't know)

 

LS91026 (as long as it coincides with a 91025)?

 

Or must it be an exact LS90026 that I replace it with?

 

At this point I'm sure it's a bad chip. The 90025 in the system does not get hot. All chips receive the accurate voltage according to the diagram I found for each. They all put 12 & 5 volts on VCC and VDD (I think it is). Even there bad one gets the right voltages. This is why I figured the chip itself is bad. 

 

I'm hoping someone here might have a spare from their own parts console.

 

Edited to clarify part 2. I assume 90025 is part 1 and 90026 is part 2.

 

I read somewhere (I'll find it again if necessary) that carts work without the onboard games chip and that the specific chip was the PSU set. Are you absolutely certain that nothing will work without it?

Edited November 5, 2022 by Dopy25

[3DMAZE]

The first chip(LS90025) contains the top half of the BIOS/built-in games, and the second chip (LS90026) contains the 2nd half, so they aren't interchangeable. That said, the BIOS is basically the same for all the channel F variations that I know of, so yes, you should be able to use the 2nd chip of any variant. The LS90025/LS90026 & SL31253/SL31254 pairs are the two I know of

Edited November 5, 2022 by 3DMAZE

[Dopy25]

33 minutes ago, 3DMAZE said:

The first chip(LS90025) contains the top half of the BIOS/built-in games, and the second chip (LS90026) contains the 2nd half, so they aren't interchangeable. That said, the BIOS is basically the same for all the channel F variations that I know of, so yes, you should be able to use the 2nd chip of any variant. The LS90025/LS90026 & SL31253/SL31254 pairs are the two I know of

That makes sense. I can't find the thread now that mentioned carts should boot without it but I know I read it somewhere when I was trying to find out info. I should have bookmarked it. Oh well. 

 

The only other console I have access to right now is a system 2 and that chip is not socketed, and is under the cart slot mechanism. It also appears there's only one chip for the PSU on the system 2. Man. For being an early system, they sure used random parts and board variations. It's weird, especially if the bios are all the same.

 

I'll look again in the system 2, and see what happens. I really hate to desolder 2 of those suckers just to test. Plus the system 2 has garbled graphics so it's not for sure those would even work.

[Dopy25]

Ok at this point, I believe it to be bad RAM. Does anyone know where to source ram or a ram mod for the Channel F? I've seen multiple posts about ram, but nothing conclusive. There were actually a few quite contradictory. 

 

Has anyone here successfully replaced ram that was not sourced from another console? If so, can you point me in the right direction?

[3DMAZE]

19 minutes ago, Dopy25 said:

Ok at this point, I believe it to be bad RAM. Does anyone know where to source ram or a ram mod for the Channel F? I've seen multiple posts about ram, but nothing conclusive. There were actually a few quite contradictory. 

 

Has anyone here successfully replaced ram that was not sourced from another console? If so, can you point me in the right direction?

Yes, I've replaced broken RAM on my Channel F before. Though mine was a model 1.5 (essentially a model 2 in a model 1 case). I bought a few Mostek MK4027N-1 chips for $3 on eBay, to replace the factory DRAM chips labeled "330470", and it worked perfectly. I only replaced one of the four chips, and it worked fine, so you should have no issues mixing them with the ones already installed (though some folks have). MK4096, MK4027, and MK4015 chips should all work, but don't quote me on that. If you need help with anything let me know!

Edited November 11, 2022 by 3DMAZE

[e5frog]

@Dopy25

Yes, 4027 is recommended.

https://channelf.se/veswiki/index.php?title=VRAM

Edited November 11, 2022 by e5frog

[Dopy25]

Thank you both! Excellent starting point to get roaring on. 

 

I'm not familiar with different types of packages of chips. Would these work?

 

https://www.ebay.com/itm/175404085893?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=dQGtIlKTQ86&sssrc=2349624&ssuid=tc6gnTeJTDi&var=&widget_ver=artemis&media=COPY

[3DMAZE]

@Dopy25 The last letter is the package type. It's fine as long as it's one of (J = Ceramic, K = Tin side-brazed ceramic, N = Plastic, P = Ceramic side-brazed, T = Ceramic DIP with transparent). And the last digit is for speed, but any of the MK4027-1/2/3 should be fast enough.

 

That link looks good to me! I got my 5 from this seller whose chips are slightly cheaper per unit, but whether it's a better price over all will depend on your shipping costs

[Dopy25]

@3DMAZE perfect. Thank you! I saw that one too even when I was looking but the shipping makes them cost around the same for the same amount. Honestly I'll probably be better off just buying a few right now so I know I have a good set, and checking the rest of them to get a good set in the second console. Maybe I'll buy 5 as well.

 

Here is the model 1 that I have:

 

Would this be like the one you referred to as a 1.5? 

[3DMAZE]

Sounds like a plan! Yep, that's the same model I have. It's easily distinguishable by it's vastly smaller chip count. In case it helps, here's one that's labeled (German version):

 

Edited November 11, 2022 by 3DMAZE

[Mikebloke]

This is me:

 

https://www.ebay.co.uk/itm/265988203276

 

Unfortunately I'm in need of money asap otherwise I would have thrown it out to offers - the ebay fees these days are killer, but its the only marketplace where I think it'll get sufficient reach. The price point is based on what similar job lots have gone for post pandemic the last couple of years.

 

I'm keeping my console, so development of new games will continue! But as I've been posting in other parts of this site for the last year I'm at the point now where I'm ok to "let it go". Got lots more early gen games coming up for other systems too, but this is the big one.

[Ashevent]

8 minutes ago, Mikebloke said:

This is me:

 

https://www.ebay.co.uk/itm/265988203276

 

Unfortunately I'm in need of money asap otherwise I would have thrown it out to offers - the ebay fees these days are killer, but its the only marketplace where I think it'll get sufficient reach. The price point is based on what similar job lots have gone for post pandemic the last couple of years.

 

I'm keeping my console, so development of new games will continue! But as I've been posting in other parts of this site for the last year I'm at the point now where I'm ok to "let it go". Got lots more early gen games coming up for other systems too, but this is the big one.

Best of luck on your sale. I hope you are able to sell fast. great collection 

[+jgkspsx]

So I somewhat unwisely sprang for a copy of Pro Football that I was offered at a slight discount. It arrived yesterday. When I first opened the package I was struck by the (lack of) print quality on the label. It looks like an inkjet printing with lamination.

 

 

Then I realized the label was just pasted over another label.

 

 

The end label was falling off and I noticed the same thing - it was separating.

 

Yes, the original end label is a Democart label.

 

So, is this for real? Did Zircon really harvest old Democarts and make very crappy labels in the last days of Channel F distribution? Or is this some kind of crazy bootleg?

 

If I take the cartridge apart, am I gonna regret it?

[+jgkspsx]

Well, I guess that answers that: 

I swear my other Zircon labels are much more nicely made, though.

 

 

[e5frog]

Yes, I've had those as well, swap boards with a new one, make it a working cart and put it in the collection - or sell it. 
Then put the #24 labels on some cheaper donor cart.
It's more common to find 1-5 instruction labels or 12 as bottom label. 

 

  

Edited November 14, 2022 by e5frog

[+jgkspsx]

13 hours ago, e5frog said:

Yes, I've had those as well, swap boards with a new one, make it a working cart and put it in the collection - or sell it. 
Then put the #24 labels on some cheaper donor cart.
It's more common to find 1-5 instruction labels or 12 as bottom label.  

So do you think it’s fake? It’s hard to believe somebody would fake a democart and not sell it as a democart.

 

How tricky is the spring assembly? I don’t see any videos online of a Videocart teardown.

 

EDIT: pretty tricky according to the redoubtable Nicole Express: https://nicole.express/2021/the-most-unfair-child.html

[e5frog]

16 hours ago, jgkspsx said:

So do you think it’s fake? It’s hard to believe somebody would fake a democart and not sell it as a democart.

 

How tricky is the spring assembly? I don’t see any videos online of a Videocart teardown.

 

EDIT: pretty tricky according to the redoubtable Nicole Express: https://nicole.express/2021/the-most-unfair-child.html

No no, it's not fake, all of those are genuine labels, you have a Democart that they swapped board in and put other labels on top.

I suggest you put the Democart labels back on the shell (since it's marked DX and likely also has writing in the hatch) and then make a working board to put in it - and of course be clear that the circuitboard has been replaced if you're selling it.

 

#24 labels and boards fits fine on another shell. 

 

If you hold the hatch in place while unscrewing the last screw (which should be one of the ones closest to the hatch) it will not jump away and you can see how the springs are mounted. Take the board out and then slowly release the hatch.
Remounting the flat cables for the cartridge holder on a Fairchild Video Entertainment System after disassembly - that's tricky. Opening and closing a Videocart is not tricky... possibly if you need to be careful not to crease the edge label. 

 

[+atari2600land]

Go on to Google today (Dec. 1, 2022) and I think you'll be surprised...

[e5frog]

Christmas lights Google logo... what else?

[Arlasoft]

1 minute ago, e5frog said:

Christmas lights Google logo... what else?

On mine it's a Jerry Lawson tribute, with a little playable platform game editor. Slightly misleading as to what the Channel F was capable of but hey! 

[e5frog]

Swedish google sucks apparently. 
VPN to the US and it pops up - animated as well. 

Edited December 1, 2022 by e5frog

[CatPix]

Works here too