SIDE3 only running loader from SDX on 1200XL

[+x=usr(1536)]

Just found a weird one.  SIDE3 is running firmware 0.40; the 1200XL in question is mostly stock except for a UAV and +5V SIO mod.  One of Dropcheck's 1200XL Cartridge Port Extensions is in use to accommodate the SIDE3's immense girth

 

Basically, the 1200XL will not boot straight to the loader.  It works fine if you boot to SDX then drop into the loader from there using the CAR command, but try as I might, with the switch in the up position, all I can expect is a black screen.  Note that this is not black like ANTIC is disabled; it's black like the 1200XL is still generating an image, it's just all black.

 

At this time I don't believe the cartridge port extension to be part of the problem since other cartridges that I've tried in it (Rev. A BASIC, Star Raiders, Donkey Kong) all work fine.

 

Is anyone else seeing this?  I did some searching and checked the documentation, but couldn't find a mention of it being expected (or otherwise) behaviour.

Edited July 25, 2021 by x=usr(1536)

[flashjazzcat]

Try replacing 74LS08 with 74F08. This is the exact issue (booting to a black screen) which this modification has fixed on half a dozen machines which have been through my hands.

 

[+x=usr(1536)]

Thanks for that; I'll add a couple to my next component order.  Much appreciated!

[flashjazzcat]

Just now, x=usr(1536) said:

Thanks for that; I'll add a couple to my next component order.  Much appreciated!

Let us know if it works. I actually had to do this on a 1200XL which was here a few months back.

 

[+x=usr(1536)]

Now that you've mentioned it, I think I even remember you bringing this up in one of your videos.  Either way, I'll report back.  It'll likely be a week or two before I'm ready to order more parts, FWIW.

[+DrVenkman]

43 minutes ago, flashjazzcat said:

Try replacing 74LS08 with 74F08. This is the exact issue (booting to a black screen) which this modification has fixed on half a dozen machines which have been through my hands.

 

I did this for one of my 1200XLs awhile back - my "Ugly Duckling" that I repaired and restored from a terrible state of decay and disrepair. It's my daily-driver XL these days, with an Ultimate 1MB, UAV and SIDE3 now.  Here's an example of the buffered Phi2 clock signal as it looked from the stock vintage 74LS08.

 

 

And here's the signal with a newly-made 74F08.

 

 

The signals are superficially similar, as they should be. This is a buffer chip and is designed to "square off" the base Phi2 as generated by SALLY on pin 39. But note the difference in the rise time (46ns initially, 40ns with the newer chip) but especially in the fall time (51ns to start, dropping to 30ns with the new chip).

 

Anything the triggers off the falling edge of the BPhi2 signal will be affected, hopefully positively, by the change. 

 

 

[+x=usr(1536)]

On 7/25/2021 at 1:12 PM, flashjazzcat said:

Let us know if it works. I actually had to do this on a 1200XL which was here a few months back.

The 74LS08 has been replaced with a 74F08.  SIDE3 is now booting directly to the loader on the 1200XL with no need to start SDX first.  Thank you

 

Out of curiosity, do you think this is worth also doing on the 600XL and/or 800XL?  Haven't had any issues with them (that I know of), but as I have four extra 74F08s sitting here I'm not opposed to using a couple if it's worthwhile to do so.

[flashjazzcat]

6 minutes ago, x=usr(1536) said:

Out of curiosity, do you think this is worth also doing on the 600XL and/or 800XL?  Haven't had any issues with them (that I know of), but as I have four extra 74F08s sitting here I'm not opposed to using a couple if it's worthwhile to do so.

Unless you discover stability issues on the 600XL/800XL, I would be inclined to leave them alone. It's bad enough that 74LS08 needs to be replaced on problem machines; I have no objection to fitting faster 74 series logic in Ataris, but 74LS was good enough for everything else.

7 minutes ago, x=usr(1536) said:

The 74LS08 has been replaced with a 74F08.  SIDE3 is now booting directly to the loader on the 1200XL with no need to start SDX first.

So that's about a dozen machines I know of (about half a dozen here and half a dozen elsewhere) which needed this 'fix' and responded well to it.

[Beeblebrox]

FYI I replaced my 74LS08 on my 65XE after picking 5 x 74F08 chips up for less than a fiver in the UK (Ebay) https://www.ebay.co.uk/itm/222516648358 

 

?

[Marsupilami]

Hi,
I have the same problem with my 1200xl and my 2 Side3. Any other cartridge will work including the good old Atarimax myide+flash but the Side3. 

Can you tell me which 74F08 to buy? On ebay there are 74F08N and 74F08PC. It may be the same thing but it is beyond my knowledge  

And B.T.W., are we talking about the one with the yellow square in the picture below ?

 

Thanks a lot

Edited April 13, 2023 by Marsupilami

[Beeblebrox]

Both are fine afaik. The end letters aren't that important here. I've used both Iirc. 

 

If your 1200XL stock BTW? 

[Marsupilami]

18 minutes ago, Beeblebrox said:

Both are fine afaik. The end letters aren't that important here. I've used both Iirc. 

 

If your 1200XL stock BTW? 

Thanks @Beeblebrox

No, there is a UAV, a TFHH 512k Ram Expansion, a 800xl mmu, and the Basic RevC+800xl OS ROM REV2 ...so internally it's more a 800xl now. And TFHH also removed the heatsink, installed a linear voltage regulator (four classic 1N diodes) and a new 6800uf Cap.
I have 2 other stock 1200Xl on which i haven't tried the Side3 yet.

 

Just to be sure, can you tell me if it's the one in yellow above that i will need to change ? 

Thanks

Edited April 13, 2023 by Marsupilami

[Beeblebrox]

Cool.Sure. Reason I ask is that it's not always a clear cut case of issues you are experiencing being down to replacing the 74ls08 with a 74f08 if there are lots of other mods/upgrades in place. However, it's worth it given the 74f08 is such a cheap chip to buy.

 

The other thing to check is make sure the voltages are OK and you have a decent power supply. 

 

Yes, that is the chip to replace as you have highlighted. The 74ls08.

 

 

 

 

Edited April 13, 2023 by Beeblebrox

[Ricky Spanish]

How can you tell which 1200XL may be affected, cause I do want the SIDE3. 

Also that cart port extension link in post #1 seems to be a dead-end.

[Beeblebrox]

1 minute ago, Ricky Spanish said:

How can you tell which 1200XL may be affected, cause I do want the SIDE3. 

Also that cart port extension link in post #1 seems to be a dead-end.

Don't think you can tell until you buy and try. Then if any issues you try all the suggested fixes I guess.

[+x=usr(1536)]

4 hours ago, Ricky Spanish said:

How can you tell which 1200XL may be affected, cause I do want the SIDE3.

Best to just swap it and be done with it.  It's literally a 5-minute fix.

4 hours ago, Ricky Spanish said:

Also that cart port extension link in post #1 seems to be a dead-end.

Correct; Dropcheck's on hiatus.  Until she's putting stuff back in production, best bet is to shave / sand / grind the cartridge down so that it'll fit the 1200XL's cartridge port.

[_The Doctor__]

do the chip swap and follow bob1200XL's list of 1200XL fixes

especially the cart port grounding fix etc.

 

@bob1200xl. did you make a complete list of all the touch ups for the 1200XL yet?

[Marsupilami]

10 hours ago, Ricky Spanish said:

How can you tell which 1200XL may be affected, cause I do want the SIDE3. 

Also that cart port extension link in post #1 seems to be a dead-end.

Not really. I've noticed that if you remove the shell, you can insert the Side3 PCB into the 1200xl. I have created a special shell in 3D (to print) that works. I will post this on my site and put a link here.

[flashjazzcat]

I sand down the sides of the shell and then polish them up to make SIDE3 fit in the 1200XL cart tunnel. The whole thing needs to be narrowed by no more than 0.5mm on both sides.

[Marsupilami]

I've just shared a new shell that will fit in another post but just in case : https://www.atarinside.com/blog/index.php/new-shell-for-the-side3-cartridge-and-your-1200xl/

 

[Marsupilami]

On 7/25/2021 at 8:10 PM, flashjazzcat said:

Try replacing 74LS08 with 74F08. This is the exact issue (booting to a black screen) which this modification has fixed on half a dozen machines which have been through my hands.

 

Thanks for the information, my Side3.0 works fine now with my 1200xl and the 74F08PC 👍.

 

I found a modification on the old component, I don't know what it does... Could someone tell me if I should reproduce this on the 74F08? Thanks

 

[Beeblebrox]

6 minutes ago, Marsupilami said:

Thanks for the information, my Side3.0 works fine now with my 1200xl and the 74F08PC 👍.

 

I found a modification on the old component, I don't know what it does... Could someone tell me if I should reproduce this on the 74F08? Thanks

 

That's great it works. Good ol 74F08

 

Personally I'd not replicate the above if all is working.

[_The Doctor__]

The cap was added to take noise off the 2nd comparitors' 1st input. It might not be needed but if you notice any weirdness you can add it back in.

Try a range of very old and new cartridges, including 'blob' on pcb carts.

Edited April 17, 2023 by _The Doctor__

[+kheller2]

1 hour ago, _The Doctor__ said:

The cap was added to take noise off the 2nd comparitors' 1st input. It might not be needed but if you notice any weirdness you can add it back in.

Try a range of very old and new cartridges, including 'blob' on pcb carts.

It's spooky some of the things you know about.