The Naked Atari 800

[rubber_jonnie]

Well, that's annoying. The Postie has just been and dropped off the 4050's I ordered that I later found I didn't need...

No LM 3086 though and I won't be getting any video signal out of the machine without it...

My 600XL has graciously provided an Antic for testing purposes though

@PhilC did you manage to look for an Antic at all? Thanks.

[PhilC]

Well, that's annoying. The Postie has just been and dropped off the 4050's I ordered that I later found I didn't need...

No LM 3086 though and I won't be getting any video signal out of the machine without it...

My 600XL has graciously provided an Antic for testing purposes though

@PhilC did you manage to look for an Antic at all? Thanks.

I've just checked and gave two c021698 chips. I can't remember where they came from but both are used.

[rubber_jonnie]

Well, that's annoying. The Postie has just been and dropped off the 4050's I ordered that I later found I didn't need...

No LM 3086 though and I won't be getting any video signal out of the machine without it...

My 600XL has graciously provided an Antic for testing purposes though

@PhilC did you manage to look for an Antic at all? Thanks.

I've just checked and gave two c021698 chips. I can't remember where they came from but both are used.

Oooh, I'm interested, if you could let me know what you want for one (or both) I'm sure we can come to an agreement

[rubber_jonnie]

Well, I borrowed the Antic from my 600XL just so I had a complete CPU board for testing as I wanted to check power, clocks and reset (PCR).

Power and reset were fine, but no clock. The 3.5795Mhz crystal was missing when I got the board, and that I'd already replaced, but I didn't spot T104 was missing, a 470R resistor. That I replaced easily and after that I had the 1.78Mhz clock at the CPU.

So the PCR checks all complete my attention turned to the address lines, but they were all dead. I had considered the CPU I installed was bad, so I swapped it for another and suddenly the address lines sprang to life

Here you can see the clock in yellow and A1 in blue:

IMG20251207122143.jpg (252.51 KiB) Viewed 148 times

And I now get a black screen, but it's in PAL at least:

IMG20251207122151.jpg (238.73 KiB) Viewed 148 times

So definite progress and looking very positive.

I had considered hooking up a speaker to see if I could hear key clicks, however the missing LM3086 (Oh please come tomorrow!!!) plays a part in both audio and video, so I really need that now before I can do much more in the way of diagnosis.

Very happy with today's diagnosis, fingers crossed I'll have a lot more to go on once the missing IC arrives. Sadly the 600XL doesn't use one, same for the other XL's and XE's. I could steal one from my 400 or 800, but they are such a pain to strip down I'd rather wait!

Hopefully good news soon.

[rubber_jonnie]

So it seems that the keycaps from a Dragon 32 with Stackpole switches fit on the Stackpole switched Atari 800 keyboard that I have for the naked 800, so I may borrow them for testing. I may see if I can find a different keyboard for the Dragon as it's current Stackpole keyboard isn't the best despite a ton of maintenance. I have heard the Hi Tek keyboards are way better so I'll see if I can find one and then the Dragon gets an update

The 800 keyboard does need some maintenance though, as some of the plungers have cracks at the corners, which I'm sure a spot of superglue can fix. Need to dig out the Dragon next.

Interestingly the my complete 800 has a membrane keyboard and not Stackpole.

As for the naked 800, I fitted some temporary RESET, OPTION, SELECT & START switches at the weekend:

IMG_20251208_094814.jpg (320.33 KiB) Viewed 133 times

Not perfect but will be enough for testing and troubleshooting.

[rubber_jonnie]

Well, disappointing, no post at all today so I'm still short an LM3086.

On a positive note I did find a Dragon 32 Hi Tek keyboard at a reasonable price, so hopefully I can replace the crappy Stackpole in my Dragon and simultaneously get some keys for the naked A800.

[rubber_jonnie]

And still no LM3086, and I ordered 9 days ago from a trusted supplier

Really rather disappointing.

[HigashiJun]

And still no LM3086, and I ordered 9 days ago from a trusted supplier

Really rather disappointing.

I understand your frustration...

[rubber_jonnie]

And still no LM3086, and I ordered 9 days ago from a trusted supplier

Really rather disappointing.

I understand your frustration...

I'm hoping it's just a delay due to Christmas deliveries, but very annoying especially since the Hi Tek Dragon 32 keyboard I bought much later arrived today.

[rubber_jonnie]

Having received the Dragon 32 keyboard, I now have a set of keys that will work with the bare keyboard I have for the naked Atari.

However I was hoping the plungers from the Dragon keyboard would work with the Atari since most of the Atari plungers do have some cracks in the corner but the Dragons are slightly thicker and are all good.

Sadly the plungers are not compatible so it'c come down to this:

IMG20251211134539.jpg (306.55 KiB) Viewed 54 times

Yep, it's Stackpole-pocalypse...

It turns out the screws that go through the PCB into the plastics are not the only thing holding it all in place. Every last switch has to be de-soldered before the keyboard and PCB can be split!!!

Then to get the plungers out you have to poke 2 tabs from the underneath!!! At least it's all apart no and I can properly inspect the switch leaf springs for damage, next I need to find a suitable glue to try and repair the plunger corners as superglue didn't cut it.

Worse case scenario they will work without repairs, but I'd like to try and fix them first.