@agranlund Thanks!
I'm having issues programming the ROM. Sending the file does nothing in CoolTerm, the Pico light never flashes. Tera Term 4 seemingly sends something up to a few KB but no lights flash and ultimately it stalls. Since I get the programmer menu and can interact with it, I'm not sure what the issue is...
Edit:
I reflowed everything on the simm but no difference.
The chips are SST39LF802C-55-4C-EKE if it makes any difference.
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At this time it is unfortunately not possible to white list users when your IP changes constantly.
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At this time it is unfortunately not possible to white list users when your IP changes constantly.
You may inadvertently get banned because a previous attack may have used the IP you are now on.
So I suggest people only use fixed IP address devices until I can think of a solution for this problem!
Atarian Computing's Raven Build
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Atarian Computing
- Posts: 539
- Joined: Tue Aug 22, 2017 4:27 am
Re: Atarian Computing's Raven Build
I'm using the same chips here.
Does it identify it ok when you run the i command?
Try running e for erase before programming and see if that helps, in case there's some kind of code issue making that required before programming it for the first time (it's not supposed to be required)
These are my settings in CoolTerm:
Does it identify it ok when you run the i command?
- Screenshot 2025-10-14 at 16.48.23.png (95.17 KiB) Viewed 280 times
These are my settings in CoolTerm:
| Header 1 | Header 2 | Header 3 |
|---|---|---|
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Atarian Computing
- Posts: 539
- Joined: Tue Aug 22, 2017 4:27 am
Re: Atarian Computing's Raven Build
@agranlund
It doesn't detect it...
I've reflown the programmer, double-checked everything. I've duplicated your settings. Tried various cables and speeds. No dice...
Edit: SIMM pcb should be fine. It's the correct thickness and two builders here are successfully using them.
Edit2: Erasing just instantly says "Erase...Done"
It doesn't detect it...
- Screenshot 2025-10-14 175740.png (50.31 KiB) Viewed 275 times
Edit: SIMM pcb should be fine. It's the correct thickness and two builders here are successfully using them.
Edit2: Erasing just instantly says "Erase...Done"
Re: Atarian Computing's Raven Build
It's not much but at least we can conclude the issue is, at least right now, somewhere between the pico and one or both of the SST chips.
Since communication is somehow failing in the chip identification sequence we can likely assume erase/program wont work either at this point.
If it was me I think I would suspect and double check the rom chips since they have the finest pitch, and the small 74LVC2G08 as well.
For shorts and no-connects and that the chips are in the correct orientation.
Since the programmer itself is all through-hole stuff the only thing I can think of that I would check is that the 74HC273's aren't in the wrong orientation.
Since communication is somehow failing in the chip identification sequence we can likely assume erase/program wont work either at this point.
If it was me I think I would suspect and double check the rom chips since they have the finest pitch, and the small 74LVC2G08 as well.
For shorts and no-connects and that the chips are in the correct orientation.
Since the programmer itself is all through-hole stuff the only thing I can think of that I would check is that the 74HC273's aren't in the wrong orientation.
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Atarian Computing
- Posts: 539
- Joined: Tue Aug 22, 2017 4:27 am
Re: Atarian Computing's Raven Build
@agranlund Thanks. Yes logically it's the rom chips or the 74 chip. I'll have a go at redoing them tomorrow. I ordered some more so I can have an extra ROM simm for convenience. Should get them as soon as Friday. Will let you know.
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Atarian Computing
- Posts: 539
- Joined: Tue Aug 22, 2017 4:27 am
Re: Atarian Computing's Raven Build
@agranlund
I removed the rom chips and put them back in. We have some improvement but now the programmer seems flaky or maybe I don't know how it should behave.
Prior to today, the button on the programmer reset it and the menu reappeared in the terminal. This time it does nothing. Also, getting it to actually work on the terminal took some effort for some reason.
The rom chips are now recognized
I'm able to send a file and the Pico actually flashes but at times the light goes off and nothing happens.
When I read back the rom it seems to give gibberish. Is this a terminal encoding issue or something else.
Either I'm shit at soldering smd or something wonky is going on. I have a microscope and there are no solder bridges. Only thing it could be is that some legs are floating and not making contact but I've tried to make sure everything is in place. Here are a couple of screeshots:
Config space is 0 bytes which seems wrong
I tried slower speeds as well.
I removed the rom chips and put them back in. We have some improvement but now the programmer seems flaky or maybe I don't know how it should behave.
Prior to today, the button on the programmer reset it and the menu reappeared in the terminal. This time it does nothing. Also, getting it to actually work on the terminal took some effort for some reason.
The rom chips are now recognized
I'm able to send a file and the Pico actually flashes but at times the light goes off and nothing happens.
When I read back the rom it seems to give gibberish. Is this a terminal encoding issue or something else.
Either I'm shit at soldering smd or something wonky is going on. I have a microscope and there are no solder bridges. Only thing it could be is that some legs are floating and not making contact but I've tried to make sure everything is in place. Here are a couple of screeshots:
- Screenshot 2025-10-16 102050.png (87.02 KiB) Viewed 171 times
- Screenshot 2025-10-16 103806.png (139.61 KiB) Viewed 171 times
- Screenshot 2025-10-16 103817.png (73.68 KiB) Viewed 171 times
I tried slower speeds as well.
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Atarian Computing
- Posts: 539
- Joined: Tue Aug 22, 2017 4:27 am
Re: Atarian Computing's Raven Build
Ok, apparently the gibberish is fine as I compared the dump to the binary. So looks like my rom issues are resolved now.
Now, to get some output on the terminal... I guess a null-modem cable won't work?
Now, to get some output on the terminal... I guess a null-modem cable won't work?
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Atarian Computing
- Posts: 539
- Joined: Tue Aug 22, 2017 4:27 am
Re: Atarian Computing's Raven Build
Btw, I have this cable: https://www.aliexpress.com/item/3302936 ... 1802wy3fkB
Re: Atarian Computing's Raven Build
The dump of the erased rom looks ok, it should be completely filled with ff when blank.
Likewise, the programmed one looks good too - at least the section you’re viewing starting at $0 (early vector table)
My biggest concern would be 114688 bytes written (unless that was the size of the rom image you wrote?)
Oh and randomly(?) stopping to respond while programming too as you mentioned.
The button, as far as i remember but i could be wrong, just cuts the power to the pico when held down.
So a kind of hard-reset rather than having to unplug/plug the usb cable when going into pico firmware programming mode etc.
Hard to say why windows/terminal program takes issue with that.
Likewise, the programmed one looks good too - at least the section you’re viewing starting at $0 (early vector table)
My biggest concern would be 114688 bytes written (unless that was the size of the rom image you wrote?)
Oh and randomly(?) stopping to respond while programming too as you mentioned.
The button, as far as i remember but i could be wrong, just cuts the power to the pico when held down.
So a kind of hard-reset rather than having to unplug/plug the usb cable when going into pico firmware programming mode etc.
Hard to say why windows/terminal program takes issue with that.
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Atarian Computing
- Posts: 539
- Joined: Tue Aug 22, 2017 4:27 am
Re: Atarian Computing's Raven Build
Yeah, I'm using the rom_mon.bin. I had to reprogram a couple of times as the bytes didn't match on columns 2,6,A, & E. Real weird stuff... You can see it below. 1st is after erasing. 2nd is a failed flash. 3rd is successful.agranlund wrote: Thu Oct 16, 2025 12:10 pm The dump of the erased rom looks ok, it should be completely filled with ff when blank.
Likewise, the programmed one looks good too - at least the section you’re viewing starting at $0 (early vector table)
My biggest concern would be 114688 bytes written (unless that was the size of the rom image you wrote?)
Oh and randomly(?) stopping to respond while programming too as you mentioned.
The button, as far as i remember but i could be wrong, just cuts the power to the pico when held down.
So a kind of hard-reset rather than having to unplug/plug the usb cable when going into pico firmware programming mode etc.
Hard to say why windows/terminal program takes issue with that.
- Screenshot 2025-10-16 142524.png (48.34 KiB) Viewed 155 times
- Screenshot 2025-10-16 142420.png (60.75 KiB) Viewed 155 times
- Screenshot 2025-10-16 142405.png (58.43 KiB) Viewed 155 times
I have no serial output right now.
I've connected the usb-serial cable to the Raven with what I assume to be a null-modem cable. Does it have to be null-modem? If not, I need a gender changer as the usb cable is male.
I'm connecting at 115200bps 8N1 to the lower left port on the Raven.
I only have the ROM simm.
None of the chips are even getting warm, should they?