Internal ACSI2STM

[ojanhk]

I’ve been trying to mount an ACSI2STM internally in a MegaSTE a while back without too much success. 
Basically I’ve mounted a socket and an SD card connector on one side of a perfboard and a connector to the Internal ACSI on the other side.

 

The power is delivered through the ACSI connector from the motherboard (PSU Fully recapped less than 6 months ago), and this was the cause of my initial issues. Adding a capacitor on the perfboard close to the STM32 finally got it to boot. 
 

Still it doesn’t work properly and I will look deeper with logic analyzer and scope over the week-end, but if someone here has a clue of what could be wrong, it could be a real time saver.

 

Symptoms:

- Machine (TOS 2.06FR) Boots and display PP driver initial screen where you can choose to swap C with another disk.

- At the end of the countdown, I immediately get 3 bombs.

- Warm reset will give 4 bombs.

- Bypassing Hard disk boot and using PPDRIVER software, I can format the drive properly.

- I noticed the format screen shows proper disk space used but total is « NEG » and percentage is garbled.

- Installing the boot loader hangs before display hard disk lists.

- using the « manual » driver Us10r says it doesn’t detect any hard disk and quits. 
- Using HDDRIVER doesn’t even recognize any device at all.

 

Tests done so far: 

- Checked power: steady and clean 5V.

- Checked all solders: everything looks clean even with a magnifier. 
- Tried to power via USB after disconnecting from internal power, same results.

- Tried different SD cards: same issue. 

- Removed the internal ACSI2STM, put back jumpers on first 16 pins of internal ACSI connector and tried with external ACSI2STM :

       - It works perfectly, boots fines, Boot Loader installation detects hard drive properly.

       - Format screen of PPDRIVER software shows proper disk space and percentage.

 

So, it doesn’t seem to be random as it always boot up to the same screen and crashes exactly at the same moment. The most obvious issue would be a bad solder or a short, but in that case how would it go as far as listing the drives and displaying PPDriver’s banner ?

 

 

[ParanoidLittleMan]

First question:  do you have internal ACSI-SCSI adapter at all ?  Because you wrote : " Removed the internal ACSI2STM" - I guess that you meant under it actually original internal ACSI2SCSI ...

Now, if it works well connected to external ACSI port, all you need is to find all those lines on external connector inside, and connect all properly. Then it will work fine.

Don't need logic analyzer and like. Ohmmeter and schematic is what you need. There are multiple GND lines on ACSI conn. , so need to find less than 19 signals.

Errors are for sure because you connected something to wrong place.

[ojanhk]

Hi Peter, 

Thanks for your answer.

No I don’t use internal ACSI-SCSI adapter in this one. Actually I directly plug the ACSI2STM on the internal connector. 
When I want to test with external ACSI2STM, I remove internal one, install jumper on first 16 pins to make sure external connector si properly connected. 
Thanks for your advice, I will do testing between external connector and internal ACSI2STM to look for wrong connection(s). 
 

[ParanoidLittleMan]

What ? There is version of ACSI2STM what goes to internal connector ?

Photo please.

[ojanhk]

Actually it doesn’t exist yet, that’s exactly what I’m working on?

[ParanoidLittleMan]

OK. I'm sure you will solve it .

 

[masteries]

44 minutes ago, ojanhk said:

Actually it doesn’t exist yet, that’s exactly what I’m working on?

 

Due to you are one of my customers, 

 

Are you using this same unit externally? Or you are using the one you bought externally?

 

The hand made version you exposed there lacks signal shielding, despite wires length are short, with no shielding, these are more susceptible to any induced noise from the motherboard.

 

Now the device is inside the case, and these are fast signaling 5 volts based machines; there are a lot of EMC near the motherboard, any of the wires can act as an antenna and receive a signal that corrupts the data.

 

 

Edited January 6, 2022 by masteries

[ojanhk]

Hi masteries, 

yes I use the same unit internally and externally, I’ve socketed both so I can swap the stm32. 
I agree with you, I was suspecting EMC issues, but the fact that it always crashes exactly at the same moment and that formatting is working well each times makes me think it might be different. I would expect EMC related issues to be more random, but I’m no electronic expert, so maybe it’s EMC. I can try to shield it.

 

[+DarkLord]

Just to point out, Lotharek sells a internal adapter for the Mega STe and STacy:

 

https://lotharek.pl/productdetail.php?id=49

 

Get that, move your device up into the lid of the hard drive bay cover and

mount it there (distancing it from the motherboard).

 

EMC problems solved. 

 

 

 

[ojanhk]

Hi Darklord, yes clearly the internal UltraSatan is the most straightforward solution for internal storage in the MegaSTE. I have one in an other machine and it’s really great, I 3D printed a support to install it in the lid and it’s working flawlessly. 
But it’s not cheap and that’s why I’m experimenting with the ACSI2STM, just for fun. 
 

Actually, my first try with the internal ACSI2STM was with a ribbon cable to the connector in order to move it away from the motherboard, but it was even worse in terms of stability. I suspect the non buffered output doesn’t really like the ribbon cable. 

[FastRobPlus]

FWIW I've been trying to get an ASCI2STM built for a long while. I can't compile the source from GitHub without getting some mismatched libraries-related issues.  I'd kill for a precompiled image I could just flash to the bluepill with the STLink.

[snarkdluG]

17 minutes ago, FastRobPlus said:

FWIW I've been trying to get an ASCI2STM built for a long while. I can't compile the source from GitHub without getting some mismatched libraries-related issues.  I'd kill for a precompiled image I could just flash to the bluepill with the STLink.

Don't kill yourself. You got PM.

[FastRobPlus]

Well it wasn't myself I was volunteering to kill ;-).

Either way, thanks a lot for directing me back to the GitHub. It's been ages since I tried this and didn't notice that a binary had been added to the repository! I'll give this a try right away^*

 

 

 

*as soon as I verify I've got any STM32s.

[snarkdluG]

9 minutes ago, FastRobPlus said:

Well it wasn't myself I was volunteering to kill ;-).

Either way, thanks a lot for directing me back to the GitHub. It's been ages since I tried this and didn't notice that a binary had been added to the repository! I'll give this a try right away^*

 

 

 

*as soon as I verify I've got any STM32s.

 Nah. I did a fork from the official github and did a binary. I also did a new PCB.

[FastRobPlus]

Oh so this is your design?  I think it's a great device for ST collectors. I actually saw somebody in using one over the weekend that reminded me I'd started down the path of trying to install one internally on my Stacy to replace the 30+ year old spinning platter drive. That person gave me a an original (non-fm) 520ST so now I guess I have two candidates for this device!

[+DarkLord]

4 hours ago, FastRobPlus said:

Well it wasn't myself I was volunteering to kill ;-).

 

Almost choked on my tea when I read this.  

 

Good luck with your project!

 

[cbelcher]

On 1/6/2022 at 5:29 PM, snarkdluG said:

 Nah. I did a fork from the official github and did a binary. I also did a new PCB.

Could you point me to your fork please?

[ojanhk]

Past few months have pretty busy with "real work", but I finally managed to get the internal ACSI2STM woking on the MegaSTE.  I restarted from scratch a few weeks back going directly for a PCB and apart from a small bodge wire, it works perfectly fine !

 

It uses 5v from the internal ACSI connector, so fully plug-and play ? 

The PCB can handle both the "standard" ACSI2STM, here running on a real STM32F103C8 and also @masteries version which is based on a different wiring, just need to solder a few jumpers (you still need to get the ACSI2STM from @masteries though):

 

I'll try to get an internal version for Mega ST in the coming weeks and port the original software to the LONGAN Nano, an STM32 clone with integrated MicroSD.

 

 

[Paul Westphal]

Friggon' nice work OJ!

[ojanhk]

KiCAD files and gerber are now available: https://github.com/olivierjan/ACSI2STM-MSTE

[Smokeless Joe]

Thanks!  This looks really cool!

[Smokeless Joe]

The image and BOM on your GitHub page refer to a 10uF radial capacitor (see red arrow on attached image), but the Gerbers and the images of the boards you posted last Saturday don't have it.  Is it no longer needed?

 

I'm hoping to make one of these myself (eventually) and just want to make sure I have everything straight.  Thanks!

 

 

Edited April 13, 2022 by Smokeless Joe

[ojanhk]

The pictures I posted were from a first batch of PCB which is working but have small defect. The version on GitHub is a slightly revised version adding a second capacitor as per recommendation from ACSI2STM documentation.

I guess you can build the board without the capacitor as the first version didn't have it and it was working fine.

 

Edited April 13, 2022 by ojanhk

[Smokeless Joe]

I see the source of my confusion! 

 

When I download everything from your GitHub HERE, and look in the Output folder, the .ZIP file gives a board that only has C1 and is missing C2:

 

But the individual .GBR and .DRL files in the Output folder (NOT in the .ZIP file) give a different board, which includes both C1 and C2:

 

So... which board do you recommend?

Edited April 14, 2022 by Smokeless Joe

[ojanhk]

Ok, let me clean the GitHub repository, it seems I have mixed files from a previous version. 
the version with only one capacitor is an old one and shouldn’t be used (unless you want to add a bodge wire). I’ll clean the repository tomorrow morning (Paris time).