MiSTer FPGA Forum

I will get a second original MemCard in the next days so I can test with two real cards and two controllers.

Question, what does the Multitap Option?

Multitap option in OSD will simulate a multitap in port 1 with 4 digital controllers.

It's not of any use for SNAC.

this is the interior of my cards，i think they are both real oringinal cards，but they cant work on the lasted core.

In contrast ，my friends’ fortified cards work well on lasted psx core.

so maybe it is the issue of cards‘ compatibility.

You can try with the latest unstable build (when it's done) or the test-build in discord.

I added 2 register stages to all SNAC input pins in case metastability was the issue.

FPGAzumSpass wrote: ↑Sat Jul 16, 2022 10:26 am You can try with the latest unstable build (when it's done) or the test-build in discord.

I added 2 register stages to all SNAC input pins in case metastability was the issue.

Tested, the same, two memory cards working, and 2 not working......metastability seens not be the issue.

cloudyng44 wrote: ↑Thu Jul 14, 2022 9:07 am I tested every psx core between date 2022-6-18 and 2022-6-26
I found the problem first appeared on 2022-6-20 core

at last I solve the problem by editing the file psx.sv and use quartus to generate the rbf file again.open the psx.sv file and I edited the line 406 code
‘TURBO’ back to ‘Data Cache’

then i use the edited rbf，i can find the physical memcards again.

Tested also this modified core, almost the same, two working, 1 not working and 1 only show the content of the memory card but no save/load, if i try to do something with this card, nothing´s happendonly show content.

The not working memory cards don´t do nothing, but in this modifeied core, show something.

The memory cards that work, when you insert/remove them in the bios for example, update themselves with the simple fact of inserting or removing them. those that do not work, do nothing, in fact, they do not detect that you are inserting or removing a memory card, they are not updated and if I force to insert/remove one that works so that they are updated, only the one that works is updated, the one that does not work is as if it does not exist.

Perhaps it is a failure of the memory card itself, depending on whether they are manufactured, they work or not, as soon as I can upload a photo of the interior of the ones that do work for me.

FPGAzumSpass wrote: ↑Sat Jul 16, 2022 10:26 am You can try with the latest unstable build (when it's done) or the test-build in discord.

I added 2 register stages to all SNAC input pins in case metastability was the issue.

thanks

I tried it just now and found an interesting thing：

i have 2 controllers：one is oringinal dualshock，the other is hori

if i only insert the dualshock controller（which has rumble system ，model：scph 1200） to port 1，the cards works but unstable（some saves lost sometimes）

if i only insert the hori controller to port 1，the cards works and stable.

if i insert these two controllers to port1 and port2 at the same time，the cards can’t work.

My two cards, both working fine at the same time with the PSX Memcard Manager.
I use an Dualshock2 SCPH-10010 Controller on a PS1 Front Panel which is connected using the FFC cable to a selfmade (not from me) PSX-SNAC-PCB.
The whole Adapter is used either with an Analog IO Board 6.1 or a Digital IO Board 1.2.
The PCB is electrically based on blue212's PSX-SNAC Adapter Schema but contains a DC-DC Step-Up for Rumble.

this photos are from inside my two working memory cards.

I am using a playstation 2 original dualschock controller, i wil test with original ps1 digital only controller and ps1 analog controller.

cloudyng44 wrote: ↑Sat Jul 16, 2022 2:45 pm I tried it just now and found an interesting thing：

i have 2 controllers：one is oringinal dualshock，the other is hori

if i only insert the dualshock controller（which has rumble system ，model：scph 1200） to port 1，the cards works but unstable（some saves lost sometimes）

if i only insert the hori controller to port 1，the cards works and stable.

if i insert these two controllers to port1 and port2 at the same time，the cards can’t work.

Can you please post a full image of your adapter board?

Blue1 checked many games with many different controller and memcard combinations now and so far hasn't found anything.

Maybe a picture could show if there are some issues.

here you are

Which IO Board do you use?

cloudyng44 wrote: ↑Sun Jul 10, 2022 2:44 am I used this design of snac https://github.com/blue212/SNAC-PSX

I assumed you use the design from Blue1 and then you use something completly different...
That doesn't really help finding the root cause.

Anyway: one possibility is the cable connecting the board.
There have been reports about cables being a problem if they are not VERY short. Please try that if you can.

FPGAzumSpass wrote: ↑Tue Jul 19, 2022 1:51 pm

cloudyng44 wrote: ↑Sun Jul 10, 2022 2:44 am I used this design of snac https://github.com/blue212/SNAC-PSX

I assumed you use the design from Blue1 and then you use something completly different...
That doesn't really help finding the root cause.

Anyway: one possibility is the cable connecting the board.
There have been reports about cables being a problem if they are not VERY short. Please try that if you can.

yes，you are right.today I plug my adapter to snac（user io）directly and i solved the problem.so the problem is caused by the length of the cable between snac and user io.（ps：The cable i used is only 0.5 meter but it still can not work maybe i want a 0.1 meter cable？），Hope next core u can corret the cable length problem，thank u.

How should i address the cable length problem within the core?

Please close the github issue if it works now.

Cable length affects MT32-Pi as well. Good job researching everything everyone. For anyone that has a SNAX from misteraddons.com this is the cable I used and memory cards work fine for me:

https://www.amazon.com/dp/B00NTR1D8E

My cable is a simple USB3 20cm male to female cable which works with all my SNAC Adapters.

FPGAzumSpass wrote: ↑Wed Jul 20, 2022 7:23 am How should i address the cable length problem within the core?

Please close the github issue if it works now.

Not an FPGA developer, but I would imagine loosening receive timings somewhat could potentially work around the problem. It's probably a little too tightly coupled now, so that a longer cable takes too long for the signal to propagate both ways.

I guess it could also be a resistance or capacitance issue, where the longer cable has a little more of both. That sort of thing is way out of my depth, however. I know that real electronics engineers know how to fix that sort of thing, but I barely even know what a resistor is.

Blue1 indeed provided a fix for it in the core now.

It's kind of a workaround: the longer cable leads to glitches in the ack signal which are now filtered in the FPGA by only reacting when the signal stays low for longer.

So you cannot get rid of analog effects outside of the FPGA, but you can mitigate it.