[Hardware Mod] 8MB in (PU-18) Retail PSX

[KellyDevPs1]

Just did the mod but am a total noob and dont have a way to get data into my ps1 besides burning discs and was wondering what the easiest & the best way would be to check if the 8mb mod worked that way? Coming from a Hardware hobby background not sure what would be the next steps haha.

[TriMesh]

Unfortunately, the memory test was designed to output everything to the debug console - as a result, you need some way of seeing the console output (either a serial cable or something like a reflashed Action Replay cart) in order to use it. Since it's a mod that's really only useful to people doing development, this didn't seem like much of a limitation.

It would be possible in theory to write a stand-alone version, but it would be a much more complex program because it would have to interact with the console and contain the code to handle the screen to display the results of the test.

On a practical level, if the console boots OK post modification then it's almost certainly working correctly.

[szalay_1]

@ KellyDevPs1
Read back this topic again, I got a rewritten ramtest built , what i can run via serial or usual "cheat cartridge" to show the result on screen

[nedrysoft]

I am about working on something and part of it is the 8MB RAM upgrade, there will be an FPGA involved in this but for the moment I created a set of PCB's to allow me to easily flip back to a RAM only configuration without the FPGA and buffers connected.

I'll upload the board set sometime this week to GitHub, there's actually currently 3 different sets of boards involved here, there's some breakout boards that replace each RAM chip on the board to a 1.27mm SMD header, those then currently mate with an intermediate board that you can see the bottom of that has a 1.27mm SMD connector on the other side that breaks out all the data, address and control signals to a single 1.27mm SMD connector and then finally there's the top board which contains the ram and a jumper (that's labelled incorrectly, default should be on 2MB) to select 2 or 8 MB and a load of test pads for probing that I didn't actually need since it worked without issue.

There's a single jumper wire on the rear of the PCB to connect the A10 line from the CPU to an NC on one of the RAM chips on the motherboard which I then pass on up to, the mod can be completely reversed, no track cutting required.

There's also a mechanical alignment board that I used to make sure the two sets of four 1.27mm connectors for the RAM on the motherboard and the intermediate board are aligned correctly and can be connected together, I have one which doesn't have connectors soldered and the other which does which allows me to align both sets.

Since doing this as I need more signals from elsewhere on the motherboard, I took a PU-18 board and removed every single component and then produced high resolution scans of the top and bottom, I'll also upload those to GitHub this week.

I'm waiting on another board prototype to arrive and once I have that working and I then do the design that melds that functionality along with the FPGA.

[TheBrooster]

@ragen-fio @szalay_1 Any chance you could PM me a copy of the ramtest.ps-exe, please?

[szalay_1]

check your PM

[Jackhead]

Im still looking for some RAMs that i can use. Anyone have a source where to find atm?

[nedrysoft]

Im still looking for some RAMs that i can use. Anyone have a source where to find atm?

Depends where you are in the world, the best bet is to harvest them from a simm.

Currently on eBay there’s these that have the correct RAM chips but the seller seems to only ship to the US.

https://www.ebay.co.uk/itm/133931568848 ... media=COPY

There have been other sellers with modules with the correct RAM on them, but I did a quick search and couldn’t see any currently listed, but I didn’t really spend long looking.

If you do a deep scour using various search terms like 16MB, 32MB, EDO, Samsung, 3.3V, etc and go through each result looking at the images you might get lucky, a word of warning I have seen ones mislabelled as 3.3V when they’re actually 5V.

[tunertom]

I have attached the fixed 8MB Ramtest package zip to this post, just incase anyone else has been searching for it as long as I have!

Fixed 8MB RamTest set.zip

[gwald]

Could someone please, with a 8MB mod mind testing my PSX.EXE?
Basically, it's a .cpe program from the SDK which does the MIME animation, converted to a psx.exe with the media appended to it in the correct 8MB memory locations.
viewtopic.php?f=76&t=4238

Normally, the dev kit would send the executable and the media separately, I just made it into a single PSX.EXE RAM rom, I guess.
And it works on most emulators, except for no$psx.

[tunertom]

If anyone is struggling to find a set of the upgraded ram chips, I had to order in bulk - so still have some spare sets..

Based in the UK, can discuss worldwide shipping no problem, I'm just a message away!

[ragen-fio]

Could someone please, with a 8MB mod mind testing my PSX.EXE?
Basically, it's a .cpe program from the SDK which does the MIME animation, converted to a psx.exe with the media appended to it in the correct 8MB memory locations.
viewtopic.php?f=76&t=4238

Normally, the dev kit would send the executable and the media separately, I just made it into a single PSX.EXE RAM rom, I guess.
And it works on most emulators, except for no$psx.

If you're not in a hurry I can try in the next few days. Unfortunately I'm busy with some PS2s to repair in the little free time I have.

[szalay_1]

"Could someone please, with a 8MB mod mind testing my PSX.EXE?"
Yes, me too in a weekend ...

[gwald]

Thanks guys! Great! I'm hopeful, but it's really hacky so I don't expect it to work.

[ragen-fio]

Thanks guys! Great! I'm hopeful, but it's really hacky so I don't expect it to work.

I tried to upload the file via serial, with NOPS, several times but it always gets stuck at about 37%. To be safe I downloaded the file a second time but the result did not change.

[gwald]

Thanks guys! Great! I'm hopeful, but it's really hacky so I don't expect it to work.

I tried to upload the file via serial, with NOPS, several times but it always gets stuck at about 37%. To be safe I downloaded the file a second time but the result did not change.

Ah, thanks for that! HMmmm 37% of the 5.2MB executable would 1.924MB if my math is correct, and linked at 0x80100000 (65KB) would make it very close or over the 2MB RAM, so I guess that answered the question.



I'm not familiar how the RAM is mapped, but hypothetically????? I'm guessing???? nops could be made aware of where not to write and to skip writing into those areas and continue writing data and running the PSX-EXE like normal??

I'm guessing that logic would go here: https://github.com/JonathanDotCel/NOTPS ... ic.cs#L818

Or a new write function for +2MB executables.

TBH I don't understand where the ranges are in RAM.

https://psx-spx.consoledev.net/memorymap/

If the NOPS dev agrees or one of you 8MB users can fork the repo and add that feature in, I can copy his range checks, and use it as error checks in yarexe if real data is written to the BIOS mapped RAM, I just need a list of ranges (in terms 0x80000000 or zero to 8MB) to check.

I package PSX.EXE + assets into a single executable often, I just don't think I'll ever get a 8MB PSX



I'll ask on github via an issue.

[Jackhead]

Finally found some RAM.. Thanks to TriMesh for this great mod and tool!

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[szalay_1]

Thanks guys! Great! I'm hopeful, but it's really hacky so I don't expect it to work.

Same here, used Caetla PSEXE.COM via Comms Link Isa card,
loading forever...

Finally found some RAM.. Thanks to TriMesh for this great mod and tool!

For RAM test you are used the "Main.exe" ?

[Jackhead]

i used the cd image on xstation from the package tunertom post.

[gwald]

Thanks guys! Great! I'm hopeful, but it's really hacky so I don't expect it to work.

Same here, used Caetla PSEXE.COM via Comms Link Isa card,
loading forever...

Thanks