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

[szalay_1]

The results. Thanks to Trimesh!

Ram_Test_On-8M-1.jpg

Ram_Test_On-8M-2.jpg

Ram_Test_On-8M-0.jpg

Ramtest.8M.PSX.2.EZ.jpg

[Bluesfire]

Did some hunting around and can't seem to find a source on these RAM chips whatsoever these days. Anyone have a source?

[nocash]

Sounds as if you didn't read this, http://www.psxdev.net/forum/viewtopic.php?p=5457#p5457
Or is it some google-that-for-me-but-I-won't-buy-used-parts request?

[Bluesfire]

I read through the entire thread and searched for both KM48V2104AJ_6 and KM48V2104BS-6 chips, but wasn't able to locate any outside of Digipart, where they were all listed as "Inquiry only". I'm happy to buy used parts, but wasn't able to locate any for sale at the time.

I've now realized my mistake in searching for the chips specifically, and not looking for the KMM466F213BS1-L6 SODIMM sticks that have the KM48V2104BS-6 chips on them. I plan on ordering some soon to do this mod for myself.

Apologies for asking without doing more of a search first. I made this post after joining and browsing the forums for a bit, and was just excited about these mods I hadn't heard of yet. There is a wealth of information here I am very thankful for.

[nocash]

Okay, I've never tried to buy old chips myself, but there seem to be tons of sites offering that stuff. I don't know how reliable they are, but "can't find" is a bit of a surprise... if that happens, I would try a different search engine, and be sure to include world-wide search results, including english-language webpages Doing a quick search I can find 24 pieces for $0.00 (but the order total must be at least $99, which seems impossible, so you are perhaps better off desoldering them from old PCBs if you can get those).

[ragen-fio]

A very fun project to spend a Sunday afternoon on, with the constant thrill that the RAMs wouldn't work because I didn't have a chance to test them before desoldering them, but luckily it went well on the first try. The console works perfectly but in the next few days I will check the RAM with the appropriate test.

Thanks to the creator of this mod and everyone involved.

I still have to clean the flux

Ciao!

[szalay_1]

"didn't have a chance to test them before desoldering them"
Yes same as here, bought from eBay and no other choice just soldering them... and waiting with great excitement to see if it works or not. We're lucky !
It is also very reassuring after a ram test that all 8 megabytes are available!
BTW: You have nice job !

[ragen-fio]

"didn't have a chance to test them before desoldering them"
Yes same as here, bought from eBay and no other choice just soldering them... and waiting with great excitement to see if it works or not. We're lucky !
It is also very reassuring after a ram test that all 8 megabytes are available!
BTW: You have nice job !

Thank you! I don't solder very often because it's a hobby and I do a different kind of job in life, but I like to keep myself in training.

And yeah, also I don't want to push my luck by modding another one before having found a laptop with which to test the RAM, but anyway I wouldn't even know what to do with another PS1 with so much memory...

Could anyone tell me if it is possible to load the RAM Test in the zip file via PSXSERIAL? I messed around with it a bit a few years ago (I have to remember where I put the cable I made back then) and I remember it working very well. These days I'm not at home and I don't have the chance to try.

[szalay_1]

You ask our @danhans42, he can help!

[ragen-fio]

I'll start by saying that I'm probably doing something wrong so please have mercy on me. I tried to launch the RAM Test (the MAIN.EXE file in the zip attached to the post in the first page) both with PSXSERIAL with the CD and with NOPS via a cartridge with UNIROM. In both cases with little success. With PSXSERIAL the data sending is successful but the status hang on the message "Receiving data from PC", while with NOPS, the data sending is successful here too, I have an error message from UNIROM.

I have also tried other .EXEs and they all work correctly with both PSXSERIAL and NOPS.

Any help is very welcome.

[Administrator]

It's very likely that the memory is being trashed. Check the address size and offsets. When Trimesh was developing and testing the program it was loaded by another method and not a serial uploader.

[ragen-fio]

It's very likely that the memory is being trashed. Check the address size and offsets. When Trimesh was developing and testing the program it was loaded by another method and not a serial uploader.

Thanks for the reply! As I thought there was something wrong, but I preferred to choose the method that was simplest for me first. I'll have to move to another way.

[szalay_1]

I'm used old method to upload ramtest.ps-exe
via ISA card PSX_Comm Link & caetla.rom with PSEXE.COM and PSXloader.exe

how are you sending via serial?
If you use unirom, just add /m to the commandline to see the console output?

i will send you via PM the ramtest.ps-exe any try it ok ?

[ragen-fio]

how are you sending via serial?
If you use unirom, just add /m to the commandline to see the console output?

Sorry for the late reply. I use a normal FT232RL USB-Serial adapter installed inside the console for loading .EXE files and as mentioned, both with PSXSERIAL and NOPS everything works normally except with the RAM Test. But as I was told by a previous answer the problem could be in the serial loading.

If you use unirom, just add /m to the commandline to see the console output?

I will try adding the /m command with UNIROM.

i will send you via PM the ramtest.ps-exe any try it ok ?

Thank you! I'll give it a try.

[ragen-fio]

I think it worked with the executable that szalay_1 sent me and I thank you again.
I don't know if the test times are regular, in my case about 40 seconds pass between the initial screen and the completion screen, but I have launched the test many times and it has always been successful.

[szalay_1]

Sure Yes! the ram test successfully done
You've Tested 8M of ram PSX >> kool !
Good to know i'm no alone.....

[ragen-fio]

Maybe this is the first time a game use the additional RAM on real hardware?

However, I am satisfied with the result and I would also like to try some mods for GT2.

Ciao!

[FuzzyWuggzy]

Are boards with CXD8530* CPUs still out of the question? I read the pdf and realise that the revisions have differing CAS/WE line configurations, but it says that it should still be possible. As PS1's with PU-8 (rarely PU-7) boards are the easiest to identify in the wild I was thinking it might be worth while. I'd be willing to test any developments but I can't offer more, I'm simply a technician that wants to improve my programming skills in the future, not a hardware engineer.

Thank you in advance.

[ragen-fio]

A couple of months ago, following an indication in an old message of Trimesh, I also tried upgrading the video RAM by piggybacking two SGRAM chips and connecting the CS pin to the corresponding MCS1 pin of the GPU. It is also interesting to note that most motherboards have a convenient pad on which you can solder the wire/resistor without having to mess with the GPU pins directly. (This method is identical to the RAM upgrade on XBOX V1.6.)
I didn't expect to get anything obviously, but I was really curious to try it, and the fact that the console works normally without problems is already a positive result, but I didn't do any further tests because the lack of time and I'm a novice with software.

The modification itself required a bit of work because I had to straighten all the pins of the chip to get them as close as possible to the underlying ones to solder them and the danger of breaking someone was always around the corner, so it's not my best soldering job and if I had to do it again I would do it differently.

Ciao!