CPS3 NOR Open SIMMs

[BigP_BigP]

I am not sure if anyone here is interested in this type of project, but I was for a few reasons (mainly to get my own CPS3 working with all 6 titles). While looking into them I made a few interesting discoveries that are not widely publicised and may assist anyone looking at taking on this project. This is based on early testing so ill update it when or as I know more.
1. They appear to be 100% compatible with the UltraBios, so you dont need to update your cart again if you already have an UltraBios.
2. The instability issues mentioned on the github appear to stem from the LS148a. This part appears to be to slow to turn off (tDIS) causing the mentioned instability. It can be fixed by using a 74F148 in the same location. I suspect a 74LVC148 would also achieve the same thing but have not tested it. This is important because the 74F is obsolete and difficult to obtain where as the 74LVC is still in production.

 

[pubjoe]

If you're looking to make batches I'm interested in buying a set.

 

[BigP_BigP]

If you're looking to make batches I'm interested in buying a set.

I was not planning on it and that was not the intention of this post. There are a few reasons for this, but things could change if there was enough interest.

Having said that because you have to order PCBs in lots of 5 I have 2 (and a half) sets (5 64mb simms and 10 128mb) on hand. If your interested in 1 remaining full set i could work something out with you (i was planning on putting the extra set up on my eBay store at some point anyway).

 

[yoganuggy]

There was a thread on arcade projects about this. The commercial simms are made by darksoft and he feels the open simms are a clone of his work so you can't talk about them there.

Example of closed thread

https://www.arcade-projects.com/threads/interest-check-capcom-cps3-nor-open-simms-batch.32569/

 

[BigP_BigP]

T

There was a thread on arcade projects about this. The commercial simms are made by darksoft and he feels the open simms are a clone of his work so you can't talk about them there.

Example of closed thread

https://www.arcade-projects.com/threads/interest-check-capcom-cps3-nor-open-simms-batch.32569/

Yeah its tricky and i dont really know all the history on that. What i can say from building a set is that they are slightly different but if you made the chang to VLC i suggested above they would start to look very similar indeed. Darksoft is very kind with sharing his work whenever I have asked. I dont really want to annoy him. I personally thought it a little rude to post about a compering product on a forum he uses to distribute his products and had a big part in getting up and running. A bit like sticking an ad for a local hamburger shop up in McDonalds window... probably wouldn't go down well.
I felt this info could help anyone thinking about trying to build some and would be good to have out there but didn't really think it was an option to post it on AP.
Its also why I have been a little reluctant to build a large batch. However with the price of NOR flash I suspect that prices of the commercial option will rise significantly and/or may even become difficult to find. So it would be nice to have both a replacement SIMMs and multigame solution available without totally breaking the bank. After all there are only 6 games and 3 or them are SF3.