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twistedsymphony

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@twistedsymphony - thanks for all the knowledge on these MVS conversions you provided! I have been using your info on a few threads here and I'm sure you saved me countless hours of desoldering and messing with jumpers.
Thanks for the kind words. I'm glad you've found it useful.

I've debated writing an all-encompassing guide but there's SOOO MUCH information and there are literally dozens of ways to accomplish the same conversion. some paths are objectively better than others depending on the game and what you have for donors but there's nothing that's a "this is the one right way to do it". so then it becomes do I explain all of the options, or do I display only some of them etc.
 

LittleLarrySellers

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do I explain all of the options, or do I display only some of them etc.
Yeah, I can see how daunting of a task an exhaustive explanation would be. You definitely hit on the key points to get me going. Seems like once you have an understanding of the mechanics of the 2 boards you kind of have to use some instincts and lean on experience after that.
 

s8n

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hi twisted , i just wanted to let you know i'm still waiting for the EPROMs from buyicnow. It's been 61 days , last batch took 92 days. So i'm still here and alive , i haven't done a hit and run without a thank you.

keep rockin

s8n
 

rcboosted

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Thanks for the kind words. I'm glad you've found it useful.

I've debated writing an all-encompassing guide but there's SOOO MUCH information and there are literally dozens of ways to accomplish the same conversion. some paths are objectively better than others depending on the game and what you have for donors but there's nothing that's a "this is the one right way to do it". so then it becomes do I explain all of the options, or do I display only some of them etc.

twistedsymphony, thank you for these conversion pro tips, they are invaluable. This thread has more info than all the threads/videos I've read/watched on conversion so far, by far. I've been trying to find info on how to burn a diagnostic cart (z80) and monitor test tool. (TL886 still in the mail) But being a newbie and having to piece information here and there proved slow going. From the many threads and videos of small info here and there, I haven't figured out how yet. Then this seemingly unrelated thread might just have my information.

It would be great if there's a conversion guide. It does sound like a lot, but perhaps it can start with this conversion. With some expanded explanation on maybe the jumpers or why certain boards etc. Then other people can use the explanation to expand beyond just this game. Or just start with a list of cheap common games with boards that can easily be used for conversion. I wouldn't mind summarizing what was done for quicker/easier reference. Maybe I'll start looking a list of games that use the boards you referenced and cross that with pricing info so we can find the cheapest donor cart for conversion. If you can provide some info, I can do some leg work in compiling things etc to help things along, if that helps that is.

Once I figured out how to do my diagnostic cart and monitor test tool cart, I will post up my information so others can use it as reference too.

hi twisted , i just wanted to let you know i'm still waiting for the EPROMs from buyicnow. It's been 61 days , last batch took 92 days. So i'm still here and alive , i haven't done a hit and run without a thank you.

keep rockin

s8n
That's a bummer about buyicnow, 92 days for delivery? holy cow. I was about to pick some up for my conversion, but maybe I need a different source.
 

s8n

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hi rc , at the time flights were cancelled (due to cough cough) and it was xmas time. I believe US folks will get there EPROMs sooner , hope that helps
 

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I went through the post and summarized everything for readability, maybe the guide can start with this. If anything, it helped me get clarity on what needs to be done. I hope twistedsymphony and s8n doesn't mind. Please feel free to let me know if there are any corrections or clarifications needed. Working on the game list next. I hope posting cart list for possible conversion won't piss people off.

Every ROM for Pochi Nyaa is encrypted, we need Decrypted P-ROMs, V-ROMs, C-ROMs, M-ROM and the extracted S-ROM (derived from the encrypted C-ROMs)

For conversions PROG-BK1 is the most versatile donor PROG board (will work for any conversion that's possible)
CHA boards CHA256, CHA256B, or CHA512Y will support any possible conversions.
Since this is such a small game you could also Use PROG-TOP, PROG-GSC, PROG-GSC3, or PROG 4096 as well as CHA 42G-3, or CHA 42G-3B
Any other donor boards are not recommended as the PCBs used plated through-holes which makes de-soldering difficult.

impossible conversions are one that use C-ROMs and V-ROMs larger than what can be burned to 27c322 (32Mbit) and 27c160 (16Mbit)EPROMs).

OP went with World Heoroes 2 Cart, PROG 4096 B and CHA 42G-3

For the PROG Board, use 27c800:
Set you jumpers on PROG 4096B similar to Super Side Kicks 2:
https://www.mvs-scans.com/index.php/File:Super_sidekicks_2_set4_b1_front.jpg

Split decrypted V1 ROM into two files and burn to 2x 27c160 for V1 (lower half) and V2 (upper half)

For the CHA Board CHA 42G-3:
No jumper changes needed

The S-ROM is always burned to a 27c301 (aka 27c1000 "non JEDEC", buy any brand other than Marconix)

The M-ROM is oversized, you'll need to burn to a 27c040 (aka 27c4001)
Wire mod needed on M-ROM EPROM
Lift pin 31 (A18 ) before soldering it to the PCB so that it doesn't make contact with the 5V connection
run a wire from pin 31 (A18 ) to A18 on the NEO-ZMC chip (Pin 9).
This needs to be done any donor PCB. Based on WH2 scan, this is required

https://www.mvs-scans.com/index.php/World_Heroes_2

C-ROMs
As this CHA board only supports up to 27c160 sized EPROMs (16Mbit), and the size of the Pnyaa C-ROMs is 64Mbit
It needs to be split twice requiring 8x 27c160s
C1 will be split into 4ths and become C1 C3 C5 and C7
C2 will be split into 4ths and become C2 C4 C6 and C8

Op went wit the following chips
P-ROM x1 ST M27C800-100F1
V-ROM x2 ST M27C160-100F1
C-ROM x8 ST M27C160-100F1
S-ROM x1 ST M27C1000-12F1
M-ROM x1 ST M27C4001-10F1
 
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twistedsymphony

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That's a good summary for this particular conversion on Op's particular Donor cart.

The problem with a generic MVS conversion guide is you've got 200+ games each with up to a dozen different ways you could accomplish the conversion.

the closest thing to a guide is the info I've posted here: https://www.arcade-projects.com/threads/options-for-conversion-of-this-mvs-boot.6544/

I've decoded the jumper configs on a few other PCBs since then. It's difficult write a guide that is both generic and doesn't require a deep understanding of how ROMs work... you can get one or the other but not both.
 
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rcboosted

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@twistedsymphony You are a wealth of information. The thread you linked is indeed a guide, at least to me. The .de site has so many conversions samples that I think it should cover a lot of cases. So much more for me to learn, thank you for sharing your knowledge. I've got some carts coming and hopefully I can at least replicate some of these conversion for my own use. Personally I think example guides will be enough, a comprehensive generic guide like you said, it just too board to cover all cases. But as someone does more conversions, they should understand the other different ways to do them as well.
 
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