Eprom problem *fixed now*

[Dreamgast]

Hello all,
I bought next things.

Eprom UV eraser
Eprom programmer TOP853
5 eproms : M27C256B

Now , i am trying to write Sonic Edusoft , triple trouble , Sonicboy , etc.
I can not succeed this.
Is this Eprom programmer a good device or do i just have the wrong eproms.
The programmer says , succes completed.
When i try the soldered cart , the screen stays black on my SMS.

I think this programming is too high for me.
Or am i doing something wrong?

OR ... Can maybe anyone write 5 eproms for me please?

I spended lots of money on this things becose i wanted to do it myself to make me proud.
Feeling a bit down becose of the fail

Thank you.

[playgeneration]

Seems you are confusing kilobits with kilobytes. A M27C256 is only 32kb of ROM space, which isn't big enough for those games. Try programming a 32kb game like Ghost House or Hang On and see if that works.

[Dreamgast]

Ok , i wil shure do that.
So i have the wrong eproms bought maybe?
I ordered a socket , when i have that i wil be able to test better.
Should i best erase them before use with UV eraser?
They are new. But maybe it need something like a "format"

Thx for the reply.

[Dreamgast]

Ohw my ... IT WORKS!
Thank you playgeneration!
Now , what is the right eprom i need to write a game?
Lets say a very big one. So i have space enougfh.

Thank you.

[Ichigo]

128ko game => 27c010 or 27c1001 (1 Megabit)
256ko game => 27c020 or 27c2001 (2 Megabits)
512ko game => 27c040 or 27c4001 (4 Megabits)

game bigger than 32k need a mapper inside the cart to function properly. If you don't want to modify a cart to make a repro, take a game with the same size, no modification will be necessary.

See here :
www.smspower.org/Development/SMSPagingChips

Good luck ^^

[Dreamgast]

Ok thank you for the information.
Seems i still need to learn a lot.
But thats the fun part of it
Im gonna try a bigger game after i have bought some eproms.
Its not realy to make games for my collection (in a way)
I have the complete EU PAL collection exept for 4 tittles.
And i wil complete it with originals.
Now buying US games piece by piece.
But i have many reprogrammed SMS roms and the unreleased "Sonic Edusoft".
Im gonna make that litle collection of my own home burned games.

Another question ...

I have about 15 doubles.
But most are with 2 chips on it.
Can i use these game motherboards too to put a own burned eprom on it?
Or is this not gonna work?

Thx

[Ichigo]

depends on what you tell "2 chips"

To make a mod (more than 32ko) you need a mapper on the cart:
easy to recognize, only 3 exists :

315-5208 - 128ko game - found in global defense, Ghostbusters

315-5235 - 128 to 512ko games - found in after burner(512ko), monopoly(128ko + save)...

315-5365 - 256ko game - found in operation wolf, taito chse HQ...

for example : Sonic edusoft is 256ko, so use an Operation Wolf (untill today, I always find a mapper in !), a 27c020 eprom, no redirection, just desolder the old rom (not the one with 315-5365, be carefull ),solder you burned game and enjoy ^^

[Dreamgast]

Ok thx ,
I have a operation wolf and shase hq in my doubles.
Il use that one for edusoft then.
Easyest for me sinds i have the game double
Intresting information , thank you for helping out.

[Dreamgast]

Got my eproms in today and started on it straight away ;D

The sonic edusoft plays on my SMS now.
I had to download it again becose the first time it didnt work.
This becose my ROM file was not working.
Then i found a working one names "EDUSOFT_HAX2" on the net.
With this one it succeeded on a Operation Wolf cart and another eprom.

[Dreamgast]

I have downloaded a 800kb rom for master system.
I would like experiment with this.
Is this the 27c060 or 27c080 eprom i need?
Or another type rom?
And what game motherboard can take this rom please?
Thx

[playgeneration]

512kb is your limit, unless you fancy building a custom made mapper chip yourself.

[gallos_11]

I think some TecToy games like Street Fighter 2 are 800kb...

[playgeneration]

Sept 5, 2010 10:21:12 GMT gallos_11 said:

I think some TecToy games like Street Fighter 2 are 800kb...

Yes but those games rom have an internal mapper.

[gallos_11]

Sept 5, 2010 10:26:16 GMT playgeneration said:

Yes but the game rom has an internal mapper.

Oh thanks for the info, I'm novice in eprom development...

[Dreamgast]

Thx for the info.
Yes its the street fighter 2 indeed that i downloaded.
Making a custom mapper wont be for me im afraid.
The sonic blast BR. is even 1024kb.
I wonder how big a SMS can take.