* SOLVED * Sega MD / Willem 5.0E / 27c322 burn fail

[venomneedle]

So here's the story:

i've been programming for the Sega MD/GEN last few weeks and thought it would be very nice to see the Demo run on actual hardware.

so i read some forums and most point to the willem programmer, although i read some warnings, but i ordered one of those on ebay anyways.

so i got this programmer + 16bit adapter + 10x 27c322



now i wanted to start easy and read a mask rom from the game cartridge (HOOK)
i desoldered the rom and put it on the willem programmer
i pressed the read button, did a byte swap and save it to a file.
i could clearly read SEGA MEGADRIVE in the header of the file.
i opened up Fusion and load the file, but it only gives me a blank screen and a checksum error, so i tried to fix the checksum, but stil gives me a blank screen.

so went back to the interwebs and read some more about the programmer, it seems there are a lot of problems with this thing! starting to wonder if it was the right thing to buy... but i didn't want to give up easily... so found myself an adapter 10Volts 2.2A, most of the problems were voltage related.

tried reading again but still same problem....

also tried 12v 1A adapter and a 9v 1A adapter.

well to bad, it could have been this mask rom was already damaged right?


so tried burning the rom (HOOK download, fixed the checksum) as i own the cartridge it thought it wouldn't be a problem

i tried one, then a second, then a third... all eproms failed, the software told me:
0x000000 chip 0x10 buffer 0xff, and the last time it told me 0x000000 chip 0x04 buffer 0xff

at this point i'm getting pretty anoyed!

now on de 16bit adapter there are some pins called A19 A21 A20 etc etc
these pins are also on the programmer board....so i made a cable to connect these together.

also checked the voltage @ the zif socket, pin 1 = 12.67Volts and pin 32 = 6.29Volts

today i tried again reading but when finished the file is al scrambled, couldn't even find the SEGA MEGADRIVE in the header....

also tried burning again....still to no avail...

so anybody out here that can point me to the right direction?

image:
http://b.imagehost.org/0945/willemprog.jpg

[Ziggy]

now on de 16bit adapter there are some pins called A19 A21 A20 etc etc
these pins are also on the programmer board....so i made a cable to connect these together.

Right. You absolutely have to have these connections. If you noticed the ZIF socket on the programmer is 32-pin, while the 27C322 is a 42-pin EPROM. The extra pins are extra address lines for the chip, you absolutely need to have this connection when reading or writing.

You sure you got the dip switches set correctly? I didn't see you mention that. Also, are you sure that you're selecting the right kind of chip to burn? Maybe that's also your problem when reading - selecting the wrong chip type.

Don't be too discouraged though. My first programmer was pretty much the same one you got. They're very frustrating to figure out how to use them, mostly because the little documentation on them sucks.

When writing with the 16-bit adapter, you need the extra address lines like I said. Make sure all the dip switches are set correctly (the software will tell you how to set them for each chip you select). There's other jumpers on the programmer, but you usually don't have to touch them. The only one I ever had to touch was the jumper directly next to the dip switches. Again, the software will tell you how to set these. And also, check the jumper on the adapter board (though in your pic it looks like you have it set right).

Be sure you're putting the adapter into the ZIF socket on the programmer the right way. And likewise, make sure you're inserting the EPROM into the socket on the adapter the right way.

Other than all those common mistakes, only other thing I can think of off the top of my head right now is to make sure your parallel port is in EPP mode. You can switch it to EPP mode in the BIOS.

I've never tried to read a mask ROM from a Genesis game before, so I can't help you there. I've programmed a lot of 16-bit chips using the same programmer you have though.

edit: I just realized the game you said you were trying to read was Hook. I checked and Hook is an 8Mb game, so if you're trying to read that on the 27C322 (32Mb) setting, that will likely create a problem. You should probably be using the 27C800 setting to read that mask ROM. Again, I've never tried to read a mask ROM before.

[venomneedle]

THANX 4 helping me here!

ok triple checked my settings...set the software to read 27c800. you can see the result in the image:

http://d.imagehost.org/0875/readmask.jpg

it strange, it just skips bytes

tried reading the maskrom as it was a 27c160 & 27c322, both give the same result..

also tried the differen power supply's again, it seems that just using USB from the computer gives the best output so far, which i find strange cause PC USB isn't really stable...

before i try burning again, i'd rather get the reading to work properly, i don't have an UV eraser yet...

W8!

tried moving the cable...
see image:
http://b.imagehost.org/0250/CIMG7452.jpg

and now it works:
http://d.imagehost.org/0044/readmask2.jpg
http://b.imagehost.org/0873/readmask3.jpg

so i'm going to try to burn it back to a 27c322 and see if it works....

well it worked

but i did move over the cable so it's now connected as follows:
on 16bit adapter:
A21,A20,A25,A19,A23
on willem programmer board to:
A21,A20,P1,A19,A23

http://b.imagehost.org/0085/romok.jpg

everything looks ok, but when read back and saved the copied rom gives a checksum error....

i know the original rom is 8MBit while i burn it to a 32MBit, so how do i edit the 8MBit rom to work with a 32MBit rom?

i looked at the total rom size of the 32mbit -> 4.194.304 bytes
then i looked at the original rom -> 1.048.576 bytes

so the missing 3.145.728 bytes can i just fill these with FF in a hex editor? (i know i can but will it work?) then use FixChecksum.exe to fix the checksum before burning it to the eeprom.

[Ziggy]

Why would you even bother burning an 8Mb file to a 32Mb chip? It would just be a waste. Just use an 8Mb chip (27C800). Save the 27C322's for a 24 or 32Mb ROM.

[venomneedle]

well i only have 27c322 roms, and really want to test my demo program...

but i did what you suggested, i took a 32Mbit rom and burned it.

now i connected it to my hook cartridge as found on this website:

http://translate.google.nl/translate?hl ... e-%3D.html

image:
http://sega4ever.power-heberg.com/tutod ... rminer.png

but i only get a blank screen.

i guess the pins have to be connected differently but i don't quite get how..
any clues anyone?

i guess it's because the PCB you see in the picture is a 16Mbit PCB, and hook is only 8Mbit. Couldn't find how to rewire...

[Ziggy]

As far as I know, EPROMs are a 1:1 pinout of Genesis mask ROMs. The few that I've made, that's the way it was. No need to rewire. Just do the byte swap before burning the ROM and you're good to go. Perhaps MegaDrive games have a slightly different pinout?

First make sure you're EPROM is facing the right way. If you're looking at the front of the PCB, the notch on the EPROM should be facing the left side. If that's right, I would try soldering the EPROM directly in without rewiring any of the pins.

Are you sure you did a byte swap to the ROM before you programmed it to the EPROM? If the ROM (gamename.bin) loads and plays fine in an emulator than you have to perform a byte swap before programming.

[venomneedle]

As far as I know, EPROMs are a 1:1 pinout of Genesis mask ROMs. The few that I've made, that's the way it was. No need to rewire. Just do the byte swap before burning the ROM and you're good to go. Perhaps MegaDrive games have a slightly different pinout?

First make sure you're EPROM is facing the right way. If you're looking at the front of the PCB, the notch on the EPROM should be facing the left side. If that's right, I would try soldering the EPROM directly in without rewiring any of the pins.

Are you sure you did a byte swap to the ROM before you programmed it to the EPROM? If the ROM (gamename.bin) loads and plays fine in an emulator than you have to perform a byte swap before programming.

I did read back the rom to check it i did a byte swap, and i did that correctly, so that shouldn't be the problem...

found a possible solution in this french forum:
http://www.sega-board.fr/viewtopic.php?t=3240



if i find the time i'll try this tomorrow, if it works, i think i will translate the complete thing so the rest of the world can enjoy it to

[Ziggy]

I've seen that chart elsewhere before, but I'm not sure what it's suppose to mean.

[venomneedle]

tried it, so far no luck.....
destroyed my Sonic JAP PCB
destroyed my Hook PCB

i'm wondering, is there a pcb layout you know of? i think it would be better to make a new compatible PCB so i don't need donor cards.

I've seen that chart elsewhere before, but I'm not sure what it's suppose to mean.

i guess it means,
Hook is an 8Mbit rom (1MB) so i would have to connect A19 & A20:

[venomneedle]

It actually works now!!!

removed the mask rom from davis cup tennis.
put my demo in an eprom
and connected A19 en A20 as described

here's the result so far:
http://www.youtube.com/watch?v=7yZXaL74o-8


btw: how do you mark a thread as SOLVED?