ST-V bios 27C400 unable to burn

Vendest

Krauser's Shoe Shiner
Joined
Jun 23, 2016
Posts
240
Hi guys,

I tried to burn a multi-bios for ST-V with mask rom so I've made an ugly on-the-spot adapter 27C400 to 27C4096 but I get some errors upon verifying the rom (after being burnt).

The pin matching seems to be straight forward or am I missing something?
Using a socket to hold the 40 wires onto the Eprom programmer

Thanks

IMG-20170511-WA0007.jpeg
 

kuze

Akari's Big Brother
10 Year Member
Joined
Apr 20, 2013
Posts
2,549
Most likely you have a bad connection somewhere or the EPROM isn't fully erased.

Try erasing the EPROM for longer, or try using a different chip if possible.
 

mainman

CPS2 Person.,
20 Year Member
Joined
Mar 26, 2001
Posts
3,721
Dude you don't need the ghetto adapter. Go to the device menu and select 27c4100
 

Vendest

Krauser's Shoe Shiner
Joined
Jun 23, 2016
Posts
240
Most likely you have a bad connection somewhere or the EPROM isn't fully erased.

Try erasing the EPROM for longer, or try using a different chip if possible.

I rebuilt the adapter and made sure the connections were all good. I Eeased and tried 4 Eproms AM27C400

Dude you don't need the ghetto adapter. Go to the device menu and select 27c4100

I am still getting errors when I select 27C4100 and insert the Eprom w/o adapter.
It reads, blanks and burns but doesn't show correct data after verifying.
I tried using different settings w/ adapter 27c4002, 27c4096, 27c240...
Using topwin7 on TOP3100. Topwin6 doesn't seem to be compatible with the programmer.

"The ghetto adapter" :lol: you nailed it

IMAG0180.jpg
 

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,748
If it's an MX EPROM I think it needs 12v for program. On my Top2049, it does the same.
 

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,748
I rebuilt the adapter and made sure the connections were all good. I Eeased and tried 4 Eproms AM27C400



I am still getting errors when I select 27C4100 and insert the Eprom w/o adapter.
It reads, blanks and burns but doesn't show correct data after verifying.
I tried using different settings w/ adapter 27c4002, 27c4096, 27c240...
Using topwin7 on TOP3100. Topwin6 doesn't seem to be compatible with the programmer.

"The ghetto adapter" :lol: you nailed it

View attachment 44687

Oh and for 4100 I usually just buy them from buyicnow and have him program it for me. Saves me the headache.
 

kuze

Akari's Big Brother
10 Year Member
Joined
Apr 20, 2013
Posts
2,549
I haven't had the best of luck with AMD (AM) chips and the Top3000 in general, usually MX chips are the best bet if they have the type of EPROM you're looking for.
 

skate323k137

Professional College Dropout
10 Year Member
Joined
Jan 7, 2013
Posts
4,186
27c400 are always a pain, I've seen a high failure rate with them. I just double the image to a m27c800 and ground the highest address line.
 

mainman

CPS2 Person.,
20 Year Member
Joined
Mar 26, 2001
Posts
3,721
I never had problems burning 27c400 with either my top2049 or smartpro 5000U
 

skate323k137

Professional College Dropout
10 Year Member
Joined
Jan 7, 2013
Posts
4,186
My top3000 will burn them, but the blanks I've gotten are always shitty and have a high failure rate. Sometimes re-erasing them will do it but even then it's hit or miss.
 
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