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So, what chip belongs here?

My board seems to be missing it entirely.

27583604_10156015330252207_114586048_n.jpg
 
I'm going to guess a PROM of some kind, whatever BD01/02/04 are - since the slot is marked BD03
 
I'm going to guess a PROM of some kind, whatever BD01/02/04 are - since the slot is marked BD03
It is.
82S123

If someone has a dump of it I can convert it to a GAL16V8 for you (it's probably the best or least worse replacement available today).
But you're going to need an adapter (completely different pinout):
http://www.jammaplus.co.uk/forum/forum_posts.asp?TID=76000&title=gal-to-82s123-prom-pcbs
Or some wire hackery...

[EDIT]

Seems to be in MAME.

[EDIT 2]
It's 82S129
GAL replacement chip is longer (DIP20 vs DIP16) but should fit easily. As Caius said just connect pin 10 (ground on the GAL) to pin 8 (which is originally the ground pin on the PROM).
 
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Is it confirmed to be a 82S123?I converted the MAME dump to equations and I can see data only on four outputs (while the 82S123 had eight of them) so in my opinion it's a 82S129 which, indeed, has four outputs.Can you check, please, the type of the other BPROMs on your board?
 
I converted the dump (which is from an 82S129 so 256 bytes of data - 256 x 4-bit device- while dump of a 82S123 is 32 bytes - 32 x 8-bit device-) in a GAL.Burn the attached .jed in a GAL16V8 and tie pin 8 and 10 together before install the chip in the socket.Let us know if you manage to fix your board with this.Thanks.
 

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  • bd03.11k_GAL16V8.zip
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Is it confirmed to be a 82S123?I converted the MAME dump to equations and I can see data only on four outputs (while the 82S123 had eight of them) so in my opinion it's a 82S129 which, indeed, has four outputs.Can you check, please, the type of the other BPROMs on your board?
I'd love to check the other proms but they're illegible :(. My board looks to have lead a rough life prior to my owning it.

I ordered an extra gal16v8 for a different project just in case. I think it showed up in the mail yesterday, so I'll give it a shot tonight if so.

Thank you!!
 
Judging from size of MAME dumps all the devices are 82S129 (or compatible ones).Is your board dead without the chip?
 
Thanks for picture.Confirmed, all the BPROMs are Fujitsu MB7114 (256 x 4-bit) compatible with Signetics 82S129 and other.My GAL recreation should work as replacement of the missing one but testing on PCB will give us the definitive answer (unless the board has other issues)
 
Thanks for picture.Confirmed, all the BPROMs are Fujitsu MB7114 (256 x 4-bit) compatible with Signetics 82S129 and other.My GAL recreation should work as replacement of the missing one but testing on PCB will give us the definitive answer (unless the board has other issues)
Well, after testing we will know if it has other issues or not! :)
 
Is it confirmed to be a 82S123?I converted the MAME dump to equations and I can see data only on four outputs (while the 82S123 had eight of them) so in my opinion it's a 82S129 which, indeed, has four outputs.Can you check, please, the type of the other BPROMs on your board?
My bad Caius, I misread the ref (not easy with the BD 0x marking on top of it). I can confirm it's a 82S129.
Good job on the GAL replacement!
 
My bad Caius, I misread the ref (not easy with the BD 0x marking on top of it). I can confirm it's a 82S129.Good job on the GAL replacement!
Thanks but let's wait for the testing on PCB.
 
My bad Caius, I misread the ref (not easy with the BD 0x marking on top of it). I can confirm it's a 82S129.Good job on the GAL replacement!
Thanks but let's wait for the testing on PCB.
It can only but work. It can be seen as a table with 8 inputs and 4 outputs.Only /CE signals can be problematic.
Correct.If the /CE lines are tied to GND then no problem, pins can also be omitted in equations.But if they receive a signal, then we have to declare OE equations for each ouput.So, @rewrite can you check if pin 14 and 15 of the socket of the missing BPROM are tied to GND?
 
Even if only one of the /CE signal is tied to ground or if both pins are tied together it should work if you use the /OE pin of the GAL and the .OE syntax in the equations.
This way you can drive 3 state outputs (but pinout doesn't match for the /OE and /CE signals).
 
Even if only one of the /CE signal is tied to ground or if both pins are tied together it should work if you use the /OE pin of the GAL and the .OE syntax in the equations.
This way you can drive 3 state outputs (but pinout doesn't match for the /OE and /CE signals).
In my experience, if the /CE lines are permanently tied to GND, you can ignore them when you declare I/O in equations, it will work the same.But if they get toggling signals, then you have to declare something like this as inputs :

PIN 17 = CE1
PIN 18 = CE2

and like this (for each output)

D0.oe = !CE1 & !CE2;
 
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My bad Caius, I misread the ref (not easy with the BD 0x marking on top of it). I can confirm it's a 82S129.Good job on the GAL replacement!
Thanks but let's wait for the testing on PCB.
It can only but work. It can be seen as a table with 8 inputs and 4 outputs.Only /CE signals can be problematic.
Correct.If the /CE lines are tied to GND then no problem, pins can also be omitted in equations.But if they receive a signal, then we have to declare OE equations for each ouput.So, @rewrite can you check if pin 14 and 15 of the socket of the missing BPROM are tied to GND?
Forgive me, because I'm still new at this, but I'm really trying to learn. Tied to GND would mean it has continuity with the GND on the JAMMA edge, right? I just don't want to give the wrong answer because I misunderstood the terminology.

If so, then Pin 14 (CE2 according to the pinout of 82S129) is tied to GND, and 15 (A7) is not.
 
In my experience, if the /CE lines are permanently tied to GND, you can ignore them when you declare I/O in equations, it will work the same.But if they get toggling signals, then you have to declare something like this as inputs :
PIN 17 = CE1
PIN 18 = CE2

and like this (for each output)

D0.oe = !CE1 & !CE2;
What I wanted to say is it's still possible to have 3 state outputs if one of the /CE lines isn't tied to ground our if both are connected together to something different to ground.
Even if the GAL only have one /OE input.
Forgive me, because I'm still new at this, but I'm really trying to learn. Tied to GND would mean it has continuity with the GND on the JAMMA edge, right? I just don't want to give the wrong answer because I misunderstood the terminology.
If so, then Pin 14 (CE2 according to the pinout of 82S129) is tied to GND, and 15 (A7) is not.
What about pin 13 (/CE1)?
 
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