Monday, August 30, 2021

BPROM Adapter (14 in 1)

This blog is dedicated to my hobby "documenting, dumping, decapping, preserving games and all kind of software and constributing all this to MAME and other community's. Emulation got my attention in 1998 and while i used MAME since 2001 for playing the good old Arcade-Games, it took 7 years more until i started to constribute to MAME. 

Starting with an cheap WILLEM programmer, i only could dump the standard eprom's at the beginning. Even until 2011 and while i already had dumped many undumped and new games, i always had to ship the BPROM's via post-mail to f205v in Italy for dumping it. All changed, when i bought myself an expensive GALEP5 programmer and asked CONITEC (the company which produces this little monster) if they can add support (reading and writing) for BPROM's. => which they did! (for free!)

So for reading BPROM's these days, you have most likely only two choices:

1. Buy an modern extremely expensive programmer! (400EUR+)

2. Buy an very old programmer, which is in most cases also expensive today and even hard to get running these days on modern computer-systems.


So dumping Bi-polar PROM's (BPROM's) is in most cases nothing you can do with your average programmer. And that's also, why many external constributions to MAME are missing the dumps of the BPROM's.

My goal of this project is to make simple tools/adapters so anybody can dump even extremely rare chips with an cheap programmer.


While you can find single BPROM-Adapters on the web, there was no All-In-One-Solution so far.

I designed this 14-in-1 Adapter-Package to fit in the 10x10cm PCB-Production. It's cheap and easy for selfsoldering.

The adapter support's READING the following BPROM's and even the 2708 EPROM:

  • 82S123 (32 byte)
  • 82S129 (256 byte)
  • 82S131 (512 byte)
  • 82S135 (256 byte)
  • 82S137 (1 kbyte)
  • 82S141 (512 byte)
  • 82S147 (512 byte)
  • 82S181 (1 kbyte)
  • 82S185 (2 kbyte)
  • 82S191 (2 kbyte)
  • 82S195 (4 kbyte)
  • 82S321 (4 kbyte)
  • 82S641 (8 kbyte)
  •  2708 (1 kbyte)

Of course it also supports the equivalent BPROM's from other company's like the 24S10 or 74S287 for the 82S129.

 All BPROM's can get read as 2716 or 2732 (see the markings on the adapters) which should be supported by any programmer.

For reading 2708 eproms, you will need an external power-supply, which get's the needed +12V and -5V...just connect it to the adapter and read it as 2716.


Reading the BPROM's as 2716 will give you a 2kb file. Split the file to the correct sizes of the BPROM (The size of the BPROM is written above at the list of supported BPROM's) and you will get your correct dump of the bprom! (example 82s123: Split the 2kb file in pieces of 32byte each. All pieces should have the same CRC. Enjoy your BPROM-dump!)

If your programmer supports a "PIN-Check" before dumping you can have "1 Missing Pin" on some of the BPROM's. That's OK, don't worry ;-) !


Needed parts:

  • 7 pcs 40 Pin 1x40 Male 2.54 Breakable Pin Header

  • 3 pcs 1P2T Toggle Switch

  • 2 pcs DIP16 IC Socket
  • 1 pcs DIP18 IC Socket
  • 3 pcs DIP20 IC Socket
  • 2 pcs DIP24 IC Socket
  • 1 pcs DIP24 IC Socket (wide)

  • PCB Files: You can order the boards here.


All together this will cost you about 10EUR.


  1. Despite what you say here there is NO gerber download link on pcbway.....

    1. Correct...i removed the download because of different reasons.
      Currently yoi can only order the pcb's with the link

  2. Just want to leave a comment to help others. I ordered a set of PCBs from the PCBway link and soldered up the 82S123 slot. Reading as a 2716 indeed worked, although the latter part of the buffer got corrupted for me. This blog post says that a 82S123 should read as 256 bytes, but I (re)checked the data sheet and am pretty sure that this part is only 32 bytes big. So when splitting the buffer, use only the first 32 bytes and throw the rest away. Hope that helps!

    1. Thank you! You are correct! Looks like i mixed up 32byte and 256bit. Of course, the 82s123 is just 32byte!
      I corrected the blogpost!