Fix your Digibridge or back up your EPROMs so you can keep it running forever! EPROMs and PALs have often been known to fail after a few decades. Feel free to share this info or to post it on your own web site. HOME
1659 1692 1689 Digibridge - Newer models with the sloped display bezel and square power button.
Below is the internal logic diagram for IC U28 on the Digibridge Motherboard. This is a common PAL16L8 PLD chip available from numerous manufacturers. Genrad part number of the programmed part was 1689-2803 00/A as can be seen from the sticker on the chip. The chip is simply used for address decoding so the security fuse is not actually being used. Therefore the device can be read on a programmer and you can make yourself a backup of the jedec file to CDROM.
ICs U11 and U40 on the Digibridge Motherboard are 256x8 PROMs which are used for sinewave generation. Genrad part number of the programmed part was 5627-0002 00/A as can be seen from the sticker on the chip, and the checksum is 8000. The device can be read on a programmer as Texas Instruments TPB28L22, National Semiconductor 74S471, Monolithic Memories Inc 6309, or Signetics 82S135, which are all equivalent.
The EPROM on the Digibridge Motherboard is a 27256 and you will have a different one depending on the exact model of Digibridge you have.
1659 Digibridge: Part number is 1659-2800 00/B and checksum is 52ED1D
1692 Digibridge: I don't know, PLEASE email me your info if you can
1689 Digibridge: I don't know, PLEASE email me your info if you can
1659 1689 Digibridge - Older models with the vertical display bezel and round power button.
The two 256x8 PROMs are used for sinewave generation. Genrad part number of the programmed part was 5627-0002 00/A as can be seen from the sticker on the chip, and the checksum is 8000. The device can be read on a programmer as Texas Instruments TPB28L22, National Semiconductor 74S471, Monolithic Memories Inc 6309, or Signetics 82S135, which are all equivalent.
The EPROMs on the Digibridge Motherboard are 2764s and you will have different ones depending on the exact model of Digibridge you have.
1659 Digibridge: I don't know, PLEASE email me your info if you can
1689 Digibridge: I don't know, PLEASE email me your info if you can
I do not gaurantee the accuracy or safety of any information herein.
|
HOME |
|