I recently received an Altair 8800 with an Altair disk drive (Pertec FD514 innards). In said machine is a Solid State Music 2/4k EPROM board with 2 proms: DBL and MBL. My understanding is that the DBL prom is the boot loader for paper tape and cassette and the MBL is the boot loader for the disk. Assuming the PROMS (1702s) still hold data, I need to figure out the address of the code. The board has two sets of four dip switches. One is labeled T1 to T4 and the other A12 to A15. A jumper on the board that allows settings between 2k and 4k is set to 4k (1702s vs 1701s?) Does anyone have a manual or a really good memory of how these relate to the address of the on-board PROMS? I?m also interested in finding out how the sockets are addressed. The two proms are in the lower right sockets (the board has 2 rows of 9) and I?d have thought from the markings that the upper left sockets were the first two to be addressed. I?m not yet that familiar with S-100/Altair type systems, but I assume if I know this address I can execute the code to boot the machine (assuming the drive still works and the disks aren?t bad. . . ) Thanks in advance for any help you can provide. Erik