H89 CP/M hard-secored boot diskette

Wayne, oh yeah, that I know. But there seem to be several revisions at work. I have two (currently dead) '89s that both have part number 444-62 at U518, which I understand from another enthusiast is MTR-89, and will not support the H-37 controller (or at least, it will not boot from it). My working machine, however, has 444-142, which is apparently MTR-90 and OK for that controller. I've also been warned by this person that I can burn my own copies of 444-142 for those other machines, but I have to watch the voltage settings (jumpers) for the EPROM socket *very* carefully. Thanks for the jumper positions, that's a huge help. I'll contact you off-list regarding the docs. A further question if you know: the H-17 seems to require the right-most "slot" on the CPU board (different signals from the other two). The serial card is in the middle slot, so I assume the H-37 can go into the left slot? Also, my H-37 card has a ribbon cable coming off at "P5" on the board and terminating in a DIP header, which I assume connects to the CPU board, but where, and does something else get pulled to make room for it (like the 64K memory expansion hack)? I have HDOS 2.0, but I'll have to scrounge to see if I have that update. Thanks (very much) to Don Maslin, I have a CP/M, will need to check the version. Thanks for the assist! Patrick