This page documents the steps taken to “upgrade” the ROMs in a standard BDV11.
This BDV11 had only two ROMs in it. They were marked U49 and U54. They were in the locations that I later replaced with 453-1 and 454-1 respectively.
The original ROMs used to conduct a Memory Test and then give a “Start?” prompt. I did limited testing of these original ROMs, but can confirm the entering DD0 or DL1 at this prompt booted TU58 Unit 0 or RL02 Unit 1 respectively.
The original 8-way dipswitch setting was (1-8): 11010010
The original 5-way dipswitch setting was (1-5): 00000 on the first board, and 00001 on the second board
I fitted ROMs 453-1 to 453-4 and 454-1 to 454-4.
The new dipsw setting were:
8-way (1-8): 00000011
5-way (1-5): 00000
The conversation worked great. It greeted me with the following:
KDF11B-BJ ROM V1.1
Apart from the change in dipswitch settings, no changes were required to the BDV11 board.
Note: the board I used had some form of conversion done to it (see photo). Pins BC1-BF1 were connected to an IC (or resistor pack?) via 4 wire jumpers. There were no other obvious modifications to the PCB.
Resources
If you are looking for documentation about the BDV11, a good start is “LSI-11 Systems Service Manual, Volume II” at page 425. This reference has a lot of helpful information about the BDV11, but it doesn’t identify the designator for each ROM socket. The DEC Part Number for this manuals is EK-LSIFS-SV-005. As at 03-SEP-2018, there is a copy of this manual online. I have extracted the BDV11 pages from this manual and they can be downloaded here.