Mod8-9B
The Mod8-9 was a combo board that had both RAM and ROM on it. The original board had a 2k 8316 ROM that contained a copy of Monitor 8 along with Robert Swartz's MIL cassette routine (located at 007000-007377), 1k of 1702A EPROM and 1k of MIL MF2113-2P RAM. Since the MIL RAM is nearly impossible to get a hold of, as is a pre-programmed 8316 with Monitor 8, I decided to use the more common 2716 EPROM and Intel 22-pin 2101 RAM instead. Unfortunately neither are a 100% pin compatible with the original chips, so the board had to be modified. No documentation was found for the MIL MF2113-2P RAM, so the pin-outs had to be reverse engineered from the original Mod8-9 board layout. Only two pins that could not be determined with certainty, these were CE2 and OD, however this did not matter for this application. The modified board was given the designation Mod8-9B to distinguish it from the original.
Mod8-6C
Robert Swartz's MIL cassette interface requires that the card be inserted in one of the two I/O slots in the Mod8-8 board. This would mean that you could not have one of the Mod8-6 or Mod8-7 boards in the system if you wanted to use the cassette to load or save data. Fortunately there is plenty of room on the Mod8-6 board for additional circuitry. It was not too difficult to add the cassette interface to that card. The result was what I call the Mod8-6C (C for Cassette).
Over the next few weekends I hope to test these out and make sure they work before I order a production run for sale.