On 23 Jan 2012 4:44am, John Robertson wrote:

David Shoemaker wrote:

According to mame there is rom covering the entire memory range from0-FFFF

ROM Regions:
...

So the ram / rom address space must be bank switched. Question is how to do
that so I can get a good ram test with the fluke? I can do rom tests just
fine so the board must default to the rom bank's.

Suggestions?

As I recall the Defender Technical Service manual covered the bank switching in either the first (early board - 1 24 pin PROM) or second (2 PROM later boards) editions.

Yup, it's there...page 15 (Video Ram Control) of manual 16P-3001-301. Pretty sure they didn't change that at all (or very much?) for later boards.

The Memory map for Robotron etc is completely different to defender which is why the boards are not compatible in the slightest.

From my notes that I use my 9010 with on Williams games, hope this helps!

Robotron Type Game Boards

Video RAM    0000 ->    97FF
Game RAM    9800 ->    BFFF
Colour RAM    C000 ->    C00F
CMOS RAM    CC00 -> CFFF
ROM    0000 ->    8FFF        (in 1000h blocks – 2732’s)
ROM    D000 ->    FFFF        (in 1000h blocks – 2732’s)

ROM/RAM Toggle    C900        (FF=RAM, 00=ROM in 0000 -> 8FFF)

PIA (Widget)    C804 -> C807
PIA (ROM)    C80C -> C80F

Special Chips    CA00 -> CA07
Watchdog        CBFF
Video Counters        CB00        (6 bits of video counter chain)

Robotron type games need ROM 12 to do ROM test/rug (11 for Sinistar).

Defender Game Boards

Video RAM    0000 ->    97FF
Game RAM    9800 ->    BFFF
Colour RAM    C000 ->    C00F
CMOS RAM    C400 -> C4FF

ROM (Banked)    C000 ->    CFFF        (Bank Switched)
ROM (Static)    D000 ->    FFFF        (Not Bank Switched)

ROM Bank Select    D000        (0 = I/O, 1=Bank 1, 2=2, 3=3, 7=4)

PIA (Widget)    C804 -> C807
PIA (ROM)    C80C -> C80F

Watchdog        C3FC
Video Counters        C800        (6 bits of video counter chain)

Defender games need ROM 3 to rug and 3, 7, 8, 10 & 11 to do ROM test.