The Computereyes double hires capture program is really baffling to me because it never seems to touch the ioudis softswitches at C07E and C07F to turn ioudis off and on.

According to Jon Relay's page, C07E and C07F are the important switches.

Code
C07E 49278 IOUDISON      EC  W    Disable IOU
           RDIOUDIS      EC   R7  Status of IOU Disabling
C07F 49279 IOUDISOFF     EC  W    Enable IOU
           RDDHIRES      EC   R7  Status of Double HiRes

and ioudis is supposed to control access to the annunciators:

Code
C058 49240 CLRAN0       OE G WR   If IOUDIS off: Annunciator 0 Off
           DISXY          C  WR   If IOUDIS on: Mask X0/Y0 Move Interrupts
C059 49241 SETAN0       OE G WR   If IOUDIS off: Annunciator 0 On
           ENBXY          C  WR   If IOUDIS on: Allow X0/Y0 Move Interrupts
C05A 49242 CLRAN1       OE G WR   If IOUDIS off: Annunciator 1 Off
           DISVBL         C  WR   If IOUDIS on: Disable VBL Interrupts
C05B 49243 SETAN1       OE G WR   If IOUDIS off: Annunciator 1 On
           ENVBL          C  WR   If IOUDIS on: Enable VBL Interrupts
C05C 49244 CLRAN2       OE G WR   If IOUDIS off: Annunciator 2 Off
           X0EDGE         C  WR   If IOUDIS on: Interrupt on X0 Rising
C05D 49245 SETAN2       OE G WR   If IOUDIS off: Annunciator 2 On
           X0EDGE         C  WR   If IOUDIS on: Interrupt on X0 Falling
C05E 49246 CLRAN3       OE G WR   If IOUDIS off: Annunciator 3 Off
           Y0EDGE         C  WR   If IOUDIS on: Interrupt on Y0 Rising
           DHIRESON      ECG WR   In 80-Column Mode: Double Width Graphics
C05F 49247 SETAN3       OE G WR   If IOUDIS off: Annunciator 3 On
           Y0EDGE         C  WR   If IOUDIS on: Interrupt on Y0 Falling
           DHIRESOFF     ECG WR   In 80-Column Mode: Single Width Graphics

and according to the Apple IIe Technical reference manual, appendix F: frequently used tables,

Code
IOUDIS W $C07E On: disable IOU access for addresses $C058 to $C05F; enable access to DHIRES switch
IOUDIS W $C07F Off: enable IOU access for addresses $C058 to $C05F; disable access to DHIRES switch

and lower down on the page it says:

Code
 The firmware normally leaves IOUDIS on.

The thing is, I can't find anywhere that touches these softswitches:

Running the apple2e driver with digitalvision_computereyes_dhgr_v2.4.dsk (v2.4 which was found inside of digitalvision_computereyes.zip)
and another version in AIIComputerEyesDHR.DSK (v.1.0 of the capture program)

and setting a watchpoint in the debugger before the driver boots:

Code
wpset c07e,2,rw

and it never hits the watchpoint at all in the capture program.

So it must be still able to modify the Annunciators even with IOUDIS on?

Code
812A: AD 5E C0 lda DHIRESON
812D: 66 01    ror $01
812F: 90 03    bcc $8134
8131: AD 5F C0 lda DHIRESOFF
8134: AD 5A C0 lda CLRAN1
8137: 66 01    ror $01
8139: 90 03    bcc $813e
813B: AD 5B C0 lda SETAN1
813E: AD 5C C0 lda CLRAN2
8141: 66 01    ror $01
8143: 90 03    bcc $8148
8145: AD 5D C0 lda SETAN2
8148: AD 59 C0 lda SETAN0