diff --git a/src/desk_acc/res/this.apple.res.bg b/src/desk_acc/res/this.apple.res.bg
index 56159c5c..5c1222f0 100644
--- a/src/desk_acc/res/this.apple.res.bg
+++ b/src/desk_acc/res/this.apple.res.bg
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "u-wo za zapis na danni"
 .define res_string_card_type_network "mrevowa karta"
 .define res_string_card_type_mockingboard "MOCKINGBOARD"
+.define res_string_card_type_phasor "PHASOR"
 .define res_string_card_type_z80 "Z-80 SOFTCARD"
 .define res_string_card_type_uthernet2 "UTHERNET II"
 .define res_string_card_type_passport "PASSPORT MIDI"
diff --git a/src/desk_acc/res/this.apple.res.da b/src/desk_acc/res/this.apple.res.da
index 2c04b6da..daeb7fb6 100644
--- a/src/desk_acc/res/this.apple.res.da
+++ b/src/desk_acc/res/this.apple.res.da
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "Masselagring"
 .define res_string_card_type_network "Netv{rkskort"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Z-80 SoftCard"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/res/this.apple.res.de b/src/desk_acc/res/this.apple.res.de
index dbcf67c7..a6b7f867 100644
--- a/src/desk_acc/res/this.apple.res.de
+++ b/src/desk_acc/res/this.apple.res.de
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "Massenspeicher"
 .define res_string_card_type_network "Netzwerkkarte"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Z-80 SoftCard"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/res/this.apple.res.en b/src/desk_acc/res/this.apple.res.en
index 13fd40a9..b740404c 100644
--- a/src/desk_acc/res/this.apple.res.en
+++ b/src/desk_acc/res/this.apple.res.en
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "Mass Storage"
 .define res_string_card_type_network "Network Card"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Z-80 SoftCard"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/res/this.apple.res.es b/src/desk_acc/res/this.apple.res.es
index ea6fd67c..912d7130 100644
--- a/src/desk_acc/res/this.apple.res.es
+++ b/src/desk_acc/res/this.apple.res.es
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "Dispositivo de Almacenamiento"
 .define res_string_card_type_network "Tarjeta de Red"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Tarjeta Z-80"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/res/this.apple.res.fr b/src/desk_acc/res/this.apple.res.fr
index 245b95bb..04bc721b 100644
--- a/src/desk_acc/res/this.apple.res.fr
+++ b/src/desk_acc/res/this.apple.res.fr
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "M{moire de masse"
 .define res_string_card_type_network "Carte r{seau"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Carte Z-80"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/res/this.apple.res.it b/src/desk_acc/res/this.apple.res.it
index 207656df..bc9a3747 100644
--- a/src/desk_acc/res/this.apple.res.it
+++ b/src/desk_acc/res/this.apple.res.it
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "Memoria di massa"
 .define res_string_card_type_network "Scheda di rete"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Scheda Z-80"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/res/this.apple.res.nl b/src/desk_acc/res/this.apple.res.nl
index 84fcba87..0c1b0f82 100644
--- a/src/desk_acc/res/this.apple.res.nl
+++ b/src/desk_acc/res/this.apple.res.nl
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "Massa-opslag"
 .define res_string_card_type_network "Netwerk kaart"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Z-80 SoftCard"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/res/this.apple.res.pt b/src/desk_acc/res/this.apple.res.pt
index 8d2782f0..176a0eba 100644
--- a/src/desk_acc/res/this.apple.res.pt
+++ b/src/desk_acc/res/this.apple.res.pt
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "Dispositivo de armazenamento"
 .define res_string_card_type_network "Placa de Rede"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Placa Z-80"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/res/this.apple.res.sv b/src/desk_acc/res/this.apple.res.sv
index 2d31cb42..b4fd7722 100644
--- a/src/desk_acc/res/this.apple.res.sv
+++ b/src/desk_acc/res/this.apple.res.sv
@@ -53,6 +53,7 @@
 .define res_string_card_type_storage "Masslagring"
 .define res_string_card_type_network "N{tverkskort"
 .define res_string_card_type_mockingboard "Mockingboard"
+.define res_string_card_type_phasor "Phasor"
 .define res_string_card_type_z80 "Z-80 Kort"
 .define res_string_card_type_uthernet2 "Uthernet II"
 .define res_string_card_type_passport "Passport MIDI"
diff --git a/src/desk_acc/this.apple.s b/src/desk_acc/this.apple.s
index 037cdf99..840ca3b8 100644
--- a/src/desk_acc/this.apple.s
+++ b/src/desk_acc/this.apple.s
@@ -743,6 +743,7 @@ str_audio:      PASCAL_STRING res_string_card_type_audio
 str_storage:    PASCAL_STRING res_string_card_type_storage
 str_network:    PASCAL_STRING res_string_card_type_network
 str_mockingboard: PASCAL_STRING res_string_card_type_mockingboard
+str_phasor:     PASCAL_STRING res_string_card_type_phasor
 str_z80:        PASCAL_STRING res_string_card_type_z80
 str_uthernet2:  PASCAL_STRING res_string_card_type_uthernet2
 str_passport:   PASCAL_STRING res_string_card_type_passport
@@ -1700,7 +1701,12 @@ sigtable_xdrive:        .byte   4, $07, $3C, $0B, $B0, $0C, $01, $F0, $CA
 
         CALL    WithInterruptsDisabled, AX=#DetectMockingboard
     IF CS
-        RETURN  AX=#str_mockingboard
+        CALL    WithInterruptsDisabled, AX=#DetectPhasor
+      IF CS
+        RETURN  AX=#str_phasor
+      END_IF
+      
+        RETURN  C=1, AX=#str_mockingboard
     END_IF
 
         CALL    WithInterruptsDisabled, AX=#DetectZ80
@@ -1927,6 +1933,7 @@ write:  sta     $C080,x         ; self-modified to $C0n0
 .endproc ; DetectPassportMIDI
 
         .include "../lib/detect_mockingboard.s"
+        .include "../lib/detect_phasor.s"
         .include "../lib/detect_thecricket.s"
 
 ;;; ============================================================
diff --git a/src/lib/detect_phasor.s b/src/lib/detect_phasor.s
new file mode 100644
index 00000000..c45fdca7
--- /dev/null
+++ b/src/lib/detect_phasor.s
@@ -0,0 +1,82 @@
+;;; ============================================================
+;;; Detect Phasor
+;;;
+;;; A Phasor will also be detected as a Mockingboard, so first
+;;; detect the Mockingboard, and if successful detect the Phasor
+;;;
+;;; Inputs: $06 points at $Cs00
+;;; Outputs: C=1 if detected, C=0 otherwise
+;;; Assert: Interrupts disabled
+;;; ============================================================
+
+.proc DetectPhasor
+        ptr := $06
+
+        txa
+        pha                     ; preserve caller's X
+
+        lda     ptr+1           ; $Cs00 high byte
+        and     #$07            ; slot
+        asl
+        asl
+        asl
+        asl                     ; X offset = slot * 16
+        tax
+
+        ;; Force Phasor native mode: $C0(8+s)D
+        lda     $C08D,X
+
+        ;; In native mode, $Cs04 should no longer be VIA0.
+        ldy     #$04
+        jsr     ProbeViaTimerPreserveX
+        bcs     fail_restore
+
+        ;; In native mode, VIA0 timer-low appears at $Cs14.
+        ldy     #$14
+        jsr     ProbeViaTimerPreserveX
+        bcc     fail_restore
+
+        ;; Restore Mockingboard-compatible mode: $C0(8+s)8
+        lda     $C088,X
+
+        pla
+        tax
+        RETURN  C=1
+
+fail_restore:
+        lda     $C088,X
+
+        pla
+        tax
+        RETURN  C=0
+.endproc
+
+.proc ProbeViaTimerPreserveX
+        ptr := $06
+        tmp := $08
+
+        txa
+        pha
+
+        ldx     #2
+
+loop:   lda     (ptr),Y
+        sta     tmp
+        lda     (ptr),Y
+
+        sec
+        sbc     tmp
+        cmp     #($100 - 8)
+        bne     fail
+
+        dex
+        bne     loop
+
+        pla
+        tax
+        RETURN  C=1
+
+fail:   pla
+        tax
+        RETURN  C=0
+.endproc