diff --git a/imul8xe.s b/imul8xe.s
deleted file mode 100644
index 855e044..0000000
--- a/imul8xe.s
+++ /dev/null
@@ -1,175 +0,0 @@
-FR0    = $d4 ; float48
-PORTB = $d301
-
-
-EXTENDED_RAM = $4000 ; 16KiB bank on the XE
-
-; lookup table for top byte -> PORTB value for bank-switch
-.align 256
-bankswitch:
-    .repeat 256, i
-        .byte ((i & $c0) >> 5) | $c1
-    .endrepeat
-
-; 58-77 cycles
-; clobbers x, y, dest to dest + 3
-.macro imul8xe dest, arg1, arg2
-.local done
-.local output
-.local ptr
-
-    output = dest
-    ptr = dest + 2 ; scratch space assumed
-
-    ; bottom 14 bits except the LSB are the per-bank table index
-    ; add $4000 for the bank pointer
-    lda arg1     ; 3 cyc
-    and #$fe     ; 2 cyc
-    sta ptr      ; 3 cyc
-    lda arg2     ; 3 cyc
-    and #$3f     ; 2 cyc
-    clc          ; 2 cyc
-    adc #$40     ; 2 cyc
-    sta ptr + 1  ; 3 cyc
-    
-    ; top 2 bits are the table bank selector
-    ldx arg2          ; 3 cyc
-    lda bank_switch,x ; 4 cyc
-    sta PORTB         ; 4 cyc
-
-
-    ; copy the entry into output
-    ldy #0       ; 2 cyc
-    lda (ptr),y  ; 5 cyc
-    sta output   ; 3 cyc
-    iny          ; 2 cyc
-    lda (ptr),y  ; 5 cyc
-    sta output+1 ; 3 cyc
-
-    ; note: we are not restoring memory to save 6 cycles!
-    ; this means those 16kb have to be switched back to base RAM
-    ; if we need to use them anywhere else
-    ;;; restore memory
-    ;;lda #$81     ; 2 cyc - disabled
-    ;;sta PORTB    ; 4 cyc - disabled
-
-    ; check that 1 bit we skipped to fit into space
-    lda arg1     ; 3 cyc
-    and #1       ; 2 cyc
-    beq done     ; 2 cyc
-
-    ; add the second param one last time for the skipped bit
-    clc          ; 2 cyc
-    lda arg2     ; 3 cyc
-    adc output   ; 3 cyc
-    sta output   ; 3 cyc
-    lda #0       ; 2 cyc
-    adc output+1 ; 3 cyc
-    sta output+1 ; 3 cyc
-
-done:
-.endmacro
-
-.macro bank_switch bank
-    lda #((bank << 1) | $c1)
-    sta PORTB
-.endmacro
-
-proc imul8xe_init
-
-    ; go through the input set, in four 16KB chunks
-
-    arg1 = FR1
-    arg2 = FR2
-    result = FR0
-
-    lda #$00
-    sta arg1
-    sta arg2
-
-    ; $00 * $00 -> $3f * $ff
-    bank_switch 0
-    jsr imul8xe_init_section
-
-    ; $40 * $00 -> $7f * $ff
-    bank_switch 1
-    jsr imul8xe_init_section
-
-    ; $80 * $00 -> $bf * $ff
-    bank_switch 2
-    jsr imul8xe_init_section
-
-    ; $c0 * $00 -> $ff * $ff
-    bank_switch 3
-    jsr imul8xe_init_section
-
-    rts
-endproc
-
-; Initialize a 16 KB chunk of the table
-; input: multipliers in temp
-; output: new multipliers in temp
-; clobbers: temp, temp2
-proc imul8xe_init_section
-    arg1 = FR1
-    arg2 = FR2
-    result = FR0
-    ptr = temp2
-
-    lda #$00
-    sta ptr
-    lda #$40
-    sta ptr + 1
-
-    ldx #0
-    ldy #0
-
-    ; outer loop: $00 -> $3f
-outer_loop:
-
-    ; reset result to 0
-    lda #0
-    sta result
-    sta result + 1
-
-    ; inner loop: $00 -> $ff
-inner_loop:
-
-    ; copy result to data set
-    lda result
-    sta (ptr),y
-    lda result + 1
-    sta (ptr),y
-
-    ; result += 2 * arg2
-    clc
-    lda arg2
-    adc result
-    sta result
-    lda #0
-    adc result + 1
-    sta result
-    lda arg2
-    adc result
-    sta result
-    lda #0
-    adc result + 1
-    sta result
-
-    ; inner loop check
-    inc arg1
-    inc arg1
-    inc ptr
-    inc ptr
-    bne inner_loop
-
-    ; outer loop check
-    inc arg2
-    inc ptr + 1
-    lda ptr + 1
-    cmp #$40
-    bne outer_loop
-
-    rts
-
-endproc
diff --git a/mandel.s b/mandel.s
index d198989..3622995 100644
--- a/mandel.s
+++ b/mandel.s
@@ -74,9 +74,6 @@ width = 160
 half_width = width >> 1
 stride = width >> 2
 
-EXTENDED_RAM = $4000 ; 16KiB bank on the XE
-PORTB  = $D301 ; memory & bank-switch for XL/XE
-
 DMACTL = $D400
 DLISTL = $D402
 DLISTH = $D403
@@ -347,6 +344,14 @@ fill_masks:
     neg 4, arg
 .endmacro
 
+; 518 - 828 cyc
+.macro imul16 dest, arg1, arg2
+    copy16 FR0, arg1  ; 12 cyc
+    copy16 FR1, arg2  ; 12 cyc
+    jsr imul16_func   ; 470-780 cyc
+    copy32 dest, FR2  ; 24 cyc
+.endmacro
+
 .macro shift_round_16 arg, shift
     .repeat shift
         shl32 arg
@@ -357,7 +362,7 @@ fill_masks:
 .macro imul16_round dest, arg1, arg2, shift
     copy16 FR0, arg1  ; 12 cyc
     copy16 FR1, arg2  ; 12 cyc
-    jsr imul16_func   ; ? cyc
+    jsr imul16_func   ; 470-780 cyc
     shift_round_16 FR2, shift
     copy16 dest, FR2 + 2  ; 12 cyc
 .endmacro
@@ -367,259 +372,54 @@ fill_masks:
     .local under256
     .local next
     .local small_product
-    ; circa 92 cycles? this doesn't seem right
-    ; 81-92 cycles
     .scope
         mul_factor_a   = arg1
         mul_factor_x   = arg2
         mul_product_lo = dest
         mul_product_hi = dest + 1
 
-        lda mul_factor_a      ; 3 cyc
+        lda mul_factor_a      ; setup: 6 cycles
+        ;ldx mul_factor_x
 
-        ; (a + x)^2/2
-        clc                   ; 2 cyc         
-        adc mul_factor_x      ; 3 cyc
-        tax                   ; 2 cyc
-        bcc under256          ; 2 cyc
-        lda mul_hibyte512,x   ; 4 cyc
-        bcs next              ; 2 cyc
+        clc                   ; (a + x)^2/2: 23 cycles
+        adc mul_factor_x
+        tax
+        bcc under256
+        lda mul_hibyte512,x
+        bcs next
     under256:
-        lda mul_hibyte256,x   ; 4 cyc
-        sec                   ; 2 cyc
+        lda mul_hibyte256,x
+        sec
     next:
-        sta mul_product_hi    ; 3 cyc
-        lda mul_lobyte256,x   ; 4 cyc
+        sta mul_product_hi
+        lda mul_lobyte256,x
 
-        ; - a^2/2
-        ldx mul_factor_a      ; 3 cyc
-        sbc mul_lobyte256,x   ; 4 cyc
-        sta mul_product_lo    ; 3 cyc
-        lda mul_product_hi    ; 3 cyc
-        sbc mul_hibyte256,x   ; 4 cyc
-        sta mul_product_hi    ; 3 cyc
+        ldx mul_factor_a      ; - a^2/2: 20 cycles
+        sbc mul_lobyte256,x
+        sta mul_product_lo
+        lda mul_product_hi
+        sbc mul_hibyte256,x
+        sta mul_product_hi
 
-        ; + x & a & 1:
-        ; (this is a kludge to correct a
-        ; roundoff error that makes odd * odd too low)
-        ldx mul_factor_x      ; 3 cyc
-        txa                   ; 2 cyc
-        and mul_factor_a      ; 3 cyc
-        and #1                ; 2 cyc
+        ldx mul_factor_x      ; + x & a & 1: 22 cycles
+        txa                   ; (this is a kludge to correct a
+        and mul_factor_a      ; roundoff error that makes odd * odd too low)
+        and #1
 
-        clc                   ; 2 cyc
-        adc mul_product_lo    ; 3 cyc
-        bcc small_product     ; 2 cyc
-        inc mul_product_hi    ; 5 cyc
-
-        ; - x^2/2
+        clc
+        adc mul_product_lo
+        bcc small_product
+        inc mul_product_hi
     small_product:
-        sec                   ; 2 cyc
-        sbc mul_lobyte256,x   ; 4 cyc
-        sta mul_product_lo    ; 3 cyc
-        lda mul_product_hi    ; 3 cyc
-        sbc mul_hibyte256,x   ; 4 cyc
-        sta mul_product_hi    ; 3 cyc
+        sec                   ; - x^2/2: 25 cycles
+        sbc mul_lobyte256,x
+        sta mul_product_lo
+        lda mul_product_hi
+        sbc mul_hibyte256,x
+        sta mul_product_hi
     .endscope
 .endmacro
 
-; lookup table for top byte -> PORTB value for bank-switch
-;.align 256 ; warning - if not aligned this will cost an extra cycle sometimes
-bank_switch_table:
-    .repeat 256, i
-        .byte ((i & $c0) >> 4) | $e1
-    .endrepeat
-
-.macro bank_switch bank
-    lda #((bank << 2) | $e1)
-    sta PORTB
-.endmacro
-
-
-; 58-77 cycles
-; clobbers x, y, dest to dest + 3
-.macro imul8xe dest, arg1, arg2
-.local done
-.local output
-.local ptr
-
-    output = dest
-    ptr = dest + 2 ; scratch space assumed
-
-    ; bottom 14 bits except the LSB are the per-bank table index
-    ; add $4000 for the bank pointer
-    lda arg1     ; 3 cyc
-    and #$fe     ; 2 cyc
-    sta ptr      ; 3 cyc
-    lda arg2     ; 3 cyc
-    and #$3f     ; 2 cyc
-    clc          ; 2 cyc
-    adc #$40     ; 2 cyc
-    sta ptr + 1  ; 3 cyc
-    
-    ; top 2 bits are the table bank selector
-    ldx arg2                ; 3 cyc
-    lda bank_switch_table,x ; 4 cyc
-    sta PORTB               ; 4 cyc
-
-
-    ; copy the entry into output
-    ldy #0       ; 2 cyc
-    lda (ptr),y  ; 5 cyc
-    sta output   ; 3 cyc
-    iny          ; 2 cyc
-    lda (ptr),y  ; 5 cyc
-    sta output+1 ; 3 cyc
-
-    ; note: we are not restoring memory to save 6 cycles!
-    ; this means those 16kb have to be switched back to base RAM
-    ; if we need to use them anywhere else
-    ;;; restore memory
-    ;;lda #$81     ; 2 cyc - disabled
-    ;;sta PORTB    ; 4 cyc - disabled
-
-    ; check that 1 bit we skipped to fit into space
-    lda arg1     ; 3 cyc
-    and #1       ; 2 cyc
-    beq done     ; 2 cyc
-
-    ; add the second param one last time for the skipped bit
-    clc          ; 2 cyc
-    lda arg2     ; 3 cyc
-    adc output   ; 3 cyc
-    sta output   ; 3 cyc
-    lda #0       ; 2 cyc
-    adc output+1 ; 3 cyc
-    sta output+1 ; 3 cyc
-
-done:
-.endmacro
-
-.proc imul8xe_init
-
-    bank_switch 0
-    lda #0
-    sta EXTENDED_RAM
-    bank_switch 1
-    lda #1
-    sta EXTENDED_RAM
-    bank_switch 0
-    lda EXTENDED_RAM
-    beq init
-
-    ; no bank switching available, we just overwrite the value in base ram
-    rts
-
-init:
-
-    ; patch imul16_func into a forwarding thunk to imul16xe_func
-    lda #$4c ; 'jmp' opcode
-    sta imul16_func
-    lda #.lobyte(imul16xe_func)
-    sta imul16_func + 1
-    lda #.hibyte(imul16xe_func)
-    sta imul16_func + 2
-
-    ; create the lookup table
-    ; go through the input set, in four 16KB chunks
-
-    arg1 = FR1
-    arg2 = FR2
-    result = FR0
-
-    lda #$00
-    sta arg1
-    sta arg2
-
-    ; $00 * $00 -> $3f * $ff
-    bank_switch 0
-    jsr imul8xe_init_section
-
-    ; $40 * $00 -> $7f * $ff
-    bank_switch 1
-    jsr imul8xe_init_section
-
-    ; $80 * $00 -> $bf * $ff
-    bank_switch 2
-    jsr imul8xe_init_section
-
-    ; $c0 * $00 -> $ff * $ff
-    bank_switch 3
-    jsr imul8xe_init_section
-
-    rts
-.endproc
-
-; Initialize a 16 KB chunk of the table
-; input: multipliers in temp
-; output: new multipliers in temp
-; clobbers: temp, temp2
-.proc imul8xe_init_section
-    arg1 = FR1
-    arg2 = FR2
-    result = FR0
-    ptr = temp2
-
-    lda #$00
-    sta ptr
-    lda #$40
-    sta ptr + 1
-
-    ldy #0
-
-    ; outer loop: $00 -> $3f
-outer_loop:
-
-    ; reset result to 0
-    lda #0
-    sta result
-    sta result + 1
-
-    ; inner loop: $00 -> $ff
-inner_loop:
-
-    ; copy result to data set
-    lda result
-    sta (ptr),y
-    lda result + 1
-    iny
-    sta (ptr),y
-    dey
-
-    ; result += 2 * arg2
-    clc
-    lda arg2
-    adc result
-    sta result
-    lda #0
-    adc result + 1
-    sta result + 1
-    clc
-    lda arg2
-    adc result
-    sta result
-    lda #0
-    adc result + 1
-    sta result + 1
-
-    ; inner loop check
-    inc arg1
-    inc arg1
-    inc ptr
-    inc ptr
-    bne inner_loop
-
-    ; outer loop check
-    inc arg2
-    inc ptr + 1
-    lda ptr + 1
-    cmp #$80
-    bne outer_loop
-
-    rts
-
-.endproc
-
 .proc imul16_func
     arg1 = FR0   ; 16-bit arg (clobbered)
     arg2 = FR1   ; 16-bit arg (clobbered)
@@ -661,47 +461,6 @@ arg2_pos:
     rts ; 6 cyc
 .endproc
 
-.proc imul16xe_func
-    arg1 = FR0   ; 16-bit arg (clobbered)
-    arg2 = FR1   ; 16-bit arg (clobbered)
-    result = FR2 ; 32-bit result
-    inter = temp2
-
-    ; h1l1 * h2l2
-    ; (h1*256 + l1) * (h2*256 + l2)
-    ; h1*256*(h2*256 + l2) + l1*(h2*256 + l2)
-    ; h1*h2*256*256 + h1*l2*256 + h2*l1*256 + l1*l2
-
-    imul8xe result, arg1, arg2
-    lda #0
-    sta result + 2
-    sta result + 3
-
-    imul8xe inter, arg1 + 1, arg2
-    add16 result + 1, result + 1, inter
-    add_carry result + 3
-
-    imul8xe inter, arg1, arg2 + 1
-    add16 result + 1, result + 1, inter
-    add_carry result + 3
-
-    imul8xe inter, arg1 + 1, arg2 + 1
-    add16 result + 2, result + 2, inter
-
-    ; In case of negative inputs, adjust high word
-    ; https://stackoverflow.com/a/28827013
-    lda arg1 + 1
-    bpl arg1_pos
-    sub16 result + 2, result + 2, arg2
-arg1_pos:
-    lda arg2 + 1
-    bpl arg2_pos
-    sub16 result + 2, result + 2, arg1
-arg2_pos:
-
-    rts ; 6 cyc
-.endproc
-
 .macro round16 arg
     ; Round top 16 bits of 32-bit fixed-point number in-place
     .local increment
@@ -1207,8 +966,6 @@ zero_byte_loop:
 
 .proc start
 
-    jsr imul8xe_init
-
     ; ox = 0; oy = 0; zoom = 0
     ; count_frames = 0; count_pixels = 0
     lda #0