Sanitise code output from grep, replacing multiple whitespace after a range of characters - sed

Question

Answer: Thanks to Jerry Jeremiah I have the solution the end result is this:
grep -E '^\S{8} \S' test.lst | awk -F';' '{print substr($1,1,35)gensub("[[:space:]]+"," ","g",substr($1,36));}'
It requires having gawk installed
Original Question:
I have a file which i want to sanitise the output and then diff however i'm having problems coming up with working regex to do what i want
Basically i want to ignore the first 36 characters then after that start with the first non white space character and replace all multiple white spaces with a single space and strip and line comment off the end which starts with a ; and remove any trailing whitespace
I just cant figure out how to get a pattern that works while ignoring those first 36 characters, any time i use a capture group like (\S*([^\s]\s+))* it will only ever return the last match
This is an example of the code i'm grepping into sed:
00000000 =00A00000 z80_ram: equ $A00000 ; start of Z80 RAM
00000000 =00A000EA z80_dac3_pitch: equ $A000EA
00000000 =00A01FFD z80_dac_status: equ $A01FFD
00000000 =00A01FFF z80_dac_sample: equ $A01FFF
00000000 =00A02000 z80_ram_end: equ $A02000 ; end of non-reserved Z80 RAM
00000000 =00A10001 z80_version: equ $A10001
00000000 =00A10002 z80_port_1_data: equ $A10002
00000000 =00A10008 z80_port_1_control: equ $A10008
00000000 =00A1000A z80_port_2_control: equ $A1000A
00000000 =00A1000C z80_expansion_control: equ $A1000C
00000000 =00A11100 z80_bus_request: equ $A11100
00000000 =00A11200 z80_reset: equ $A11200
00000000 =00A04000 ym2612_a0: equ $A04000
00000000 =00A04001 ym2612_d0: equ $A04001
00000000 =00A04002 ym2612_a1: equ $A04002
00000000 =00A04003 ym2612_d1: equ $A04003
00000000 =00A14000 security_addr: equ $A14000
00000214 6600 bne.s SkipSetup ; Skip the VDP and Z80 setup code if port A, B or C is ok...?
00000216 4BFA 0000 lea SetupValues(pc),a5 ; Load setup values array address.
0000021A 4C9D 00E0 movem.w (a5)+,d5-d7
0000021E 4CDD 1F00 movem.l (a5)+,a0-a4
00000222 1029 EF01 move.b -$10FF(a1),d0 ; get hardware version (from $A10001)
00000226 0200 000F andi.b #$F,d0
0000022A 6700 beq.s SkipSecurity ; If the console has no TMSS, skip the security stuff.
0000022C 237C 5345 4741 2F00 move.l #'SEGA',$2F00(a1) ; move "SEGA" to TMSS register ($A14000)
The output I want is this:
00000000 =00A00000 z80_ram: equ $A00000
00000000 =00A000EA z80_dac3_pitch: equ $A000EA
00000000 =00A01FFD z80_dac_status: equ $A01FFD
00000000 =00A01FFF z80_dac_sample: equ $A01FFF
00000000 =00A02000 z80_ram_end: equ $A02000
00000000 =00A10001 z80_version: equ $A10001
00000000 =00A10002 z80_port_1_data: equ $A10002
00000000 =00A10008 z80_port_1_control: equ $A10008
00000000 =00A1000A z80_port_2_control: equ $A1000A
00000000 =00A1000C z80_expansion_control: equ $A1000C
00000000 =00A11100 z80_bus_request: equ $A11100
00000000 =00A11200 z80_reset: equ $A11200
00000000 =00A04000 ym2612_a0: equ $A04000
00000000 =00A04001 ym2612_d0: equ $A04001
00000000 =00A04002 ym2612_a1: equ $A04002
00000000 =00A04003 ym2612_d1: equ $A04003
00000000 =00A14000 security_addr: equ $A14000
00000214 6600 bne.s SkipSetup
00000216 4BFA 0000 lea SetupValues(pc),a5
0000021A 4C9D 00E0 movem.w (a5)+,d5-d7
0000021E 4CDD 1F00 movem.l (a5)+,a0-a4
00000222 1029 EF01 move.b -$10FF(a1),d0
00000226 0200 000F andi.b #$F,d0
0000022A 6700 beq.s SkipSecurity
0000022C 237C 5345 4741 2F00 move.l #'SEGA',$2F00(a1)

Answer 1

sed '
# Hold the line
h
# Remove 36 characters
s/.\{36\}//
# Remove comments
s/;.*//
# Remove leading spaces
s/[ ]*//
# Squeeze spaces after first word
s/\([^ ]*\) */\1 /
# Shuffle the output with holded line
G
s/\(.*\)\n\(.\{36\}\).*/\2\1/
'
Tested on repl when applied to input generates expected output.
how to get a pattern that works while ignoring those first 36 characters
First hold the line or relevant parts of the line you want to save. Then remove the parts you do not want to apply regex on, apply the regex. Then join the line with holded data and reorder them for the output.

Answer 2

You may use awk like:
awk -F';' '{a=substr($1,1,35); b=substr($1,36); gsub("[[:space:]]+"," ",b);print a b;}' file > outfile
See an online awk demo
Details
-F';' - field separator set to ;
a=substr($1,1,35) - set an a variable equal to a (1,35) char substring of Field 1
b=substr($1,36) - set a b variable equal to a (36,) char substring of Field 1
gsub("[[:space:]]+"," ",b) - replace all chunks of 1 or more whitespace chars with a single regular space char in the b variable only
print a b - print concatenated a and b variable values.