How I created 5,25" boot diskettes (really 3.5") for my BigBoard II

Prerequisites:
Install z80pack: http://www.autometer.de/unix4fun/z80pack/ftp/z80pack-1.32.tgz
Install Linux cpmtools:
Install Linux libdsk:
Install IMD on suitable old PC. I used FreeDOS booted from an USB stick. This step was needed as my Linux box is virtual.

Grab the BigBoard CBIOS source files from here: 
http://bitsavers.informatik.uni-stuttgart.de/bits/Ferguson/Big_Board_II/bigboard_II_disks/cbios.s1/files/
http://bitsavers.informatik.uni-stuttgart.de/bits/Ferguson/Big_Board_II/bigboard_II_disks/ddboot.s2/files/

Put files in a suitable directory.
Edit DS60EA.MAC, preferebly on an editor that preserves line endings
Change:
FIVE	EQU	FALSE
EIGHT	EQU	TRUE		;SELECT 8 INCH FLOPPYS
To:
FIVE	EQU	TRUE
EIGHT	EQU	FALSE		;UNSELECT 8 INCH FLOPPYS

It might also be a good idea to change one character in the top comments and also the signon message.
This is so that you can make sure that you really have the correct file :)

Copy all *.MAC files to linux
Prepare an empty disk image. In z80pack all disks are really just raw files. You can copy an existing one and
mount it, then delete, or use cpmrm.

Copy all the .MAC files to that image, using cpmcp, ie:
cpmrm -T raw disks/library/test.dsk  0:DS60EA.MAC
cpmrm -T raw disks/library/test.dsk  0:DEBLOCK.MAC
cpmcp -T raw disks/library/test.dsk /root/cpmutils/images/BB2CBIOS/DS60EA.MAC 0:DS60EA.MAC
cpmcp -T raw disks/library/test.dsk /root/cpmutils/images/BB2CBIOS/DEBLOCK.MAC 0:DEBLOCK.MAC
(You might want to put this into a shellscript)

In addition to the sources, you need a "virgin CPM60.COM". For some reason, the on on the BBII disk above is no good.
I used this one:http://www.retroarchive.org/maslin/disks/bigboard/60k-cpm.zip

File is called CPM60.CPM, rename to CPM60.COM. I am told that 22DISK renames .COM files to .CPM. Presumably that disk was extracted with 22DISK.

You should now have a disk image with *.MAC and CPM60.COM. Make a backup copy.

Start z80pack
64K CP/M Vers. 2.2 (Z80 CBIOS V1.2 for Z80SIM, Copyright 1988-2007 by Udo Munk)

A>c:
C>dir
C: BB2FORMT CPM : BBCPM    COM : BIOS     DOC : CPM60K   COM
C: DEBLOCK  MAC : SS60EA   MAC : SS60EA   PRN : SS60EA   REL
C: MACROS   MAC : MELDING  DOC : MEMDEF   MAC : ONESECT  MAC
C: SS60E8   HEX : SS60E8   MAC : SYSGEN   ASM :          PRN
C:          HEX : SS60EA   HEX : SYSGEN   SYM : XEBEC    MAC
C: SYSGEN   COM

Assemble the BIOS:
a:m80 DS60EA.REL,DS60EA.PRN=DS60EA
Link the BIOS:
a:slrnk ds60ea,ds60ea/h/e/a:e900

You should now have a file called DS60EA.HEX that you combine with CP/M to create a file, suitable for sysgen.

My comments in paretheses
C>a:ddt cpm60.com (load cp/m into memory)
DDT VERS 2.2
NEXT  PC
2400 0100
-d980 (this step is not necessary. I just wanted to make sure)
0980 C3 5C D7 C3 58 D7 7F 00 20 20 20 20 20 20 20 20 .\..X...
0990 20 20 20 20 20 20 20 20 43 4F 50 59 52 49 47 48         COPYRIGH
09A0 54 20 28 43 29 20 31 39 37 39 2C 20 44 49 47 49 T (C) 1979, DIGI
09B0 54 41 4C 20 52 45 53 45 41 52 43 48 20 20 00 00 TAL RESEARCH  ..
09C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

-l980 (this step is not necessary. I just wanted to make sure. CP/M should start with a jump)
  0980  JMP  D75C
  0983  JMP  D758
  0986  MOV  A,A
  0987  NOP

-m980,1f7f,4000 (Move up CP/M, making room for CBIOS)
-f100,3fff,0 (Fill up the empty spaces, where we used to go...)
-ids60ea.hex (Name our CBIOS HEX-file)
-R2000 (Read it)
NEXT  PC
2400 0000
-m4000,55ff,1200 (Move back CP/M to offset 1200)
-d1200 (this step is not necessary. I just wanted to make sure)
1200 C3 5C D7 C3 58 D7 7F 00 20 20 20 20 20 20 20 20 .\..X...
1210 20 20 20 20 20 20 20 20 43 4F 50 59 52 49 47 48         COPYRIGH
1220 54 20 28 43 29 20 31 39 37 39 2C 20 44 49 47 49 T (C) 1979, DIGI
1230 54 41 4C 20 52 45 53 45 41 52 43 48 20 20 00 00 TAL RESEARCH  ..
1240 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

-d980 (this step is not necessary. I just wanted to make sure)
0980 0D 0A 2E 2E 2E 2E 20 43 61 6C 2D 54 65 78 20 43 ...... Cal-Tex C
0990 6F 6D 70 75 74 65 72 73 20 36 30 4B 20 43 50 2F omputers 60K CP/
09A0 4D 20 76 65 72 73 69 6F 6E 20 32 2E 32 20 2E 2E M version 2.2 ..
09B0 2E 2E 0D 0A 2E 2E 2E 2E 2E 2E 2E 2E 2E 20 72 65 ............. re
09C0 6C 65 61 73 65 20 64 61 74 65 20 31 35 2D 53 65 lease date 15-Se
09D0 70 74 65 6D 62 65 72 2D 38 32 20 33 2E 2E 2E 2E ptember-82 3....
09E0 2E 2E 2E 2E 0D 0A 00 00 00 00 00 00 00 00 00 00 ................
-^C
C>save 60 bbcpm.com

You now have a file with CBIOS at 980 and CP/M at 1200. Next step would be to run sysgen, but
the emulator cannot handle the BBII disk format, so we do this elsewhere. Move this file to DOS/Windows

On windows:
bb2sysgen C:\Elektronik\cpm\images\bbimage.imd C:\Elektronik\cpm\images\BB2CBIOS\bbcpm.com C:\Elektronik\cpm\images\BB2CBIOS\bbcpm.imd

This command takes an empty IMD file that has a SD track zero with 18 sectors of 120 bytes and the rest DD, 9 sectors of 512 bytes
and puts CBIOS on track 0 and CP/M on tracks 1,2

Use IMD to write this file to a 3.5" floppy. DS/DD, tape over the "HD-hole" if all you have are HD disks!

The resulting image has an interleave (skew) of 1:1 which makes booting slow, you might want to change this to 1:5, by:

IMDU BBDSCPM.IMD BBDSCPM5.IMD IL=5




