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 [ 5 posts ] 
 Splitting & Combining ROM images 
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Joined: Sat Aug 10, 2019 1:13 am
Posts: 7
It surprises me how little information there is online about how to split ROM images into their LO & HI bytes.
Typically with buses 16-bits and wider, multiple 8-bit ROMs are used to cover the entire width of the bus; thus requiring the firmware binary to be split into parts.
The command line tool srec_cat can be used to do what we need:
srec_cat -o LOW.bin -binary ROM.bin -binary -split 2 0
srec_cat -o HIGH.bin -binary ROM.bin -binary -split 2 0

Bonus example: Combining the LO & HI ROM dumps back into a flat binary:
srec_cat -o ROM.bin -binary LOW.bin -binary -unsplit 2 0 HIGH.bin -binary -unsplit 2 1

For a more in depth explanation, see my site entry on the topic.

Last edited by NotArtyom on Mon Apr 27, 2020 12:36 pm, edited 1 time in total.

Sat Feb 22, 2020 11:25 am WWW

Joined: Tue Dec 11, 2012 8:03 am
Posts: 285
Location: California
I've used that tool at It was a lifesaver.

_________________ lots of 6502 resources

Sat Feb 22, 2020 7:09 pm WWW

Joined: Sat Feb 02, 2013 9:40 am
Posts: 2105
Location: Canada
I wrote my own tool a while ago called "split.exe" that as tested now doesn't work in 64-bit Windows. Time to upgrade it. I suspect others have found their own means to split files.
I've also a tool called "RAMBBuster" to convert a binary file into a series of "INST_xxx" definitions for an FPGA constraints file. It can swap the byte order around in the process.
Useful for setting initial block ram contents.

Robert Finch

Sun Feb 23, 2020 3:08 am WWW

Joined: Sat Feb 02, 2013 9:40 am
Posts: 2105
Location: Canada
Updated split to Windows 64-bit and placed the source code in GitHub under the software/split folder.
split will split a file into up to eight different output binaries.

split - binary file splitting utility.
2009-2020  Robert Finch
split <filename> <option>
        Splits an input file into up to eight output files.
        <option> has two parts - a character code b,h,w,d and the number of
        output streams
        the character code indicates the output stream (file) width
        (b=byte,h=halfword (16 bits),w=word(32 bits),d=double word (64 bits)
        Example: split test.bin w4
                will treat test.bin as a series of word (32 bit) values
                and split the test.bin file into four output files (test.o0, test.o1, ...)
                from the input file.
        Input file name default extension is '.bin'.

Robert Finch

Sun Feb 23, 2020 4:13 am WWW

Joined: Mon Oct 07, 2019 2:41 am
Posts: 619
Splitting by nibbles (4 bits) might be usefull, if one had to update a machine using really old proms
say for microcode.

Mon Feb 24, 2020 6:10 pm
 [ 5 posts ] 

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