Help with srecord for splitting and joining ROMs

I'd like to get the hang of joining and splitting Macintosh ROMs and have been recommended srecord by the forum regulars, but I'm having some trouble with interleaving.

I have installed srecord 1.65 on my Mac via Homebrew.

As an experiment I'm trying to combine the High and Low ROMs that I dumped from my PowerBook 1400 (I had the chips out, and used a T48 to read them).

Here's the first four longwords of the Low ROM:
50192A00 FA4EFA4E F3320000 1600FA4E

Here's the first four longwords of the High ROM:
A2830000 7D076800 64000000 4E00D04E

And here's the expected code when the ROMS are correctly combined
83A21950 0000002A 077D4EFA 00684EFA 006432F3 00000000 004E0016 4ED04EFA

The command I'm using in srecord is
srec_cat -o 341S0203-4_srec.bin -binary 341S0203-Low.bin -binary -unsplit 2 0 341S0204-High.bin -binary -unsplit 2 1

But the output is
50A21983 2A000000 FA7D4E07 FA684E00 F3643200 00000000 164E0000 FAD04E4E

I tried going the other way, i.e. taking the combined ROM and trying to split it with the following command:
srec_cat 1996-10_83A21950_PowerBook_1400_1400cs.bin -binary -split 2 0 -o Low_srec.bin -binary
srec_cat 1996-10_83A21950_PowerBook_1400_1400cs.bin -binary -split 2 1 -o High_srec.bin -binary

I get the following:
Low:
83190000 074E004E 00320000 00004E4E
High:
A250002A 7DFA68FA 64F30000 4E16D0FA

I'm at a bit of a loss here, so any help would be appreciated. I'm basically using the same commands as everyone else is using so not sure where I've gone wrong.

Attached are the high and low rom dumps as well as the correctly combined ROM (as found on Macintosh Repository and Macintosh Garden).
 

Attachments

Last edited:
Can you just try using Dos ?

Copy / B Highrom.bin + Lowrom.Bin HighLowrom.bin

Not really as I don't have access to a PC at the moment. And I'd rather figure out the problem than avoid it, since I'm told srec is the best tool to use (although not the easiest to get the hang of).
 
Back
Top