68kMLA Classic Interface

#include <stdio.h>
#include <stdint.h>

static uint8_t hhdata[1048576];
static uint8_t hldata[1048576];
static uint8_t lhdata[1048576];
static uint8_t lldata[1048576];

int main(int argc, char *argv[])
{
    FILE *hh, *hl, *lh, *ll;
    FILE *outfile;

    hh = fopen("3.3Flash4mb_HH", "rb");
    hl = fopen("3.3Flash4mb_HL", "rb");
    lh = fopen("3.3Flash4mb_LH", "rb");
    ll = fopen("3.3Flash4mb_LL", "rb");

    outfile = fopen("3.3Flash4mb_combined", "wb");

    fread(hhdata, 1048576, 1, hh);
    fread(hldata, 1048576, 1, hl);
    fread(lhdata, 1048576, 1, lh);
    fread(lldata, 1048576, 1, ll);
    fclose(hh);
    fclose(hl);
    fclose(lh);
    fclose(ll);

    for (int i = 0; i < 1048576/2; i++)
    {
        uint32_t offset = i * 2;
        fputc(hhdata[offset + 1], outfile);
        fputc(hhdata[offset + 0], outfile);
        fputc(hldata[offset + 1], outfile);
        fputc(hldata[offset + 0], outfile);
        fputc(lhdata[offset + 1], outfile);
        fputc(lhdata[offset + 0], outfile);
        fputc(lldata[offset + 1], outfile);
        fputc(lldata[offset + 0], outfile);
    }

    fclose(outfile);
    return 0;
}

For reference, my Beige G3 Rev C ROM:
...
Note the sticker on U1 starts with 600-6711 on mine, and 600-7091 on yours, looks like a part number.

I have no Gossamer G3 to test the Rom, though. I can send one of the 10 modules to someone in Europe if interested.

Very interesting! I wrote a quick C program that can combine the interleaved chip dumps back together. Ahh, I think you just beat me to it, but I'll post this anyway.

This results in a ROM with checksum 78E842A8. There aren't any Google results for this checksum so it's possibly a previously unknown version. Looks like it is identifying itself as version 77D.45F3. @joevt might be interested in this dump based on discussions here: https://68kmla.org/bb/index.php?thr...n-1st-gen-clamshell-ibooks-model-m2453.33055/

I did verify that the checksum is good, so all 4 of your chip dumps are definitely good. Thanks for sharing! Attached is the combined ROM image created by running the program. Below is the source code:

cat 3.3Flash4mb_* | perl -0777 -nE 'for ($i = 0; $i < (4 << 20); $i++) { print substr($_, ((($i >> 1) & 3) << 20) + (($i >> 3) << 1) + (($i & 1) ^ 1), 1); }' > romcombined.bin

rev C: 077d.45f2 "Boot Gossamer 0." 78f57389 616d792ee6e2877c5c8faf30b6c56fe8
rev D: 077d.45f3 "Boot Gossamer 0." 78e842a8 da81cd01c7c743f9eb2637465182f591

	2008 my_space >pci.cachelinesize config-l!

This results in a ROM with checksum 78E842A8. There aren't any Google results for this checksum so it's possibly a previously unknown version. Looks like it is identifying itself as version 77D.45F3.

From an internal document I have, 4.5F3 is "Gossamer Speedbump"

How can you tell that it identifies as 45F3?

I wonder if it relates to the rumoured (but never released) 366MHz Beige G3 - although odd they would need a new ROM revision for that. I’m not sure even what changed between Rev B and C.

I think there are some timing values in the MPC106 and a few other things that would need to be adjusted. Also potentially the 366 MHz would have had a newer/faster ATI chip.

Differences from the developer note:
- Rev A is a Rage II+DVD, Rev B & C are Rage Pro
- Rev B supports both master and slave ATA devices and the ATAPI Zip drive (Rev A only supports a SCSI Zip drive)
- Rev B adds "improved support for PCI multifunction cards"
- Rev B lets desktop and tower cases have "the same enhanced Apple Audio/Video and Audio input/output card as the All-In-One"
- Rev C machines can be configured with a DVD drive and DVD audio/video decoder card