Nah for this don't waste your time with phash to be honest. There isn't a guarrentee that it will backup the whole chip and there is always a risk you could mess up the bios by inadvertently writing to it (unless its a one time write like mine is).

Using an external eprom reader means you can extract exactly what is on the bios chip and make changes and test. E.g. I killed video out in one experiment.. . So it was helpful to be able to write a new eprom.

While it adds costs, its handy to have in the toolkit anyway

Hey I just found out something that might interest you, even though it's a bit late. It's only of use to people dealing with the CT65548 where we have the full set of BMP tools available. Right now I'm playing about with a Zenith Z-note GT where I've exchanged the panel and am trying to figure out why it's ~3 lines lower than it should be. IT'd be nice if I can figure out why the scaling can be really weird on this screen as well, unlike Toshiba laptops that squish things vertically, this one squishes 320x200 horizontally while filling the vertical space, doesn't look great.

I've been struggling trying to get a VGA BIOS that the BMP tool will read on Toshiba laptops to compare with, finally found out how it's done:

Use the ramlargp.exe or ram548p.exe with this syntax:

bmp548p.exe ram548p.exe
- use this for 32KB size BIOS, I think most SBCs will use this size. Has the BMP548 utility read the contents of the VGA BIOS in place of a .rom/.bin file

bmplargp.exe ramlargp.exe
- use this for 40KB size BIOS, usually used by laptops which have a number of panel types that are selected by the main BIOS while running, usually based on some inputs like DIP switches or cables that connect some pins to GND to determine the panel type connected

- the result is that the BMP utility will read the VGA BIOS in a clean un-modified form from the BIOS data. It seems to do this using a matching .map file
- then this can be saved as a vgabios.bin file

I'd be interested to see if that gets you a file that's readable in BMP or not 😀

edit the next day: Eh, I'm not sure this works much better than pulling the VGA BIOS out of a ROM, it'll silently fail and make a default VBIOS if it can't make sense of the data it seems. So it works on my Zenith Z-note GT which I Think is a PCI 65548, but it fails on my VL-bus 65548 Toshiba.
Now I'm thinking that perhaps there are two versions of BMP548 and the BMP548P.exe that I've been able to find is PCI specific.

Thermalwrong wrote on 2023-06-22, 18:02:

Hey I just found out something that might interest you, even though it's a bit late. It's only of use to people dealing with the […]
Show full quote

Hey I just found out something that might interest you, even though it's a bit late. It's only of use to people dealing with the CT65548 where we have the full set of BMP tools available. Right now I'm playing about with a Zenith Z-note GT where I've exchanged the panel and am trying to figure out why it's ~3 lines lower than it should be. IT'd be nice if I can figure out why the scaling can be really weird on this screen as well, unlike Toshiba laptops that squish things vertically, this one squishes 320x200 horizontally while filling the vertical space, doesn't look great.

I've been struggling trying to get a VGA BIOS that the BMP tool will read on Toshiba laptops to compare with, finally found out how it's done:

Use the ramlargp.exe or ram548p.exe with this syntax:

bmp548p.exe ram548p.exe
- use this for 32KB size BIOS, I think most SBCs will use this size. Has the BMP548 utility read the contents of the VGA BIOS in place of a .rom/.bin file

bmplargp.exe ramlargp.exe
- use this for 40KB size BIOS, usually used by laptops which have a number of panel types that are selected by the main BIOS while running, usually based on some inputs like DIP switches or cables that connect some pins to GND to determine the panel type connected

- the result is that the BMP utility will read the VGA BIOS in a clean un-modified form from the BIOS data. It seems to do this using a matching .map file
- then this can be saved as a vgabios.bin file

I'd be interested to see if that gets you a file that's readable in BMP or not 😀

Very good info! Thanks for figuring this out!

I wish that utility would work with the chips 69000. Im trying to figure out a panel issue on my dauphin orasis, which has the C&T 69000 but that utility refuses to run.

What I need to do is test out different panel setting on the orasis, but becuase the chipset is newer, the ram548p utility refuses to run. The chipsets are register compatible.

I think the BMP548 and RAM548 are specific to the CT65548's BIOS structure, it won't work with the CT65550 or anything later - I just tried that accidentally earlier today by picking a Toshiba 430CDT (CT65550) instead of a 65548 equipped toshiba.

I'm not aware of any such utilities for the later chips. It's only because some industrial SBCs used the 65548 & 65550 and shared the utilities, probably mostly accidentally.
What's the issue you've got with the orasis tablet? There doesn't seem to be much information for its specs, looks like a 640x480 or 800x600 screen?
I assume it's now got a different type of screen than what the BIOS is trying to run?

Interesting - Im surprised the bios structure would be that different given the hardware revisions weren't huge leaps from what I recall (and given the ic pin outs are similar) - I could be horribly wrong on this tho.

While the tool maybe limited, if someone is brave enough to map out some more of the options/settings from various versions of the tool and how they look in the bin /output file (ie changing one at a time / scripting it etc) it might be possible to use that to decode parts of the bin/ bios of other similar models too - ie this would enable others to make changes directly on the bios file at specific addresses, then manually update the checksum burn new bios rom.

Food for thought.

Thermalwrong wrote on 2023-06-22, 20:29:

I think the BMP548 and RAM548 are specific to the CT65548's BIOS structure, it won't work with the CT65550 or anything later - I […]
Show full quote

I think the BMP548 and RAM548 are specific to the CT65548's BIOS structure, it won't work with the CT65550 or anything later - I just tried that accidentally earlier today by picking a Toshiba 430CDT (CT65550) instead of a 65548 equipped toshiba.

I'm not aware of any such utilities for the later chips. It's only because some industrial SBCs used the 65548 & 65550 and shared the utilities, probably mostly accidentally.
What's the issue you've got with the orasis tablet? There doesn't seem to be much information for its specs, looks like a 640x480 or 800x600 screen?
I assume it's now got a different type of screen than what the BIOS is trying to run?

So basically I lost the original bios (long story) and try as I might with the few bios dumps I have, I cannot get the panel to show anything. It powers up (the backlight) and that's it. I did have another member here who also has a orasis send me their bios file. We should have the same screen (640x480 DSTN kyocera panel model: KCS077VG2EA-A43). I tried their bios and it still doesnt show anything.

I wanted a way to bang on the 69000's registers and try a different panel or to try to get this one working.

Sev80 wrote on 2023-07-19, 20:05:

Thermalwrong wrote on 2023-06-22, 20:29:

I think the BMP548 and RAM548 are specific to the CT65548's BIOS structure, it won't work with the CT65550 or anything later - I […]
Show full quote

I think the BMP548 and RAM548 are specific to the CT65548's BIOS structure, it won't work with the CT65550 or anything later - I just tried that accidentally earlier today by picking a Toshiba 430CDT (CT65550) instead of a 65548 equipped toshiba.

I'm not aware of any such utilities for the later chips. It's only because some industrial SBCs used the 65548 & 65550 and shared the utilities, probably mostly accidentally.
What's the issue you've got with the orasis tablet? There doesn't seem to be much information for its specs, looks like a 640x480 or 800x600 screen?
I assume it's now got a different type of screen than what the BIOS is trying to run?

So basically I lost the original bios (long story) and try as I might with the few bios dumps I have, I cannot get the panel to show anything. It powers up (the backlight) and that's it. I did have another member here who also has a orasis send me their bios file. We should have the same screen (640x480 DSTN kyocera panel model: KCS077VG2EA-A43). I tried their bios and it still doesnt show anything.

I wanted a way to bang on the 69000's registers and try a different panel or to try to get this one working.

I did find a really crappy windows utility that will allow you to modify the registers but unlike bmp548 where it lets you configure specific panels, all this utility does (in windows) is let you directly edit the registers.