Dont know about this specific chip, but I had the same problem. Maybe this is also helpful
Post 591527
Think it should work in your board, too.

Sorry for hijacking a thread, but has somone used that LAN card option rom, to make a ROM version of dos boot disk, i would be cool to just boot to dos with a lan card and a rom chip. I have googled, and i think it is totally possible, but have not find any exact instructions or roms.

Or even somehow put a partition boot manager inside a LAN boot rom. In a 256kb rom, you can add DOS and even some basic tools.

Cyberdyne wrote:

Sorry for hijacking a thread, but has somone used that LAN card option rom, to make a ROM version of dos boot disk, i would be cool to just boot to dos with a lan card and a rom chip. I have googled, and i think it is totally possible, but have not find any exact instructions or roms.

Or even somehow put a partition boot manager inside a LAN boot rom. In a 256kb rom, you can add DOS and even some basic tools.

The Tandy 1000 series - or at least the SL and TL - had MS-DOS 3.3 in a ROM, which was the default boot device. I bet you could do something like that, but I'm not sure how useful it'd be.

It's supposedly possible to boot from an m-systems DISK-ON-CHIP via a LAN card boot rom.

https://en.wikipedia.org/wiki/M-Systems

I tried it myself and couldn't get it to work.

u can use any [e][e]prom with matched or greater size and matched pinout.
if u use prom with greater size, than real bios size - duplicate bios two or 4 times to fully fill chip.
ie if original chip was 32 KBytes size:

1            old
2            chip
3E000EFFFF000FFFF <- end of first megabyte,
4XXXXXXXXXXXXBIOS 

then if u want use 64 KByte chip, u need make that:

1        new chip
2E000EFFFF000FFFF <- end of first megabyte,
3XXXXXXXXBIOSBIOS

So I'm going to attempt to update to a newer BIOS on a 286 I'm building up. The BIOS Chip Type is :
http://www.radiomuseum.org/tubes/tube_r4-th018.html

Never heard of that model before, sorry. 🙁
Perhaps it's just a one-time programmable EPROM chip of an eastern production ?

OTP's are essentially normal EPROMs, but without an UV window of quartz.
The "256" could hint of the size in Kilobits (256/8= 32 KB).

And since the pin count is 28, it could be likely something compatible to a 27C256.
27xxx or 27Cxxx were the de-facto standard for EPROM chips back in the day.

Reading wise, they should all behave pretty much the same.

I haven't tried yet, but some of the 28C and 29F series can be used as drop-in replacements.
Sometimes a tiny bit of re-wiring is required, but that's nothing a cheap plastic socket can't solve. 😉

Anyway, I really recommend to get a real EPROM programmer, not just a $5 BIOS flasher.
On the long run, they (real prommers) will save a lot of stress and dissappointment.

Personally, I had a good experiences with both a G550 and and TL866CS so far.
These units costs roughly about $50 (~40€) and work for most of the CMOS chips (27C???).

Edit: Oh, and let's don't forget the UV eraser. They can be bought really cheap from China.
Strangely, they seem to operate at 110/130V, though. Perhaps they are export devices for the market of the USB, dunno..
Anyway, since I'm in Europe, I have to use it with a step-down converter here.

If you go the same route, make sure you get a few 27C EPROMs also. And by different brands, if possible.
In case of doubt (or the lack of support in the programmer's database), programming these with the settings
for their "intel" or "amd" counterparts should do.

G550 is pretty much garbage, however the TL866CS is pretty good.

I have a g840 its the bomb. there are many many versions of TL866CS floating around, some not so good ones, some very good.

.legaCy wrote:

G550 is pretty much garbage, however the TL866CS is pretty good.

Um, okay. 😐 The G540 worked good enough for me, if I used a strong USB port (USB 3.x).
The control software could be better, though. The Engrish spelling isn't that good.
Gratefully, someone made a patch to fix that : 😀
http://www.pjmelect.talktalk.net/

Cyberdyne wrote:

Sorry for hijacking a thread, but has somone used that LAN card option rom, to make a ROM version of dos boot disk, i would be cool to just boot to dos with a lan card and a rom chip. I have googled, and i think it is totally possible, but have not find any exact instructions or roms.

Or even somehow put a partition boot manager inside a LAN boot rom. In a 256kb rom, you can add DOS and even some basic tools.

Maybe have a look at this post: Re: Large IDE drives on 286/AT/ISA class machines
It's not entirely what you're looking for but, might be helpful in getting around some "pitfalls".

Jo22 wrote:

Um, okay. :neutral: The G540 worked good enough for me, if I used a strong USB port (USB 3.x). The control software could be be […]
Show full quote

.legaCy wrote:

G550 is pretty much garbage, however the TL866CS is pretty good.

Um, okay. 😐 The G540 worked good enough for me, if I used a strong USB port (USB 3.x).
The control software could be better, though. The Engrish spelling isn't that good.
Gratefully, someone made a patch to fix that : 😀
http://www.pjmelect.talktalk.net/

G540 cant flasha modern spi flash from a z170 board, to be honest i didnt even found the right model to flash the bios from an asus m2n-x.
The tl866cs is way better compared to g540.

Thanks all, I've gone ahead and got the TL866CS, UV eraser and a handful of the 27C128, 27C256 & 27C512 eprom chips from ebay. That should cover all bases and give me some spares for future projects. Now just have to wait for the boat from China!

The TL866CS is fine, too. Just remember to uncheck the "Check ID" checkbox, to make the programming sequence work.
Otherwise, you'll end up like me and bang your head on a table many times. Haha. 😁

Good luck! ^^

matpro wrote:

Thanks all, I've gone ahead and got the TL866CS, UV eraser and a handful of the 27C128, 27C256 & 27C512 eprom chips from ebay. That should cover all bases and give me some spares for future projects. Now just have to wait for the boat from China!

Following the instructions that is provided here it should work like a charm.
Good luck