• Please review our updated Terms and Rules here

AT 286 save bios in two support EVEN/ODD on ms-dos

A

andromeda92

Experienced Member
Joined
May 6, 2020
Messages
263
Location
FRANCE
Hi,
On my 286 motherboard i have two bios, one EVEN and other ODD. (27c256)
when i save bios with nssi i have one file with size 65536
I would have two files with size 32768

how do i do ?
I have to split the file which has the size of 65536 for have two file with size 32768 ?
how do i do on ms-dos ?

I would like to make a backup because it does not exist anywhere, even on retroweb.com and other sites

Thank for your help.
 
srec_cat utility from Srecord package can do that. It will be easier to do that under Linux, although the Srecord can be also compiled under Windows.

Something like:
srec_cat -o EVEN.bin -binary BIOS.bin -binary -split 2 0
srec_cat -o ODD.bin -binary BIOS.bin -binary -split 2 1
Click to expand...

P.S. You can send the binary to me, or attach it here, and I'll gladly do that for you
 
See srec_cat from https://srecord.sourceforge.net/ it can separate and combine the binary data in a variety of ways. There are many ways to interleave multiple ROMs. So likely something like:

Code: 
# Split flat ROM into low and high
srec_cat -o LO.bin -binary FLAT.bin -binary -split 2 0
srec_cat -o HI.bin -binary FLAT.bin -binary -split 2 1
# Recombine them
srec_cat -o NEW_FLAT.bin -binary LO.bin -binary -unsplit 2 0 HI.bin -binary -unsplit 2 1
# Compare original and reconstituted
md5sum FLAT.bin NEW_FLAT.bin

To really, really, really confirm the interleaving of the ROMs, you would need to pull them and dump them with a reader. Then compare to the srec versions.
 
I did a test with an existing rom from another motherboard with the command dos split /b 32k bios.bin, it works, the two files are identical with a hex editor, but I will try the command you are talking about under linux and compare them with md5sum.

so I have to dump the roms with my eeprom programmer then after I use the srec_data command

[EDIT]
ah I don't think if I dump the 2 27c256, 'I already have the two files,
but it's easier to use the dump file by nssi or dump directly the 2 27c256 ? and use the srec_cat command?
 
Last edited:
Modem7 wrote a Windows program called OddEven, Just run OddEven.exe and point it to the dump file from NSSI and the file will be split into Odd and Even bytes, There is a link to download it on this page.
 
it's done,
I used the srec_cat command, I have two files, I rebuilt them and made an md5sum for verification and is ok, I did the same thing with the oddeven program and it is ok too.
Thanks for the explanations and the split programs.
WD286.BIO is from nssi. i can too put the two files for oddeven programm if you want.
 
attach file not work ?

[EDIT]
Bios Phoenix.
 

Attachments

  • HI.zip
    19.9 KB · Views: 5
  • LO.zip
    19.5 KB · Views: 5
  • WD286.zip
    34.2 KB · Views: 6
Last edited:
andromeda92 said:
I did a test with an existing rom from another motherboard with the command dos split /b 32k bios.bin, it works, the two files are identical with a hex editor, but I will try the command you are talking about under linux and compare them with md5sum.

so I have to dump the roms with my eeprom programmer then after I use the srec_data command

[EDIT]
ah I don't think if I dump the 2 27c256, 'I already have the two files,
but it's easier to use the dump file by nssi or dump directly the 2 27c256 ? and use the srec_cat command?
Click to expand...
I believe split is not what you want. Split would take the first 32 KiB of the input file and write them to the first output file, and then take the second 32 KiB of the input file, and write them to the second output file.
What you need is every other byte written into a separate file, that is, all bytes with even addresses go to one file, all bytes with odd addresses go to the other file

I am not sure I understand the comment about EPROM programmer. You don't need one. Just dump the content of the ROM on the system with whatever software you're using (I'd just do DOS DEBUG?!), and then split the resulting file into even/odd files.
 
yes, so that's what I did, everything is ok I attached the two files and i have used srec_cat and oddeven for verification from wd286.bio.
files with oddeven.
 

Attachments

  • WD286.BIO_EVEN.bin.zip
    19.5 KB · Views: 7
  • WD286.BIO_ODD.bin.zip
    19.9 KB · Views: 6
  • WD286.zip
    34.2 KB · Views: 5
this bios comes from my motherboard which is closest to the WD286-LPM, on the motherboard there is a label which indicates LPM 286, behind the label there is marked USIT, there are also two other motherboards which are looks like, ATHENA SMT-216LP and AT&T, INC. MODEL 6286/EL WGS (FM-0589-04). The bios is a Phoenix. 12Mhz cpu N80L286 12/s, with chipset FARADAY and video Paradise PVGA1A JK.
 
It's just that I bought this motherboard and I'm a curious person,
I like to know the possibilities of a motherboard, and I always wanted a motherboard closer to an IBM AT 286 , it brings back memories, maybe my next motherboard will be a 386, I already have a 486 dx266 desktop pc and some thinkpad laptops with pentium III, toshiba etc and an IBM5155 and some pentium II-based motherboards that I don't use. I will test some old games, and why not a turbo c or turbo pascal.
each motherboard is different and if it needs to be repaired I do what I can to make it work properly.
 
That's one of the problems with the early LSI chipset systems--they're very particular about BIOS--said BIOS often contains initialization code for the chipset. What are numbers of the WD chips on your system?
 
Well, the WD37C65xxx is the floppy controller, WD16C452 is the serial port support. The FE3021 is a DRAM controller and the FE3010 is a sort of all-in-one timer, DMA controller, interrupt controller, etc. brief description here. That same description mentions the Gridcase 1520 as one system that uses it.

Have you tried a simple no-frills 286 BIOS yet? I remember that my Faraday A-Tease motherboard would run just fine with one.
 
Have you tried a simple no-frills 286 BIOS yet? I remember that my Faraday A-Tease motherboard would run just fine with one.
Click to expand...

I don't understand this.
simple no-frills 286 BIOS yet ?
Click to expand...
the bios already existed it must be the original

This simple bios existe ? may be i can test it
 
Last edited:
Well, let's stay with the Faraday chipset. Here's an A-Tease ROM for the 6 MHz 286 board. Note that there are two 16k images--one for the even, and one for the odd. (u72 is even, u73 is odd). Note that these use 27128 ROMs, so if you're using 27256, you'll have to duplicate the image in each ROM. (If you find this confusing, others can help you out--it's been discussed many times in this forum).
 

Attachments

  • a-tease.zip
    15.2 KB · Views: 7
I have to replace these a-tease roms with those I currently have on my motherboard?
my motherboard is 12Mhz.

Eprom from my motherboard is 27C512, can I put 27c256 instead?
 
Last edited:
You must log in or register to reply here.
Back
Top