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5160 and 5162 HDDs tables

J

jammaster

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For those who want to modifying there HDD type in your XT~XT286.
You need eprom reader/burner.

For the 5160 type 2 xebec card, here is the offsets of HDD tables:
http://theangel540.free.fr/xebec hd table.jpg

you can set HDD type by adding a dipswitch bloc on the controller card.
The graâl can help you a lot as always (minus0° ;-) )



For the 5162, you need to create a 16Bit dump by unifying the 2 dumps (u34 / u35) with winhex. (odd and even data)
the offsets are here:
http://theangel540.free.fr/5162 hd table.jpg

The first of the 23 types of HDDs is type 1 , 306 cylinders count.
It make 132 in hex... 3201 in eprom (the endianness hell ;-) )
The second is 615 cylinders.
It make 267 in hex ... 6702 in eprom.
...
...

a Very easy way when Bios where not compressed!

My XT286 work well with a cool ST-4096
 
Last edited:
Oh yes, it's a well-known procedure.
Hint: when installing an HDD in an unknown vintage PC, make sure the standard drive types are really standard, as somebody might have modified them like above.
There are programs to display the BIOS table of HDD parameters on AT machines: Speed Stor, Checkit Pro, and others.

BTW, I've got a big MFM HDD, with more than 1024 cylinders, and I want to use it in a 286.
I can access its full capacity using SSTOR.SYS, but this method is a bit ugly - requires partitioning.
Any ideas of a more elegant solution?
Modification of BIOS parameters table is not enough here, INT 13h can't into cylinders>1024, some translation is necessary.
I was thinking about using XTIDE Universal BIOS - it supports translation of C/H/S numbers, it supports generic AT IDE controllers, and AT MFM controllers aren't different than IDE from the BIOS point of view, are they?
Anybody tried something like this?
 
Some WD MFM controllers were able to use 12 bit cylinder addresses and worked the BIOS interface by appropriating the 2 high-order bits of the head register.

Still, hacking an MFM BIOS ROM with a translation routine shouldn't be that difficult.
 
Chuck(G) said:
Some WD MFM controllers were able to use 12 bit cylinder addresses and worked the BIOS interface by appropriating the 2 high-order bits of the head register.
Click to expand...
Hardware translation in a controller card? Seems great!
So, what particular controller model should I look for?
 
The best way will be to do the translation on the controller board.
The CX register is limited to 10bits for Cylinder. (with a stock system BIOS and a stock configuration of the 16bits width of the register).
A custom controller bios will translate a large virtual sector area (defined in the system bios) in a real larger cylinder value (equal to the drive specs).
But, to my mind, it's better to use the hardware available at the time for making a pure 286 machine.
It's the reason why i have put the ST4096 in my little 5162.
I admit that a Big ****.... MAXTOR MFM drive is really rock'n'roll... ^_^
 
SCSI hard drive controllers have no compunction about translating sector addresses into SCSI's LBA mode.

It really shouldn't be that difficult to hack some BIOS code. Consider that almost all MFM hard drives are spec-ed at 17 sectors/track. So a "wedge" to state 34 SPT instead, shouldn't be that difficult and doubles the cylinder range.
 
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