IBM 62X0776 switches

[SunDown79]

Does anyone know what the 4 switches are for on a 62X0776 MFM controller card ?
I had a look through my IBM hardware book but it isn't in there

Did find a similar card where the switches just select what kind of harddisks are connected to the card.

 

[modem7]

Xebec/IBM 62X0776

Xebec/IBM 62X0776

Switches 1 & 2 configure drive 0 (C
Switches 3 & 4 configure drive 1 (D

0 0 = Type 13 (e.g. WD25)
0 1 = Type 2 (e.g. ST-225)
1 0 = Type 16
1 1 = Type 1 (e.g. ST-412)

Source: Upgrading & Repairing PC's (Mueller), 5th Edition, page 763

 

[SunDown79]

Thanks, so its the same as in my service manual.
Was hoping it would contain some magic function but it doesn't
Am looking to get a MFM controller into a Commodore PC20-III (which already has an onboard XT-IDE interface which probably doesn't like the MFM card).

 

[monoxrom]

Please help me! I'm have IBM XT too, My HDD can't starting on IBM XT. Fdisk says "error reading fixed disk"

But other computer (386) format this drive on 10 mb. very good (as type "1" on bios) Also i was transfer system on that drive and 386 boot from that HDD good. What the problem?

HDD and wires are good, means the controller?
Remember first time he found that HDD as HDD on 20 megabutes, but only 10 present on ST-412 HDD, and i could format only 50% HDD But now controller don't want to work with HDD

I found "modem7" jumper settings, but they can't help me? and what is:
( 1 0 = Type 16 ) that meens no HDD ?

 

[modem7]

Please help me! I'm have IBM XT too, My HDD can't starting on IBM XT. Fdisk says "error reading fixed disk"
But other computer (386) format this drive on 10 mb. very good (as type "1" on bios) Also i was transfer system on that drive and 386 boot from that HDD good. What the problem?

The controller in the 386 and the controller in the XT are probably using a different low-level format.
Have you tried to perform a low-level format of the HDD when it is in the XT?

Step 1: low-level format
Step 2: FDISK
Step 3: FORMAT

HDD and wires are good, means the controller?

Is the drive an ST-412 (you do not actually say so).
What is the HDD controller in your IBM XT? A photo is good. Is it the same as eBay item 140309982308?

I found "modem7" jumper settings, but they can't help me? and what is:
( 1 0 = Type 16 ) that meens no HDD ?

XTs can be fitted with different makes and models of HDD controllers. Those switch settings are for a particular make/model of controller - the IBM/Xebec controller that has switches.

0 = off
1 = on

And so if you have that controller, and you have an ST-412, set switches 1 and 2 on the controller to 'on'.

 

[monoxrom]

The controller in the 386 and the controller in the XT are probably using a different low-level format.
Have you tried to perform a low-level format of the HDD when it is in the XT?

maybe, but i don't tried low-level format on XT, how i can start it?

debug.com
g=c800:5

Is the drive an ST-412 (you do not actually say so).
What is the HDD controller in your IBM XT? A photo is good. Is it the same as eBay item 140309982308?

Yes, HDD is ST-412/ And yes, controller it the same as eBay item 140309982308

And so if you have that controller, and you have an ST-412, set switches 1 and 2 on the controller to 'on'.

ok, but another two? 3 an 4, turn it off ?

 

[modem7]

Yes, HDD is ST-412/ And yes, controller it the same as eBay item 140309982308

Good. The drive and controller are probably the ones fitted to the computer by IBM.

ok, but another two? 3 an 4, turn it off ?

3 and 4 only need to be set if you have a second drive on the cable.

maybe, but i don't tried low-level format on XT, how i can start it?
debug.com
g=c800:5

The g=c800:x method does not work on this controller.
You'll need the Advanced Diagnostics Disk for the IBM XT, or a third-party hard drive utility such as SpeedStor.

I use SpeedStor myself on my IBM XT which has the same IBM/Xebec controller and ST-412 as you have.
SpeedStor 6.03 is available from http://members.dodo.com.au/~slappanel555/software.htm
On running SpeedStor, choose 'ManualSetup', specify Seagate ST-412, then 'Initialize' then 'StandardInit'.

A few things to check for your single drive installation:
1. On the controller, the data cable plugs into J2, not J3.
2. There is no 'cross-over' (twist) in the control cable to the drive (the wider of the two cables).
2. On the ST-412, there needs to be terminator marked "T-RES" (as shown below)
3. The shunt block should be as shown below.

 

[monoxrom]

Thank you modem7! All ok! today i can boot from HDD!

This program (SpeedStor) is very cool!

And i think this program help me with that soviet clone of XT computer:
http://www.retro-pc.net/musei/comp/ec1841/index_ua.htm
It has the same problem. HDD present but Fdisk says "error reading fixed disk"