IBM 5160 - IBM/Xebec HDD Controllers Supplied

These hard disk drive (HDD) controllers were made for IBM by the Xebec company.

The term "variation" used below is my terminology. I'm unaware of IBM nor Xebec using it to describe the variations in the controllers.

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Variation #1

This is the earliest of the three controllers shown on this page. Circa 1983 (based on chip dates).

The IBM ROM is 8K in size and stamped with IBM part number "5000059".
The ROM contains the string of "5000059 (C)COPYRIGHT IBM 1982".

This controller only supports a drive that has the following characteristics: cylinders = 306 / heads = 4 / WPC = 0 / a step rate of 70 µs is valid

IBM supplied with the controller, a Seagate ST-412 drive. Interestingly, the ST-412 matches the above characteristics except for WPC. The ST-412 has a WPC of 128. Either IBM did not consider WPC important (unlikely), or a mistake was made.

As can be seen in the photo following, this controller is normally stamped "IBM 1501492" on the component side (but note that the number 1501492 gets reused on a later controller).

Click here to see IBM's technical document for this variation of the card (contains matching circuit diagram).
Click here for a cabling information.
Click here for information about low-level formatting.

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Variation #2

This is the next variation of the controller. Circa 1984 (based on chip dates).

There are two ROMs, one Xebec and one IBM. The IBM ROM is 8K in size and stamped with IBM part number "6359121".
Although the IBM ROM has a different part number to that used in variation #1, the contents are identical.

From a user's perspective, variation #2 is simply a more modern version of variation #1. It offers no new or changed functionality.

It is important to note that this controller lacks the switch block that the later controller (variation #3) has.
It can be seen that there is a position for a switch block (S1, bottom-right corner, just above TP4), but no switch block has been soldered on.

As supplied, this controller (like variation #1) only supports a drive that has the following characteristics: cylinders = 306 / heads = 4 / WPC = 0 / a step rate of 70 µs is valid

The IBM ROM actually supports 4 different types of drives, but because of the lack of a switch block, the controller is limited to supporting the drive characteristics specified above.
If you were to add a switch block, the drive support would be as shown on this link.

Click here for a cabling information.
Click here for information about low-level formatting.

Known Part Number Variations

1. Component side: "IBM 6135983"  / Solder side: "IBM 6135984"
2. Component side: "59X7192YF" on white sticker  / Solder side: "IBM 6135984"
3. Component side: "59X7192YF" on white sticker  / Solder side: "IBM 1501492"   (the number 1501492 has been reused from the earlier controller)

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Variation #3

This is the next variation of the controller. Circa 1986 (based on chip dates).

Supported the particular 20 MB sized drives that were optionally fitted to the later model 5160s.
IBM referred to this controller as the "20MB Fixed Disk Drive Adapter" (box photo).

There are two ROMs, one Xebec and one IBM. The IBM ROM is 4K in size and stamped with IBM part number "62X0822".
The IBM ROM contains the string of "559X7291 (C) COPYRIGHT IBM CORP.,1982 ,1985.".
The IBM ROM content is different to the IBM ROM in the earlier variations.

This controller has the switch block that the earlier controller (variation #2) lacks. The switches are set according to the drive/s attached.

Click here to see IBM's technical document for this variation of the card (contains matching circuit diagram).
Click here for a cabling information.
Click here for information about low-level formatting.

Switch Settings

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

Table Address	Switch Settings for C:	Drive Characteristics	Example	Comment
0	1=on 2=on	Cylinders = 306 / Heads = 4 / SPT = 17 / WPC = 0 / a step rate of 70 µs is valid		Not IBM Type 1 - type 1 has a WPC of 128
1	1=on 2=off	Cylinders = 612 / Heads = 4 / SPT = 17 / WPC = 0 / a step rate of 70 µs is valid		In 1986, known as IBM Type 16
2	1=off 2=on	Cylinders = 615 / Heads = 4 / SPT = 17 / WPC = 300 / a step rate of 70 µs is valid	Seagate ST-225 [20MB HH]	In 1986, known as IBM Type 2
3	1=off 2=off	Cylinders = 306 / Heads = 8 / SPT = 17 / WPC = 128 / a step rate of 70 µs is valid	IBM WD25 [20MB FH]	In 1986, known as IBM Type 13

The information in the above table was sourced from the book: Upgrading and Repairing PCs, Scott Mueller, 5th Edition, page 761/762/763    (or page 387 of 1st edition)
That ties in well with the list that SpeedStor software reports.

Known Part Number Variations

1. Component side: "62X0775" on white sticker  / Solder side: "IBM 62X0776"
2. Component side: "62X0786" on white sticker  / Solder side: "IBM 62X0776"

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Xebec 1210C

The photo below is only here to show a Xebec model 1210C, of about 1986, and how very different it looks compared to the 1986 dated card that Xebec supplied to IBM.