Vintage 1986 Xebec/IBM XT 62X0786 8 - Bit MFM Hard Disk Controller, 10MB/20MB Only
Item History & Price
| Reference Number: Avaluer:7847157 | Country/Region of Manufacture: Japan |
| MPN: 62X0786 | Compatible Brand: For IBM XT & compatibles |
| Brand: IBM | Type: Controller Card |
This is the third and final hard disk controller which IBM used in their PC/XT 5160. IBM put their part numbers 62X0786 and 62X0776 on this full length 8-bit ISA card, designed by Xebec. It controls one or two hard disks only, with no floppy controller. What I find unusual is that this controller uses DIP switches to select the types of hard drive. It will ship with the switches set for one or two Seagate ST225 disks (615 cylinders, 4 heads).&...nbsp; It low level formats disks to 17 sectors per track only. The BIOS is limited to only 4 types of hard disks:
The pictures here are of the exact MFM controller you will receive. I welcome questions from interested buyers.
I will make sure that it ships securely and promptly. I offer free shipping within the U.S. and a 30 day warranty. Have fun!
Switch Settings
Switches 1 and 2 configure drive 0.
Switches 3 and 4 configure drive 1.
Table
Address Switch Settings
for drive 0 Drive Characteristics Example Comment 0 1=on 2=on Cylinders = 306 / Heads = 4 / SPT = 17 / WPC = 0 /
Not IBM Type 1 - type 1 has a WPC of 128 1 1=on 2=off Cylinders = 612 / Heads = 4 / SPT = 17 / WPC = 0 /
In 1986, known as IBM Type 16 2 1=off 2=on Cylinders = 615 / Heads = 4 / SPT = 17 / WPC = 300 /
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 /
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)
The pictures here are of the exact MFM controller you will receive. I welcome questions from interested buyers.
I will make sure that it ships securely and promptly. I offer free shipping within the U.S. and a 30 day warranty. Have fun!
Switch Settings
Switches 1 and 2 configure drive 0.
Switches 3 and 4 configure drive 1.
Table
Address Switch Settings
for drive 0 Drive Characteristics Example Comment 0 1=on 2=on Cylinders = 306 / Heads = 4 / SPT = 17 / WPC = 0 /
Not IBM Type 1 - type 1 has a WPC of 128 1 1=on 2=off Cylinders = 612 / Heads = 4 / SPT = 17 / WPC = 0 /
In 1986, known as IBM Type 16 2 1=off 2=on Cylinders = 615 / Heads = 4 / SPT = 17 / WPC = 300 /
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 /
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)
