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RMS 518 harddisk, technical data

Roland Huisman

Veteran Member
Mar 24, 2011
The Netherlands
Well let's ask the MS-DOS guys too :D

Does anyone know the RMS 518 Hard disk? It is a 5.25 Full Height
MFM drive. So they might be used in MS-dos systems also.
I need to find a similar hard disk. But I do not now the technical data.


With a little help from Fred Jan I've got some other RMS disk data.

Disk format (H CYL S)
RMS 503 => 2 153 17 2.6MB
RMS 506 => 4 153 17 5.2MB
RMS 512 => 8 153 17 10.4MB
RMS 514 => 4 338 17 11.5MB

All these drives are 17 sector drives.

The Xebec controller is jumpered to 256 Byte / 32 sector according the Xebec documentation.
I wonder, is the drive "misused" with a slightly different data amount per track?
(It that possible anyway?) Or is it really a 32 sector drive?

Counting protection wires and diodes tells me it's probably an 8 head drive.
But still I have no clue about further technical data.
I really wonder is anyone knows this disk...

Thanks in advance!

Regards, Roland

Same question at CP/M treath: http://www.vintage-computer.com/vcforum/showthread.php?36431-Identify-harddisk-and-controller
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