AW: CGA card (Mitsubishi Electric) with 192K RAM?

Fred Cisin cisin at
Mon Sep 7 13:17:57 CDT 2020

BTW, XT compatibles with the Xebec (and Xebec-like) hard disk controllers 
would not give a "COMMAND ERROR" message for a Low-level-formatted/wiped 
hard disk.   Probably a "1701" error.

NOTE: for the 5170 (AT), IBM switched from the Xebec controller to a 
Western Digital one.

There were many models of Xebec controller, and numerous other brands.
The specific model Xebec that IBM used had 4 pairs of solder pads near the 
center of the board for selecting drive type for 2 drives.  all open was 
10MB.  other supported sizes (could be over-ridden by loading software at 
boot) were 5MB, 16M and 26MB?

And, even if it were somehow "compatible" with a completely different hard 
disk controller, "COMMAND ERROR" doesn't sound like anybody's error 
message for a wiped drive.  More likely to be a generic "READ ERROR"
If DOS were booted from floppy, the MS-DOS error message for a wiped HDD 
(address mark not found) would be "General Failure"

Grumpy Ol' Fred     		cisin at

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