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

[Jules Richardson]

On 9/8/20 6:04 PM, Fred Cisin via cctalk wrote:
> Date and time of Command.com and any other DOS files will identify the 
> version number.

I've got 11/26/85 on command.com.

> DIR /A  or
> DIR /A:H
> will let you see the hidden files (presumably IO.SYS and MSDOS.SYS; PC-DOS 
> had IBMBIO.COM and IBMDOS.COM instead)

The /a switch isn't part of the dir command in whatever 3.3 version I have. 
However, I just wrote a DOS 6.22 boot disk and that shows three hidden 
files on the hard disk:

   MSDOS.SYS (11/18/85)
   MIO.SYS   (11/18/85)
   SD.INI

I'm guessing that the 'M' in MIO.SYS is "Mitsubishi" and the OS is tailored 
in some way to the machine.

TYPEing "sd.ini" indicates that it's related to Norton Speed Disk - not a 
program I'm familiar with, but as that appears to be a defragmenter, it 
might hint at why my drive isn't bootable and seems to be having problems 
with various executables - I wonder if the directory structure "looks 
sane", but file contents have been completely mangled.

> Can you COPY files from the HDD to floppy?

Just filling up a few 360K disks with files at random so far, yes. But 
difficult to say if the file contents are correct.

>> Looking at the drive contents, incidentally, I didn't see anything that 
>> explains (or interacts with) that unusual video hardware - it basically 
>> just holds DOS and a bunch of documents written by the original owner. 
>> Maybe they got suckered into buying this fancy graphics hardware without 
>> having any actual need for it, and then of course EGA and VGA came along 
>> and rendered it obsolete anyway.
> 
> It is probably completely CGA compatible, unless you invoke of of its other 
> modes.

Maybe. Assuming that the hard drive's directory contents are intact, and 
therefore there's nothing too unusual on the drive, I've perhaps got 
nothing to lose by reformatting - the only issue is that MIO.SYS, how it 
differs from Microsoft's, whether it's corrupt or not, and how - if it is 
intact - I can migrate it over post-install.

Of course maybe speed disk (if that is even the cause of my problems) has 
some kind of backup / undo aspect, but I doubt it.