30 Jul
2024
30 Jul
'24
3:47 a.m.
On Mon, Jul 29, 2024 at 6:21 PM Fred Cisin via cctalk <cctalk(a)classiccmp.org>
wrote:
On Mon, 29 Jul 2024, Murray McCullough via cctalk
wrote:
The DEC Rainbow had initially a 2.01 and later 2.05 version.
I had not realized that 43 yrs. ago Microsoft
purchased 86-DOS for
$50,000
– US not Cdn. money. With this purchase the PC
industry, IBM’s version
thereof, began. I remember using it to do amazing things, moreso than
what
8-bit machines could do!
Ah, but there is so much more to the story, which deserves an entire
chapter in the history.
More than you wanted to know? : (but even more details available if you
really want them)
...
Initially MS-DOS and PC-DOS differed only in name and trivial items, such
as "IO.SYS" and "MSDOS.SYS" being renamed "IBMBIO.COM" and
"IBMDOS.COM"
When changes were made, Microsoft's and IBM's version numbers were
separated.
Thus 1.00 was the same for both
IBM released PC-DOS 1.10, and Microsoft released MS-DOS 1.25
2.00 was the same for both
2.10 VS 2.11 (IBM needed trivial changes to 2.00 to
deal with the
excessively slow Qumetrak 142 disk drives in the PC-Junior and "portable"
And then upgraded to 2.11 quickly when it was available...
3.00 was the same
3.10, adding network support and the "network redirector for CD-ROMs
Later, there was 3.10 (from Ford, semi-bootleg) and then 3.10a and 3.10b
(from suitable
solutions).... and not 3.11 and 3.12 like I'd half expected...
3.20 VS 3.21, adding "720K" 3.5" drive
support
Yea, I had to write IMPDRIVE because I could get 3.5" drives for no money,
but
not SS iDrive at the time to get this...
3.30 VS 3.31, BUT 3.31 was the first to support
larger than 32Mebibyte
drives!
I'd wished that there would have been a 3.30 Rainbow port for bigger disks,
but no
joy... But the native controllers maxed out at 67MB and the 'modded'
controllers with
one more bit for I think heads (using the next version of the WD chip)
could do 134MB....
But it was all too little too late (I've seen 2 Rainbows with this mod, not
my own alas)...
This side trip down memory lane brought to you by one motor, two disks
RX-50...
Warner