Possible to speed up I/O subsystem of 5150?

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Thu Dec 9 15:40:10 2004

On Thu, 9 Dec 2004, 9000 VAX wrote:
> There are 8 bit SCSI controllers too. Once I sold two to one guy for
> $10. Both used NCR 53c90, both had ROM and were bootable.

I have a DTC 3250 (SCSI + floppy) with manual AND DRIVER DISK!, and a
Future Domain TMC-840. Both have ROMs (EPROMs?) They are available if
they will help.
(I found them a few days ago while looking for my ST-01s (another thread);
Some book or magazine had had source code for a stand-alone CD-ROM driver
using the ST-01, and I had gotten a few to play with many years ago.)

> > SMARTDRV was bundled with Windoze 3.10, and will work with
> > some of the <3.30 DOS versions.
> > But you need to use 3.31 or newer to have any partitions
> > larger than 32M.
> XT's do not have more than 640K memory, thus SMARTDRV is not very useful.
But wouldn't a few hundred K of cache be helpful?

While it's true that XTs can not have more than 640K of REAL memory
(actually 1M minus some overhead with some hardware and software hacks),
not even HIMEM, and certainly no XMS (Extended Memory Specification),
I have had up to 8meg of "Expanded" memory on XTs.
I have a tote full of TallTree JRAM, JLASER, etc. stuff.
I don't know what the max was on the later LIM (Lotus Intel MicroSoft)
EMS (Expanded Memory Specification).

Grumpy Ol' Fred     		cisin_at_xenosoft.com
Received on Thu Dec 09 2004 - 15:40:10 GMT

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