💾 Archived View for uscoffings.net › retro-computing › systems › Tandy › t › tandy5a.txt captured on 2023-03-20 at 20:35:07.
⬅️ Previous capture (2022-06-04)
-=-=-=-=-=-=-
#: 43924 S5/T1000/1400/3000/4K
18-Aug-91 02:47:00
Sb: #43345-#I Have It (Tandy 5.0)
Fm: Russell Hansberry 70314,1506
To: Horace Ory 71625,1006 (X)
Subj: Tandy 4000, 70MB disk, upgrading DOS 3.3 to DOS 5.0 with Windows 3.0
Sharing experience upgrading a Tandy 4000 with a 70MB hard disk and 8MB RAM
from Tandy DOS3.3 to MS-DOS 5.0 with Microsoft Windows 3.0. I had several
problems all relating to disk configuration. First, IBM/MS in its infinite
wisdom, decided that a BIOS should not support more than 1024 cylinders on a
disk. The 70MB disk has about 12MB beyond cylinder 1023. Tandy supplies
XHDISK.SYS to make these cylinders accessable as a separate logical drive.
Second, DOS 3.3 limits disk partitions to 32MB. Tandy supplies MLPART.SYS to
access a second partition in the lower 1024 cylinders as a separate logical
drive. Third, Windows really needs a disk cache for performance reasons.
Microsoft supplies SMARTDRV.SYS with Windows 3.0 but it contains warnings
about use with drives over 1024 cylinders or use with drivers that support
drives over 1024 cylinders.
Tandy supplies XHDISK.SYS to make cylinders above 1023 accessable as a
separate logical drive. I backed up my system because playing with drivers
is always a risk. Next I installed XHDISK.SYS in CONFIG.SYS under DOS 5.0
and booted my system. XHDISK complained about an incompatible DOS version.
I balked immediately. John Tierney, in this forum, indicated he was
successful overriding the DOS version reported to XHDISK. I can also report
that it works on my system with no side effects. Here is what to do:
Before upgrading to DOS 5.0, backup your disk. Make sure to have a plain DOS
copy of any files you may need immediately after installing DOS 5.0 then go
ahead and install the new DOS. Issue the DOS command "SETVER XHDISK.SYS
3.3". This tells DOS 5.0 to tell XHDISK that it is running under DOS 3.3 when
XHDISK asks. Now add two device drivers to CONFIG.SYS. They are SETVER and
XHDISK. SETVER must be earlier in your CONFIG.SYS file than XHDISK. Sample
lines from CONFIG.SYS follow. Change "yourpath" in each line to whatever
path leads to the designated driver.
DEVICE=C:\yourpath\SETVER.EXE
DEVICE=C:\yourpath\XHDISK.SYS
It is not necessary to go to a larger partition size. I wanted to do so. In
the interem, I used Tandy's MLPART.SYS driver using the same technique just
described for the XHDISK.SYS driver. I experienced no problems.
Changing the partition size above 32MB is done under DOS 5.0 because DOS 3.3
has the size limitaiton. You are going to destroy everything on your hard
disk, so back it up first. I would recommend cleaning the drive and making
two backups if reliability is a concern. Next, use the DOS 5.0 setup disk to
make a floppy based version of DOS 5.0 to get you up and running again later.
It doesn't hurt to test it either. Use the DIR command and record the label
of the bootable DOS partition for use later or use the LABEL command to
remove the label.
Remove all partitions from your hard disk using FDISK (you can run it from
the floppy based DOS 5.0). Remove them in reverse order (highest numbered
partition first). That is the only order that works. You will need the name
of that label you copied down earlier. Next add a new bootable DOS
partition. I let it default the size (it gives you the maximum).
Finally, boot DOS 5.0 from floppy disk and reload disk from your backups.
Windows 3.0 really needs a disk cache and the Microsoft SMARTDRV.SYS has
warnings about incompatibility with drives that have over 1024 cylinders. I
tried the Norton Utilities 5.0 NCACHE-F driver, using SETVER (see prior
replys in this thread). I took it down fast when it started acting wierd. I
tried again disabling caching for the drive that resides starting at cylinder
1024. That has worked reliably.
Now for the rest of the story. Symantek claims 5.0 is not compatible with
DOS 5.0 and I should upgrade to 6.0 (which I did). They still do not claim
compatibility with the XHDISK.SYS driver. For over 1024 cylinders they
support Disk Manager by On Track and Speed Store by Storage Dimensions.
Version 6.0 Norton NCACHE appears to work under the following restrictions.
Disable caching above 1024 cylinders AND do not access that area while the
cache is operational. I use the upper cylinders so I no longer use the
cache. XHDISK was designed for DOS 3.3 and I would like to cache the drive
and have the cache share memory with Windows. Does anyone have experience
with a better solution?
Just for completeness, here is a copy of my present MS-DOS 5.0 CONFIG.SYS:
device=c:\bin\setver.exe
device=c:\bin\himem.sys
device=c:\bin\emm386.exe noems
devicehigh=c:\bin\xhdisk.sys
devicehigh=c:\bin\ramdrive.sys 2048 512 128 /e
devicehigh=c:\bin\ansi.sys
devicehigh=c:\bin\ega.sys
REM device=c:\bin\ncache.exe /ext=1024 d: -a
devicehigh=c:\bin\mouse.sys
lastdrive=e
dos=high,umb
files=30
buffers=10
stacks=0,0
break on
shell=c:\bin\command.com c:\bin\ /e:1024 /p
Many thanks to John Tierney for blazing the trail for me.