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Ibm xt 5160

VintageVic

Experienced Member
Joined
Dec 9, 2019
Messages
340
Location
Finland
So, I decided to set up this thread for this 'storage found' IBM XT 5160.

I have already discussed about the history of this unit in hard drive help request thread here:
http://www.vcfed.org/forum/showthread.php?72705-Seagate-ST-412-stuck-(spindle-not-spinning)

To avoid repeating myself, I post the link above.

But, as a summary, I got this unit some 25 years ago for less than 5$.
They were not desirable at that time at all. Back then I had no experience to
get the unit to work and I soon lost interest in it and put it into cold storage.

Now, the interest is found and unit rediscovered from the storage. Cold storage did no
good to the unit and it had many issues.

o Power supply interference caps blew at first attempt. They were replaced, and not psu is working.
o Keyboard is missing ALT key, that prevents booting. As a solution, I'm blocking the alt key down. Looking for xt keyb. alt key !
o One RAM chip at bank 3 was faulty and replaced. Total of 512kb ram was working at that time.
o Floppy drive was giving 601 error. Maybe due to stuck HD or alternatively, unplugging the controller
and cables and reinserting them, the floppy is now working well and giving no 601 error during boot.
o Seagate st-412 HD's spindle was stuck. More of how to recover this in the link above. Drive is now
working and booting reliably. However, there is some significant noise - I mean extra noise that maybe
coming from the drives bearings at times. Now that I think of it, the mounting screws are not yet in
place to the IBM chassis and some extra noise may be from vibration. Hopefully it is nothing serious and
the drive has still somewhat long life left. I have to comment, that the spindle motor has surprisingly
weak torgue, it is barely anything and the drive takes really long to get up to full speed. However, this maybe
just according to its specs :cool:
o 256kb ram card failed soon, right after I was starting to get the st-412 running up. Ram check got stuck
at 320kb. Rebooting resulted the ram check stuck at 0. I'm currently running the xt at 256kb motherboard ram only.
Perhaps there is a hint to what ram chip is busted. 320-256 = 64. It maybe chip no 8 that has failed. I recently
acquired about 100 8kb ram chips from china for the C64, so I should definitely have enough chips to fix the ram card.

I'm new with the IBM XT. Last night, I got first games transferred to the unit! And what a job that is.
The media transfer chain goes like this:

abandonware sites -> USB -> XP pc, that has USB support and 1.44 floppy -> 1.44mb floppy -> 486dx33 HD -> (change of
1.44 floppy drive to XT 360kb floppy drive) -> to the 360kb floppy itself -> to the IBM XT hard drive !

Whoa - going through this chain is really time consuming =).
I'm trying to get this chain a bit shorter, but I noticed yesterday, that connecting 5 1/4" floppy
drive to newer pc is not possible. Even if it has floppy adapter, it may support only 720 or 1.44 floppies and
not the 1.2mb or 360kb drives. That was the case with that winxp pc I have in use.

I also learned, that IBM XT original display adapter does not seem to support graphics. At least, that
adapter that I have with the green monitor. But, there was a second display adapter. I read hercules
and Video in it, so I figured out, that adapter may support graphics. Sure enough, I started the packman
game and I had to move the monitor cable from original display adapter to the Hercules adapter. I got
graphics then! But when exiting back to dos 3.3, I had to move the display cable back to the original display adapter.

-> is this really the normal standard setup ? It feels really clumsy to change the display cable when chance
happens from text to graphic states or backwards. Maybe I'm doing something wrong - I probably am :).

Well here is where I'm at with this today.
Some more work to do, tidying up to do and upgrades to do.
I have at least one 8bit VGA card, that I'm going to try with the XT. Would be much cooler
to have colors and some games require color adapter to work at all.

I'm attaching two pics from the day when I rediscovered the unit from cold storage.
With it, there was Mikromikko 3TT (supposed to have been upgraded to 386) and IBM ps2/model 30.
Neither of those give anything to vga display. Maybe more on those on a different topic, when I have
time for them.

ibm.jpg
ibm2.jpg
 
a.jpg
b.jpg
c.jpg
d.jpg
e.jpg
f.jpg

A snapshot of a few games I had chance to try out last night.
Paratroopers would not run, it insisted on a color monitor.

Packman would work, but gave strange artefacts on the screen.
Also, I could probably adjust horizontal size from the back of the display.

Heh, must be the slowest packman I have ever tried out :)
 
the IBM monochrome display adapter (MDA) did not support graphics, but there was a popular monochrome graphics card from Hercules (HGC) that was widely cloned. Normally a Hercules graphics card would replace the MDA card and support both text and graphics. I've never heard of trying to use both an MDA and HGC in the same computer at the same time. Hercules also, iirc, made a color graphics card that could be used alongside an MDA card but that was of course intended for a color monitor. I recommend that you double-check whether the graphics card is actually a color graphics card, if so you should avoid connecting your monochrome monitor to it since it expects a slightly different timing and you risk causing damage to it.

It is definitely not normal to expect to move a monitor back and forth between two cards. It wasn't the most common thing to see, but you could connect both a monochrome and a color monitor to a PC or XT (or even an AT), each monitor connected to its own card. I am guessing that the second card was intended to be used this way.
 
No, HGC and MDA will most assuredly not coexist in the same system. Both use the same I/O port addresses and memory address range. Of course, CGA and MDA/HGC can work together, but that's well-documented.
 
This is why I'm pretty sure that the second card is actually a CGA card, which is in turn why I recommend not connecting a 5151 monitor to it.
 
Thank you for your comments.

Both video adapters came with this unit and they were installed.
But the computer came with one monitor.

If that green monitor is not meant for the graphics card, I will not plug it in there
any longer. It could be, that the artefacts in packman game were due to some compatibility
issue.

Next thing I will attempt is to plug that vga adapter and see if it works with the XT.
 
1.jpg
2.jpg
3.jpg
4.jpg

All right!

Replaced ram chip from U8, from the memory extension card, and immediately got back to 512kb ram !
Since all chips are socketed, that was almost too easy (being used to desolder ram chips from C64's, that often don't have sockets).

Then I decided to try my old trident VGA.
removed the mono card and the Hercules. I took also pics from both of them.
Then, switched dip switches from XT 5160 motherboard 5 = ON, 6 = ON.
Plugged VGA display and immediately got picture on the screen!

Triden vga works... sort of. Many letters are mixed up in weird way. gets very confusing to guess
what the game names are for example, because the text is scrambled. Also, managed to open CAT -game.
It shows strange effect, vertical black lines.

I'm assuming, that trident adapter is not fully compatible or not in the right mode.
The Trident card has a number of dip switches of its own, I must now research what do those mean.
 
That little Hercules is a GB200 Hercules Color Card. It should have that model number on the back side in one corner.
 
I'm assuming, that trident adapter is not fully compatible or not in the right mode.
The Trident card has a number of dip switches of its own, I must now research what do those mean.
Does it work OK on another machine? That looks like a RAM fault on the video card to me.
 
5.jpg
6.jpg
7.jpg
8.jpg
9.jpg

I don't see the type of that Hercules card, but yeah, I do think it is color card.
I found two batch files in the root of C: . One changing to mono and the other changing
to color mode in dos. This computer must have had two display in its past. Perhaps
the dealer sold the color monitor separately, who I bought this computer from.

Someguy: I agree. I found this info for the trident card:
https://stason.org/TULARC/pc/graphics-cards/U-Z/UNIDENTIFIED-XVGA-TRIDENT-TVGA-8-BIT.html

There is not much that can go wrong with the dip switches. Most of them can be ON, and
they were. I tried if sw5 = OFF would change anything - it did not.

I figured, if I could see any changes by unplugging the ram on that card, and changing the order,
but no, it did not result any change. I think this ram is the same, what C64C model (the newer motherboard) has.
I do not have many of those rams available, just a few and I'm not sure, which are good. I could try to find
good deal on ebay for 10 pack of those rams, but I'll try that maybe later. One other choise to test first is
to try out the card with older monitor, not a flat screen, that I have here. I think I have one old monitor
somewhere, that I will try first, before acquiring any new rams for that card.

Especially, because I have a dead Mikromikko computer. It had 16bit VGA card, also trident.
Plugged it in to the XT and it works! And no trouble with the picture at all! It's really great now,
I can try out any games that I have here so far.

What are your suggestions for good games for the XT ?
Tried out cosmic crusader and liked it much ! My better half trying out the Pitstop II here,
playable, but maybe not so much fun in the end. Paratroopers is one classic, that I had.
I must also put sopwith to the computer.

Is there any point in trying to add sound blaster to it ? I guess most applicaple games have no sound card support.
I don't remember if I have 8 bit sound blaster though. I dont have adlib card, never had those.
 
Decided to add 3.5 inch floppy to my IBM XT, even though the original floppy adapter
(and I guess bios and the driver) is only able to handle 720kb dd discs.

Waited for weeks for the 37pin male D connector, but at least it was very cheap
coming from china. Used old floppy cable for it, carefully double checking the
instructions while soldering it ready last night.

And for once, everything worked straight up at first attempt!
What a great add-on to upgrade from 360kb 5.25" floppies to double sized 3.5" ones!
And now the IBM is capable of receiving media from several other pc:s that I have at hand.

edit:

still thinking how to tidy up the setup. Wondering, If I put smaller (1.2mb) floppy
replacing the original and I could then fit the 3.5" floppy also inside the chassis.
I guess, that 1.2mb floppy will work as 360kb DD floppydrive just the same as 3.5" drive does
work in DD mode ?

But then again, I'm not 100% sure, if I want to remove the original monster floppydrive
from the chassis. I'm going to sleep over it :)

1.jpg
2.jpg
3.jpg
4.jpg
 
Decided to add 3.5 inch floppy to my IBM XT, even though the original floppy adapter
(and I guess bios and the driver) is only able to handle 720kb dd discs.
But, if you change the floppy adapter you can run a 1.44 HD drive on the XT:

http://www.vcfed.org/forum/showthread.php?9661-2M-BIOS-extension-for-PC-XTs

I've done it and it works great!

http://www.vcfed.org/forum/showthread.php?57558-Looking-for-a-TSR-file-called-2M




still thinking how to tidy up the setup. Wondering, If I put smaller (1.2mb) floppy
replacing the original and I could then fit the 3.5" floppy also inside the chassis.
I guess, that 1.2mb floppy will work as 360kb DD floppydrive just the same as 3.5" drive does
work in DD mode ?

But then again, I'm not 100% sure, if I want to remove the original monster floppydrive
from the chassis. I'm going to sleep over it :)
That will never work. You need a HD controller to run a 1.2MB drive; the use of 360K disks, notwithstanding.
 
Half height 360K drives are another option to get all the drives located inside the case.

Updating the BIOS and upgrading the disk controller to high density capable is an option but the 1.2MB will still be iffy in terms of writing disks that 360k floppy drives can read. The 1.2MB will be able to read the 360k boot disks it creates so that may not matter match to your use case.
 
Updating the BIOS and upgrading the disk controller to high density capable is an option ...
You will be referring to the motherboard BIOS. Although the two 1986 dated motherboard BIOS revisions contain code for 1.2M drives (see [here]), attempts by me and others to gain 1.2M operation by upgrading the motherboard BIOS to a 1986 dated one, and substituting a BIOS-less HD controller in place of the DD controller, did not work.

Software is also required (in addition to the HD controller). We could not get DRIVER.SYS to work for this. 2M-XBIOS software works. What also works is a HD controller that contains a BIOS expansion ROM that supports 1.2M drives.

Methods of obtaining 1.2M operation on the IBM 5160 are at [here].
 
But, if you change the floppy adapter you can run a 1.44 HD drive on the XT:

http://www.vcfed.org/forum/showthread.php?9661-2M-BIOS-extension-for-PC-XTs

I've done it and it works great!


Thanks to everyone for your comments!

Ok, so, I'm out of luck trying to use 1.2Mb floppy drive with ibm original floppy card.

But it happens, I have this Goldstar Prime 2 I/O card:

5.jpg
6.jpg
7.jpg

So, perhaps I have a chance here? My steps would be to remove the old
floppy adapter and full size 360kb floppy drive. And replace them with Goldstar
card and add both 1.2Mb and 1.44Mb floppy drives to the same cable.

And, I need to load 2M-XBIOS driver (to my dos 3.3) from the hard drive.
In theory, this would do it ? Assuming that untested Goldstar IO card is working unit
in the first place. I do not remember where I got it, it must have been 20+ years in my storage.
 
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