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IBM 5161 Expansion Chassis

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dongfeng

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I've just got hold of an IBM 5161 Expansion Chassis from eBay, so naturally have a few questions to ask...

I actually only have the inside components - motherboard, extender/receiver card and cable, but I will build it up in an unused XT case I have, along with an original IBM / Western Digital WD25 20MB hard drive and controller card.

I want to connect this to my all-original dual-floppy 5150 - the plan is to build the "ultimate" IBM 5150, using as many original IBM components as possible :)

What I would like to know is, can I run with two monitors? (IBM 5151 mono and 5153 CGA). If so, do they both run together or one at a time, or how to change the output? I'd like the 5151 to be primary, with the CGA for graphics/games.

Which cards can't I put in the expansion chassis? I have been doing some reading up, and I heard some cards are fussy. (I am guessing memory and primary display adapter). Are there any weird technical limitations (like the XT slot 8?)

If anyone here does have an expansion chassis, any chance of a high-quality photograph (taken using Macro) of the case badge? My XT case is missing the badge anyway, but I'd like to get one made up and have no idea how the badge should look.
 
You can run dual display (CGA and monochrome) on any PC - it is just a matter of having enough slots. The DOS MODE command allows you to switch the output from one to the other. Most well written programs will sense which monitor is active (according to DOS/BIOS) and use that automatically.

I will take a peek in my tech ref and see what the restrictions on cards are and post here later.

Be very careful with that cable - it is big, but it is fragile. a lof of those cables spent their lives up against the back of the machine and wedged against a wall, so they are in bad shape.
 
Slot 8

Slot 8

Are there any weird technical limitations (like the XT slot 8?)
Click to expand...
Slot 8 in the 5161 has the same issues as slot 8 in the 5160, but it won't be a problem because slot 8 in the 5160 is where the Extender card goes, and slot 8 in the 5161 is where the Receiver Card goes.
 
mbbrutman said:
You can run dual display (CGA and monochrome) on any PC - it is just a matter of having enough slots. The DOS MODE command allows you to switch the output from one to the other. Most well written programs will sense which monitor is active (according to DOS/BIOS) and use that automatically.
Click to expand...

If you tumble over a program that doesn't sense which monitor being used, you can - as mbbrutman said - use the MODE command, only if the program can be run from DOS. However, if the program is a booter, you have to physically flip some swiches on the motherboard. You might have to pull out the Monocrome monitor cable when using CGA modes by the swiches.
Code: 
Swich Block 1:
5 ON  6 ON  = No Monitor
5 OFF 6 ON  = 40*25 CGA
5 ON  6 OFF = 80*25 CGA
5 OFF 6 OFF = (80*25) MDA or More than one monitor
The swich settings are read into RAM, that's why they can be temporarly altere by software (like the MODE command).
 
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According to the IBM tech ref, if you've got a system with both MDA and CGA you should set the DIP switches for MDA. Otherwise the BIOS won't initialise the MDA and the mono monitor may get damaged.

Whether this would still apply to non-IBM cards and/or monitors, I don't know.
 
JohnElliott said:
According to the IBM tech ref, if you've got a system with both MDA and CGA you should set the DIP switches for MDA. Otherwise the BIOS won't initialise the MDA and the mono monitor may get damaged.

Whether this would still apply to non-IBM cards and/or monitors, I don't know.
Click to expand...

As of I know, VGA monitor initalize by their own BIOS extension, and don't use the swiches at all, but as for EGA/Hercules, Idk, but I think they initalize in the same mode as MDA.
 
per said:
As of I know, VGA monitor initalize by their own BIOS extension, and don't use the swiches at all, but as for EGA/Hercules, Idk, but I think they initalize in the same mode as MDA.
Click to expand...

I was thinking more of non-IBM MDAs and non-IBM MDA monitors, which may not have all the weirdnesses and/or vulnerabilities of genuine IBM hardware. They may not need to be explicitly put into high-resolution mode, for example.
 
Thanks for all the replies, very helpful!

So it appears, when using a 5150, I need to put BOTH display adapters, RAM expansion, sender card and floppy controller in the 5150 itself (and then it's full), and anything else in the expansion unit.

MODE command in DOS looks interesting. I'll read up on it more :)
 
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