Subject: RE: IBM 5161

From: Bill Allen Jr <[email-masked]>
Date: Tue Apr 1 23:16:00 2003

The ibm 5161 expansion box was designed for use with
the ibm pc.

the pc had fewer slots then the later released pc xt
and it's power supply was too small to handle a hard
drive.

the exp box added a hard drive to the system and
provided extra card slots ( i think the box also had
additional bios or came with an extra fixed disk rom
chip that went into the pc).

the card that connects to the ribbon cables that come
from the exp box goes into one of the pc's card slots.

i cannot remember if it is slot specific or if it can
go into any slot - there is a plate on the pc's back
that removes to allow the ribbon cables to exit the
case.

a local retired ibm ce had asked me years ago if i had
ever seen one - as he was looking for one at the time.

i was told that the expansion box was a little rare
because, shortly after the pc was released that pc xt
was released .

the pc xt has a large enough power supply to support
a hard drive as well as the bios to operate one and it
has eight card slots.

Bill  

Message: 44
From: "Witchy" <[email-masked]>
To: <[email-masked]>
Subject: IBM 5161
Date: Mon, 31 Mar 2003 20:25:09 +0100
Reply-To: [email-masked]

Hi collecting folks,

A surprise consignment arrived for me this morning -
an IBM 5150 in not 
bad
condition complete with keyboard/monitor and a 5161
expansion box, 
spare
expansion card and 2 extender cables.....reading the
classiccmp 
archives
back to 1998 makes me think I should be impressed
since the 5161 isn't 
that
common? It all apparently works but I won't be able to
set it up fully 
till
tomorrow. Not much info about it on the web either,
though because 5161 
is
obviously bits of a phone number there's a very high
signal to noise
ratio.....

cheers

--
adrian/witchy
www.binarydinosaurs.co.uk - the online computer museum
www.snakebiteandblack.co.uk - monthly gothic
shenanigans

--__--__--

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Wed Apr 2 13:09:01 2003

> chip that went into the pc).
NOT for the hard disk.
> that removes to allow the ribbon cables to exit the

The slots on the PC are wired in parallel.  There is NO electrical
difference between them, other than physical distances.
But in the XT, one slot is different.  At the time of the release of the
XT, IBM was worried that people would use that slot for something
incompatible, and they had a giant surplus of serial (RS232 and current
loop) cards that nobody wanted, so they provided a "FREE" serial card to
block off that slot.

> a hard drive as well as the bios to operate one and it

The XT BIOS does NOT include hard drive support.  The ROM that includes
that extension to the BIOS is on the XT hard drive controller card.  The
AT was the first to include hard drive support in the motherboard BIOS.
All but the very earliest 5150s had a BIOS that would scan for additional
ROMs, and other than number of slots and power supply inadequacy, would
take a hard drive EXACTLY the same way as an XT.

I think that the 5161 CAN be used on an XT, if eight is not enough.

BTW, IBM called it a "FIXED DRIVE", instead of calling it a "HARD
DRIVE".  At their "Technical Briefing" when they introduced it, 
they said that that was "because "HARD DRIVE" might sound like 
it was "hard to use", and therefore "FIXED DRIVE" would have better
connotations".  Some wise-ass in the audience said, "... in a VETERINARY
context?"
They also called the motherboard a "SYSTEM BOARD", due to possible
associations of "MOTHERBOARD" with the usage of the word "MOTHER..." 
by the Black Panthers, et al.

--
Grumpy Ol' Fred        [email-masked]

---

From: [email-masked] (Tony Duell)
Date: Wed Apr 2 18:07:24 2003

> > chip that went into the pc).

AFIAK there is no extra BIOS ROM for the expansion box.

> > that removes to allow the ribbon cables to exit the

The Extender crd that goes into the PC has a DC62 connector on the 
bracket. There's a similar one on the Receiver card in the expansion 
unit. You link them with a (round) cable. There are no ribbon cables 
involved, nothing comes out through slots in the PC case.

> difference between them, other than physical distances.

Correct.

> loop) cards that nobody wanted, so they provided a "FREE" serial card to

Why did 'mobody' want them? A serial port is a very useful thing to have...

> block off that slot.

One of the most stupid things IBM ever did was in the 5155 PortablePC. 
That machine has a standard PC/XT motherboard in it. Alas the case is 
just too short (about 1/2" too short) to allow the Async serial card to 
fit in the special slot 8. Which means that slot 8 is essentially useless 
in that machine.

> I think that the 5161 CAN be used on an XT, if eight is not enough.

Correct, it can. It also works on the 5155 'PortablePC', and is the only 
offical way to put a hard disk on that machine. I guess it was a kind of 
early 'docking station' :-)

AFAIK it _doesn't_ work on the 5170 PC/At, even if you only want to put 8 
bit cards in the expansion unit. Pity....

-tony

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Wed Apr 2 18:45:00 2003

> Why did 'mobody' want them? A serial port is a very useful thing to have...

Because they occupied an entire slot (out of 5 on the PC), and other
companies sold "multifunction" cards that could use the same slot for
serial, parallel, clock, and memory.  Most of those were marketed as SIX
functions - how many people remember what the other two functions were? 

However, the IBM "Async" card could ALSO do current loop, which most of
the after market cards could NOT.

> One of the most stupid things IBM ever did was in the 5155 PortablePC. 

It has my nomination for the silliest design.  (particularly when compared
with the comparable Compaq machine which has all slots usable)

---

From: Kevin Handy <[email-masked]>
Date: Wed Apr 2 19:08:01 2003

>functions - how many people remember what the other two functions were? 
floppy, game port

---

From: "Fred Cisin (XenoSoft)" <[email-masked]>
Date: Wed Apr 2 19:27:00 2003

> floppy, game port

floppy was quite rare on multifunction cards (until quite a bit later)
game port was fairly common.

But on a lot of "multifunction" cards (such as AST, Quadram, etc.),
options 5 and 6 were:
print spooling software, and ramdisk software!

---

From: Joe <[email-masked]>
Date: Wed Apr 2 19:47:00 2003

>functions - how many people remember what the other two functions were? 

   Ramdisk and print buffer.

    Joe

---

From: Joe <[email-masked]>
Date: Wed Apr 2 19:48:45 2003

>>functions - how many people remember what the other two functions were? 

    BEEP! Nope.

   Joe

---

From: Mail List <[email-masked]>
Date: Wed Apr 2 21:12:00 2003

> how many people remember what the other two functions were?

Game ( Joystick ) Port ?

In seeing if I could remember what they were, I came across a web site

called ... "die Jumper Site - The Jumper Site"

with jumper settings on A LOT of vintage hardware. In fact, it looks like
scans of the MicroHouse Technical Reference Library, so it might not last.

Samples of just the 8 bit ISA I/O cards

Text format at ... http://www.totalhardware.de/i/iio8_t.htm

Pictures format at ... http://www.totalhardware.de/i/iio8_i.htm

Pictures and Text format at ... http://www.totalhardware.de/i/iio8_1.htm

Main Page at ...

http://www.totalhardware.de/

Best Regards

---

From: [email-masked] (Tony Duell)
Date: Thu Apr 3 15:06:28 2003

> functions - how many people remember what the other two functions were? 

Originally, I think the extra 2 functions were _software_, not hardware 
on the board. Something like a print spooler and RAM disks to use all 
that memory.

Later on, multifunction cards often included a games port, floppy 
controller, and sometimes even video (there was a very popular card in 
the UK that contained 2 serial ports, parallel port, joystick port, 
Hercules/CGA graphics, floppy controller and real time clock -- yes, on 
one full-length board).

> the after market cards could NOT.

That's one reason that I grab them if I see them...

-tony

---

From: "Witchy" <[email-masked]>
Date: Fri Apr 4 12:19:01 2003

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]]On
> Behalf Of Bill Allen Jr
> Sent: 02 April 2003 06:14
> To: [email-masked]
> Subject: RE: IBM 5161
>
>

And presumably *only* the PC, ie not the XT.

> and it's power supply was too small to handle a hard

Yep, 5 slots and a 63W PSU that couldn't even handle a fully populated
backplane if some of the cards were a little power-hungry.

> chip that went into the pc).

Not that I've found, just an 8-slot backplane which immediately loses a slot
because one of them must be occupied by the receiving end of the expander
interface that has to go in the 5150. There might be a BIOS in that
interface though, I didn't really check that. The 5161 has a hard drive
controller card in it as well as a Seagate monster that's probably only 5 or
10 meg.

> from the exp box goes into one of the pc's card slots.

No ribbon cables, just an interface cable that's thicker than my thumb!

> that removes to allow the ribbon cables to exit the

There's a plate on the back, yes, maybe very early boxes used ribbons and
the thicker cables came along later?

> because, shortly after the pc was released that pc xt

Well, a year later anyway, after the 5150 had shifted 200,000 units
according to most websites.

I've put a breakdown of the kit on my IBM page - go to
www.binarydinosaurs.co.uk and click on the link in the very top 'updates'
message.

cheers

--
adrian/witchy
www.binarydinosaurs.co.uk - the online computer museum
www.snakebiteandblack.co.uk - monthly gothic shenanigans

---

From: [email-masked] (Tony Duell)
Date: Fri Apr 4 18:37:00 2003

> And presumably *only* the PC, ie not the XT.

It is documented as working (by IBM) on the XT and PortablePC...

> Not that I've found, just an 8-slot backplane which immediately loses a slot

Yes, that's what I'd expect. It's almost a totally passive backplane, but 
there's a clock generator chip + crystal to generate the 14MHz 'osc' 
signal (which is not taken from the main PC)_

> interface though, I didn't really check that. The 5161 has a hard drive

There isn't...

> controller card in it as well as a Seagate monster that's probably only 5 or

Yep...

> No ribbon cables, just an interface cable that's thicker than my thumb!

That's what all my expansion units have too...

-tony