25 Oct
2001
25 Oct
'01
3:19 a.m.
Hello all,
There was more demand for some of these than I would have guessed....
Thanks, however, to Sellam's Apple II Random Number Generator (heh --
couldn't resist), the "winners" have been chosen.
Unfortunately, I left the list at home, so I'll notify people later today,
when I go home for lunch.
Still no takers on the Async cards (Tony is correct about the two jumper
blocks), and still plenty of floppy controllers.
Also, Tony was spot on about the Everex card. The 6116 is in a socket that
can also accommodate a larger chip. I'd go with his guess that this is some
sort of QIC controller/formatter... It's still up for grabs....
Rich B.
"They that can give up essential liberty
to obtain a little temporary safety deserve
neither liberty nor safety." -- Ben Franklin
25 Oct
25 Oct
11:18 a.m.
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12:34 p.m.
You mean that nobody wants a current-loop capable
card? Zog!. The other
feature of these cards (if it's the IBM card I think it is) is that it's
one of the few cards that will work in slot 8 of a real IBM PC/XT. It can
assert the right signal to enable the bus buffers on the motherboard.
Actually after some point just about everything started being designed
to be slot-8 compatible. I've got slot-8 compatible VGA cards....
Eric
12:57 p.m.
...stands to reason, since to PC had no 16-bit slots.
Dick
----- Original Message -----
From: "Eric J. Korpela" <korpela(a)ssl.berkeley.edu>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, October 25, 2001 3:34 PM
Subject: Re: ISA cards for free..
You mean that
nobody wants a current-loop capable card? Zog!. The other
feature of these cards (if it's the IBM card I think it is) is that it's
one of the few cards that will work in slot 8 of a real IBM PC/XT. It can
assert the right signal to enable the bus buffers on the motherboard.
Actually after some point just about everything started being designed
to be slot-8 compatible. I've got slot-8 compatible VGA cards....
Eric
2:03 p.m.
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2:56 p.m.
The IBM Async card has logic to do this (you have to
jumper the 2 pin
header in the middle of the card). Some M$ bus mouse cards have a similar
feature. Those are all I've seen, but Eric has reported seeing 8 bit VGA
cards that can do this. Maybe others as well.
I've got an Everex 1200 bps modem, a Video Seven VEGA VGA, and a no-name
NE1000 compatibile ethernet card that claim slot 8 compatibility in their
docs. Most other 8 bit cards I have have no docs.
Eric
2:11 p.m.
New subject: SLOT 8 (was: ISA cards for free..
"SLOT 8" compatible IS NOT ABOUT 8 bit v 16 bit!
"SLOT 8" compatible is whether it will work in an IBM XT (not
compatibles) in slot #8 (the slot closest to the power supply).
In the REAL IBM XT (not necessarily compatibles), that slot is different
from the other 7.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
<A HREF= "http://www.xenosoft.com/dogears" >DogEars</A>
On Thu, 25 Oct 2001, Richard Erlacher wrote:
...stands to reason, since to PC had no 16-bit slots.
Dick
----- Original Message -----
From: "Eric J. Korpela" <korpela(a)ssl.berkeley.edu>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, October 25, 2001 3:34 PM
Subject: Re: ISA cards for free..
> > You mean that nobody wants a current-loop capable card? Zog!. The other
> > feature of these cards (if it's the IBM card I think it is) is that
it's
> > one of the few cards that will work in slot 8 of a real IBM PC/XT. It can
> > assert the right signal to enable the bus buffers on the motherboard.
>
> Actually after some point just about everything started being designed
> to be slot-8 compatible. I've got slot-8 compatible VGA cards....
>
> Eric
2:47 p.m.
New subject: SLOT 8 (was: ISA cards for free..
At 04:11 PM 10/25/2001 -0700, you wrote:
"SLOT 8" compatible IS NOT ABOUT 8 bit v 16
bit!
"SLOT 8" compatible is whether it will work in an IBM XT (not
compatibles) in slot #8 (the slot closest to the power supply).
In the REAL IBM XT (not necessarily compatibles), that slot is different
from the other 7.
Was this an issue in the PC, or just the PC/XT?
Gordon
3:25 p.m.
New subject: SLOT 8 (was: ISA cards for free..
At 04:11 PM 10/25/2001 -0700, you wrote:
>"SLOT 8" compatible IS NOT ABOUT 8 bit v 16 bit!
>"SLOT 8" compatible is whether it will work in an IBM XT (not
>compatibles) in slot #8 (the slot closest to the power supply).
>In the REAL IBM XT (not necessarily compatibles), that slot is different
>from the other 7.
On Thu, 25 Oct 2001, Gordon Zaft wrote:
Was this an issue in the PC, or just the
PC/XT?
On the PC (5150) the problem with slot 8 was solved by having 5 slots.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
5 p.m.
New subject: SLOT 8 (was: ISA cards for free..
Not necessarily, right? After all, if the 8-slot motherboard was just the
5-slot with the last 3 slots step-and-repeat-ed ...
Dick
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, October 25, 2001 6:25 PM
Subject: Re: SLOT 8 (was: ISA cards for free..
At 04:11 PM 10/25/2001 -0700, you wrote:
>"SLOT 8" compatible IS NOT ABOUT 8 bit v 16 bit!
>"SLOT 8" compatible is whether it will work in an IBM XT (not
>compatibles) in slot #8 (the slot closest to the power supply).
>In the REAL IBM XT (not necessarily compatibles), that slot is different
>from the other 7.
On Thu, 25 Oct 2001, Gordon Zaft wrote:
Was this an issue in the PC, or just the
PC/XT?
On the PC (5150) the problem with slot 8 was solved by having 5 slots.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
8:26 p.m.
New subject: SLOT 8 (was: ISA cards for free..
At 05:25 PM 10/25/2001 -0700, you wrote:
I'm aware that the PC has only 5 slots, I have one sitting in my
office. What I meant was, is there a corresponding problem with the slot
closest to the power supply in the PC?
Gordon
Gordon Zaft
zaft(a)azstarnet.com
At 04:11 PM
10/25/2001 -0700, you wrote:
>"SLOT 8" compatible IS NOT ABOUT 8 bit v 16 bit!
>"SLOT 8" compatible is whether it will work in an IBM XT (not
>compatibles) in slot #8 (the slot closest to the power supply).
>In the REAL IBM XT (not necessarily compatibles), that slot is different
>from the other 7.
On Thu, 25 Oct 2001, Gordon Zaft wrote:
Was this an issue in the PC, or just the
PC/XT?
On the PC (5150) the problem with slot 8 was solved by having 5 slots.
26 Oct
26 Oct
7:29 a.m.
New subject: SLOT 8 (was: ISA cards for free..
Sorry for the flippancy.
No, the PC doesn't have that problem, and it's not related to the position
relative to the power supply, other than that being a convenient way to
identify it.
I have no idea why IBM did that. Perhaps intending it for some
"special" card that would need it, such as a coprocessor? Maybe Tony
could explain why somebody would design it that way.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
1:39 p.m.
New subject: SLOT 8 (was: ISA cards for free..
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10:30 p.m.
New subject: SLOT 8 (was: ISA cards for free..
From the description I got the other day, it's
slots 1, 2, and 3 that don't
exist in the PC. Isn't slot 8 the one nearest
the power connector?
So ... slot 8 was a layout error, then? ... or was it just stupidity?
Dick
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Friday, October 26, 2001 4:39 PM
Subject: Re: SLOT 8 (was: ISA cards for free..
At 04:11 PM 10/25/2001 -0700, you wrote:
The problem with slot 8 in the PC is that it doesn't exist :-). The PC
only has 5 slots.
More seriously, the IBM PC/XT is the only true-blue IBM PC family machine
to have this 'problem'. All the slots are electrically identical on the
PC. And on the expansion unit. And on the AT and PC/286 (well, there are
some 8-bit only slots and some with the 16 bit extension on both of those
machines, but all the 16 bit slots are the same, and the 8 bit part of
all 8 slots is the same). No problems with one slot being the 'wrong
side' of a buffer.
-tony
"SLOT 8" compatible IS NOT ABOUT 8 bit v
16 bit!
"SLOT 8" compatible is whether it will work in an IBM XT (not
compatibles) in slot #8 (the slot closest to the power supply).
In the REAL IBM XT (not necessarily compatibles), that slot is different
from the other 7.
Was this an issue in the PC, or just the PC/XT?
25 Oct
25 Oct
2:50 p.m.
New subject: SLOT 8 (was: ISA cards for free..
REALLY! I had no idea that they'd so something so silly as dedicate a slot on
an otherwise modern (unlike the APPLE-][) backplane.
What's different about that slot? I've never owned a "real" XT, so
I've never
had to wrestle with that. My first PC was a '186-based clone, and I've never
looked back. Was that "slot-8" compatibility creature a bug in the PC as well?
Dick
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, October 25, 2001 5:11 PM
Subject: SLOT 8 (was: ISA cards for free..
"SLOT 8" compatible IS NOT ABOUT 8 bit v 16
bit!
"SLOT 8" compatible is whether it will work in an IBM XT (not
compatibles) in slot #8 (the slot closest to the power supply).
In the REAL IBM XT (not necessarily compatibles), that slot is different
from the other 7.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
<A HREF= "http://www.xenosoft.com/dogears" >DogEars</A>
On Thu, 25 Oct 2001, Richard Erlacher wrote:
> ...stands to reason, since to PC had no 16-bit slots.
>
> Dick
>
> ----- Original Message -----
> From: "Eric J. Korpela" <korpela(a)ssl.berkeley.edu>
> To: <classiccmp(a)classiccmp.org>
> Sent: Thursday, October 25, 2001 3:34 PM
> Subject: Re: ISA cards for free..
>
>
> > > You mean that nobody wants a current-loop capable card? Zog!. The other
> > > feature of these cards (if it's the IBM card I think it is) is that
it's
> > > one of the few cards that will work in slot 8 of a real IBM PC/XT. It
can
> >
assert the right signal to enable the bus buffers on the motherboard.
>
> Actually after some point just about everything started being designed
> to be slot-8 compatible. I've got slot-8 compatible VGA cards....
>
> Eric
3:24 p.m.
New subject: SLOT 8 (was: ISA cards for free..
On Thu, 25 Oct 2001, Richard Erlacher wrote:
REALLY! I had no idea that they'd so something so
silly as dedicate a slot on
an otherwise modern (unlike the APPLE-][) backplane.
A company as big as IBM "doesn't HAVE TO learn from the mistakes of
others". Remember the PCJr original keyboard?
What's different about that slot?
"Wrong" side of a buffer.
I've never owned a "real" XT, so
I've never
had to wrestle with that. My first PC was a '186-based clone, and I've never
looked back. Was that "slot-8" compatibility creature a bug in the PC as well?
IBM had a LOT of serial cards that nobody wanted (on a 5 slot PC, the
market wanted multifunction!)
Every XT from IBM came with a "FREE" serial card. It blocked slot 8 from
being used by anything else that MIGHT have a problem with it, and gave
the public image impression of a generous (they were more expensive then!)
freebie.
Was that "slot-8" compatibility creature a
bug in the PC as well?
Yes and no. :-)
Since the PC had 5 slots, there was HARDLY EVER a problem with slot number
8!
--
Grumpy Ol' Fred cisin(a)xenosoft.com
<A HREF= "http://www.xenosoft.com/dogears" >DogEars</A>
4:58 p.m.
New subject: SLOT 8 (was: ISA cards for free..
Yes, but were there any unbuffered slots on the orignal PC?
Dick
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Thursday, October 25, 2001 6:24 PM
Subject: Re: SLOT 8 (was: ISA cards for free..
never
On Thu, 25 Oct 2001, Richard Erlacher wrote:
> REALLY! I had no idea that they'd so something so silly as dedicate a slot
on
an otherwise
modern (unlike the APPLE-][) backplane.
A company as big as IBM "doesn't HAVE TO learn from the mistakes of
others". Remember the PCJr original keyboard?
What's different about that slot?
"Wrong" side of a buffer.
> I've never owned a "real" XT, so I've never
> had to wrestle with that. My first PC was a '186-based clone, and I've
> looked back. Was that "slot-8"
compatibility creature a bug in the PC as
well?
IBM had a LOT of serial cards that nobody wanted (on a 5 slot PC, the
market wanted multifunction!)
Every XT from IBM came with a "FREE" serial card. It blocked slot 8 from
being used by anything else that MIGHT have a problem with it, and gave
the public image impression of a generous (they were more expensive then!)
freebie.
Was that "slot-8" compatibility
creature a bug in the PC as well?
Yes and no. :-)
Since the PC had 5 slots, there was HARDLY EVER a problem with slot number
8!
--
Grumpy Ol' Fred cisin(a)xenosoft.com
<A HREF= "http://www.xenosoft.com/dogears" >DogEars</A>
26 Oct
26 Oct
1:45 p.m.
New subject: SLOT 8 (was: ISA cards for free..
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10:36 p.m.
New subject: SLOT 8 (was: ISA cards for free..
Actually, if one counts up the loads ... it does require an extra buffer to
handle 8 slots, so it seems they've split the bus between two buffers. Of
course they're in series, which makes them skewed somewhat, but at 5 MHz ... who
cares? Apparently they're counting to a pretty conservative standard, however.
Dick
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Friday, October 26, 2001 4:45 PM
Subject: Re: SLOT 8 (was: ISA cards for free..
From a quick glance at the schematics, there's the CPU data bus which is
buffered by a '245. The far side of that goes to the first 7 slots, and
to memory on the motherboard, etc. And to one side of another '245. The
other side of that goes to the data lines on the motherboard I/O chips,
the BIOS ROMs, and to the data lines on slot 8. The card in slot 8 has to
pull a line low during reads to enable this last buffer.
No idea why they did this, if indeed there is a good reason.
> > I've never owned a "real" XT, so I've never
> > had to wrestle with that. My first PC was a '186-based clone, and I've
never
What's different about that slot?
"Wrong" side of a buffer. > > looked back. Was that "slot-8"
compatibility creature a bug in the PC as
well?
IBM had a LOT of serial cards that nobody wanted (on a 5 slot PC, the
Although the IBM Async card does have the current loop feature which most
clones missed off. Of course I'm about the only person to want something
like that :-)
market wanted multifunction!)
Every XT from IBM came with a "FREE" serial card. It blocked slot 8 from
being used by anything else that MIGHT have a problem with it, and gave
the public image impression of a generous (they were more expensive then!)
freebie.
IBM screwed up a bit on the design of the portablePC. This uses a normal
XT motherboard (with the slot 8 problem). But the positioning of the disk
drives means that an Async card will just not fit in slot 8 (it's
litterally about 1/4" too small a space). So slot 8 is essentially
wasted. IMHO that machine should have been a little deeper from front to
back (nobody would have noticed) so that the async card would fit in slot 8.
-tony
8282
days inactive
8284
days old
18 comments
6 participants
participants (6)
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ard＠p850ug1.demon.co.uk -
cisin＠xenosoft.com -
edick＠idcomm.com -
korpela＠ssl.berkeley.edu -
r_beaudry＠hotmail.com -
zaft＠azstarnet.com