29 Jul
2007
29 Jul
'07
9:25 p.m.
I've got an IBM PS/2 Model 25 that I want to put into use as an
infrequently-used terminal using its serial port. I have a few
questions and was wondering if someone could give me a hand:
- Is there IBM PS/2 Model 25 tech and/or repair specs online somewhere?
I figured out how to open the back up, but that just gets at the ISA
slots. I need to get at the floppy drive; I want to know what some of
the 40-pin male connectors are; etc. Which leads me to my next question:
- The floppy drive is toast. Can I replace it with any regular 3.5" HD
drive, or is it unconventional in some way?
- The embedded monitor is ailing (it's dim, and white has a bluish tint
leading me to believe that the red and green guns are giving out). Is
there any way to fix that without jumping through hoops, or is it (no
pun intended) terminal?
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
29 Jul
29 Jul
9:34 p.m.
Jim Leonard wrote:
I've got an IBM PS/2 Model 25 that I want to put
into use as an
infrequently-used terminal using its serial port. I have a few
questions and was wondering if someone could give me a hand:
- Is there IBM PS/2 Model 25 tech and/or repair specs online somewhere?
I figured out how to open the back up, but that just gets at the ISA
slots. I need to get at the floppy drive; I want to know what some of
the 40-pin male connectors are; etc. Which leads me to my next question:
These are around. Give a look for an archive of Louis Ohland's pages.
He might have some info. If he doesn't, let me know and I'll see what I
can dig up.
- The floppy drive is toast. Can I replace it with
any regular 3.5" HD
drive, or is it unconventional in some way?
If memory serves, it takes power over its ribbon.
- The embedded monitor is ailing (it's dim, and
white has a bluish tint
leading me to believe that the red and green guns are giving out). Is
there any way to fix that without jumping through hoops, or is it (no
pun intended) terminal?
You have to jump through some hoops. It might be worth it just to see
if you can adjust it so it'll work well enough for a little while.
Or just get another one. They're around.
Peace... Sridhar
9:56 p.m.
On 29 Jul 2007 at 23:25, Jim Leonard wrote:
I've got an IBM PS/2 Model 25 that I want to put
into use as an
infrequently-used terminal using its serial port. I have a few
questions and was wondering if someone could give me a hand:
Well, there's the IBM .BOO stuff:
http://ps-2.kev009.com:8081/ohlandl/books/ps-2_books.html
and a bit more here:
http://www.walshcomptech.com/selectpccbbs/
Cheers,
Chuck
30 Jul
30 Jul
2:54 p.m.
- The floppy drive is toast. Can I replace it with
any regular 3.5" HD
drive, or is it unconventional in some way?
Some PS/2s used a spaecial floppy drive with, IIRC, a 40 pin card edge
connecotr which carried both the logic signals and power. The signals
were fairly conventional, though, and I might be able to dig out a pinout
of the connnector if you need it.
-tony
31 Jul
31 Jul
8:25 a.m.
On Monday 30 July 2007 17:54, Tony Duell wrote:
I might even have one or more of these drives in my box of floppy drives, if
someone needs one...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
- The floppy
drive is toast. Can I replace it with any regular 3.5" HD
drive, or is it unconventional in some way?
Some PS/2s used a spaecial floppy drive with, IIRC, a 40 pin card edge
connecotr which carried both the logic signals and power. The signals
were fairly conventional, though, and I might be able to dig out a pinout
of the connnector if you need it.
10:24 a.m.
Tony Duell wrote:
I've bootstrapped the machine using the previous DOS 3.3 on the hard
drive, MODE.COM, and a serial cable so that I can get software on/off
the hard drive, but not having a functional floppy drive makes me
nervous. But there's no rush (it's functional enough) so whenever you
get around to it is fine. And thanks!
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
- The floppy
drive is toast. Can I replace it with any regular 3.5" HD
drive, or is it unconventional in some way?
Some PS/2s used a spaecial floppy drive with, IIRC, a 40 pin card edge
connecotr which carried both the logic signals and power. The signals
were fairly conventional, though, and I might be able to dig out a pinout
of the connnector if you need it.
1:01 p.m.
Some PS/2s
used a spaecial floppy drive with, IIRC, a 40 pin card edge
connecotr which carried both the logic signals and power. The signals
were fairly conventional, though, and I might be able to dig out a pinout
of the connnector if you need it.
I've bootstrapped the machine using the previous DOS 3.3 on the hard
drive, MODE.COM, and a serial cable so that I can get software on/off
the hard drive, but not having a functional floppy drive makes me
nervous. But there's no rush (it's functional enough) so whenever you
get around to it is fine. And thanks! 
6:35 p.m.
> Form the PS/2 Hardware Interface TechRef...
> 40 : +12V DC
On Tue, 31 Jul 2007, Chuck Guzis wrote:
That's really odd. By the time the PS/2 was
around, every 3.5" drive
that I can think of in current production at the time used +5 only.
But sometimes cabled to a DC37 for an _IBM_ external 5.25"
9:29 p.m.
On 31 Jul 2007 at 18:35, Fred Cisin wrote:
But sometimes cabled to a DC37 for an _IBM_ external
5.25"
On a model 25? I didn't think one could cable up an external 5.25"
drive to the primary diskette controller on it. Didn't this require
the type 2 (enhanced) adapter? In the MCA models, the external 5.25"
drives had its own PSU and controller (Diskette Adapter/A).
In any case, this might be helpful to some:
http://www.tavi.co.uk/ps2pages/fdadapt.html
http://www.mcamafia.de/pdf/ibm_hitrc06.pdf
Cheers,
Chuck
7:33 p.m.
Chuck Guzis wrote:
On 31 Jul 2007 at 21:01, Tony Duell wrote:
Just because it's on the connector doesn't mean it was used. 8-)
Peace... Sridhar
Form the PS/2 Hardware Interface TechRef...
40 : +12V DC
That's really odd. By the time the PS/2 was around, every 3.5" drive
that I can think of in current production at the time used +5 only.
1 Aug
1 Aug
3:22 p.m.
On 31 Jul 2007 at 21:01, Tony Duell wrote:
I've not actually verified that voltage is present (I don't own any PS/2
stuff), nor have I checked it's sued on the floppy drive (I do have one
of the drives somewhere, I think).
I was given the Hardware Interface Techref by a friend who had no further
use for it, and who knows I collect techncial manauls. As is well-knwon,
this manual doesn't contain schematics, or ROM source listings, or
anything that makes the old IBM PC family TechRefs really interesting,
but of course I thanked said friend for the manual and added to the shelf.
The pinout I typed in last night was from a section on the floppy
drive/controller subsystem. It's not Model 25 (or any other Model)
specific. It's quite possible some machines don't provide +12V there, if
none of the supported options for that connector would have needed it.
-tony
Form the PS/2 Hardware Interface TechRef...
40 : +12V DC
That's really odd. By the time the PS/2 was around, every 3.5" drive
that I can think of in current production at the time used +5 only.
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ard＠p850ug1.demon.co.uk -
cclist＠sydex.com -
cisin＠xenosoft.com -
ploopster＠gmail.com -
rtellason＠verizon.net -
trixter＠oldskool.org