Personal System/2 ... System 36/38
Personal System/2 ... System 36/38
It wasn't until I was reading this message that I realized that the
smaller single user system was referred to as a /Personal/ System as
opposed to just a System which is used by multiple people.
Interesting twist. I'm not at all surprised by that. It's so subtle
IBM that it seems to fit to me.
http://ps-2.kev009.com/pcpartnerinfo/ctstips/9486.htm
Dave, are these the ones you got?
https://ibmmuseum.com/Adapters/5250/IBM/MCA/3638FFF8/
I was Trolling the Great Moravian Hope on 8x 8088s. Not sure if they
could control the bus, nor do I think they could juggle even 16MBs.
Maybe V20s, right?
Didn't notice much for special sauce controllers, other than three IBM
silver caps, one sugar cube, nothing exotic.
On 11/1/2021 19:54, IBMMuseum wrote:
Yeah, can't read the two intel DIPs either.
Dave's photos are usually ok, but I think the camera is doing some
rather heavy post-processing on the photos. High contrast detail -
especially text - often looks unnatural/wonky, and low contrast detail
is smudged, more than it should be. Strange...
And they were likely hurried - I don't think I posted them to Facebook
and then re-downloaded them for my webspace, but who knows. That said,
I'm trying to get a better sort of photo rig here and be more
concerned about having the boards cleaned better.
36/38 metal caps 59X3380, 595949, 5959949
https://ibmmuseum.com/Adapters/5250/IBM/MCA/3638FFF8/3638FFF8_Top.jpg
Lower DIP night be an Intel 8259A
https://ardent-tool.com/communications/5250.html
Upper left chip 8088-2 ?
Later 5250 uses 3 256KB DRAM, I >assume< two are for data, one parity.
Both 36/38 and 5250 use the LSD soaked sugar cube, 7378945
36/38 metal caps 59X3380, 595949, 5959949
What does a workstation emulator have to do? Perhaps keep four sessions alive, sordid out the text display, and what? Trying to figure out the need/purpose of the big three. One is not like the others.
Sure wish we had the 36/38 workstation emulator tech ref.
On 11/1/2021 20:08, Louis Ohland wrote:
I was Trolling the Great Moravian Hope on 8x 8088s. Not sure if they
could control the bus, nor do I think they could juggle even 16MBs.
Maybe V20s, right?
Didn't notice much for special sauce controllers, other than three IBM silver caps, one sugar cube, nothing exotic.
On 11/1/2021 19:54, IBMMuseum wrote:
Yeah, can't read the two intel DIPs either.
Dave's photos are usually ok, but I think the camera is doing some
rather heavy post-processing on the photos. High contrast detail -
especially text - often looks unnatural/wonky, and low contrast detail >>> is smudged, more than it should be. Strange...
And they were likely hurried - I don't think I posted them to Facebook
and then re-downloaded them for my webspace, but who knows. That said,
I'm trying to get a better sort of photo rig here and be more
concerned about having the boards cleaned better.
36/38 metal caps 59X3380, 5959949, 5959949
The two silver capped chips on the right are the same.
ESD? Is that "Entry Systems Division" or the much more mundane "Electro Static Discharge"?
36/38 metal caps 59X3380, 595949, 5959949
Forgot, looks to be a VR near the DB15. Why do we need a voltage
regulator by a Twinax port?
Forgot, looks to be a VR near the DB15. Why do we need a voltage
regulator by a Twinax port?
Yes, all the twin-ax terminals and most of the emulation adapters have a voltage regulator there - there is a requirement to terminate a twin-ax chain.
Forgot, looks to be a VR near the DB15. Why do we need a voltage
regulator by a Twinax port?
Yes, all the twin-ax terminals and most of the emulation adapters have a voltage regulator there - there is a requirement to terminate a twin-ax chain.
IBM incorporated "auto" termination in later twin-ax pigtails and had separate terminator caps that could be used. Maybe an IBM tech that installed the 8-bit emulation adapters could provide insight? Jose, can you see?
IBM incorporated "auto" termination in later twin-ax pigtails and had separate terminator caps that could be used. Maybe an IBM tech that installed the 8-bit emulation adapters could provide insight? Jose, can you see?
On 2.11.2021 18:13, IBMMuseum wrote:
IBM incorporated "auto" termination in later twin-ax pigtails and had
separate terminator caps that could be used. Maybe an IBM tech that
installed the 8-bit emulation adapters could provide insight? Jose,
can you see?
Many of the later twinax terminal cables are indeed auto-terminating.
Both ends of the cable are typically terminated by default (by shunting
the line to the ground/shield via two resistors). These resistors get disconnected (mechanically) when you plug something into the connector...
No additional power source is needed for the line termination. I also
don't think that these later terminals and terminal emulator cards are capable of terminating the line. Not sure though.
If the TO-220 part really is a regulator, it probably supplies power for
the line interface chip 7378945(ESD). Negative voltage supply? What does
the package say? Probulation needed...
The four diodes on the adapter card are probably surge protection.
https://ibmmuseum.com/Adapters/5250/IBM/MCA/3638FFF8/3638FFF8_Top.jpg
Lower DIP night be an Intel 8259A
https://ardent-tool.com/communications/5250.html
Upper left chip 8088-2 ?
Later 5250 uses 3 256KB DRAM, I >assume< two are for data, one parity.
Both 36/38 and 5250 use the LSD soaked sugar cube, 7378945
36/38 metal caps 59X3380, 595949, 5959949
What does a workstation emulator have to do? Perhaps keep four sessions alive, sordid out the text display, and what? Trying to figure out the need/purpose of the big three. One is not like the others.
Sure wish we had the 36/38 workstation emulator tech ref.
On 11/1/2021 20:08, Louis Ohland wrote:
I was Trolling the Great Moravian Hope on 8x 8088s. Not sure if they
could control the bus, nor do I think they could juggle even 16MBs.
Maybe V20s, right?
Didn't notice much for special sauce controllers, other than three IBM
silver caps, one sugar cube, nothing exotic.
On 11/1/2021 19:54, IBMMuseum wrote:
Yeah, can't read the two intel DIPs either.
Dave's photos are usually ok, but I think the camera is doing some
rather heavy post-processing on the photos. High contrast detail -
especially text - often looks unnatural/wonky, and low contrast detail >>>> is smudged, more than it should be. Strange...
And they were likely hurried - I don't think I posted them to
Facebook and then re-downloaded them for my webspace, but who knows.
That said, I'm trying to get a better sort of photo rig here and be
more concerned about having the boards cleaned better.
Dave, what systems that used Twinax actually have technical
documentation which -MIGHT- explain the actual card-level functions?
Anyone know of a well written Twinax paper?
On 11/2/2021 12:13, IBMMuseum wrote:
IBM incorporated "auto" termination in later twin-ax pigtails and had separate terminator caps that could be used. Maybe an IBM tech that installed the 8-bit emulation adapters could provide insight? Jose, can you see?
Here:
https://priorart.ip.com/IPCOM/000099938
This describes it a little bit better and with illustrations.
What they show there is the kind of cable you would normally use with
the later terminals/emulator boards.
On 2.11.2021 21:06, Tomas Slavotinek wrote:
On 2.11.2021 18:13, IBMMuseum wrote:
IBM incorporated "auto" termination in later twin-ax pigtails and had
separate terminator caps that could be used. Maybe an IBM tech that
installed the 8-bit emulation adapters could provide insight? Jose,
can you see?
Many of the later twinax terminal cables are indeed auto-terminating.
Both ends of the cable are typically terminated by default (by
shunting the line to the ground/shield via two resistors). These
resistors get disconnected (mechanically) when you plug something into
the connector...
No additional power source is needed for the line termination. I also
don't think that these later terminals and terminal emulator cards are
capable of terminating the line. Not sure though.
If the TO-220 part really is a regulator, it probably supplies power
for the line interface chip 7378945(ESD). Negative voltage supply?
What does the package say? Probulation needed...
The four diodes on the adapter card are probably surge protection.
The Italian company "Farabi" made an 8-bit adapter that is register-compatible with the IBM adapters - so it is documented somewhere. AST and IDEAssociates were also well-known for their 8-bit and microchannel adapters, many times there was apreference for using them instead of the IBM adapters. Twin-ax is a 1Mbps data link that has documented signaling and frame structure.
https://priorart.ip.com/IPCOM/000058785/Using-the-IBM-System-36-38-Emulation-Adapter-Card-As-a-Time-Source
Here:
https://priorart.ip.com/IPCOM/000099938
This describes it a little bit better and with illustrations.
What they show there is the kind of cable you would normally use with
the later terminals/emulator boards.
| Sysop: | Keyop |
|---|---|
| Location: | Huddersfield, West Yorkshire, UK |
| Users: | 296 |
| Nodes: | 16 (2 / 14) |
| Uptime: | 87:17:44 |
| Calls: | 6,658 |
| Files: | 12,203 |
| Messages: | 5,333,879 |
