This puppy arrived a few weeks ago (thankfully in one piece):
https://www.ardent-tool.com/PS55/5560/Dirty_Front.jpg
https://www.ardent-tool.com/PS55/5560/Dirty_Badge.jpg
https://www.ardent-tool.com/PS55/5560/Dirty_Intake.jpg

Yeah it looked rather disgusting, but luckily the plastics weren't
actually yellowed, just really dirty, with a layer of what I presume was
cigarette tar covering everything.

For those unaware, the PS/55 Model 5560 is basically an improved version
of the PS/2 Model 90. The machine has two extra MCA slots in place of
the memory risers:
https://www.ardent-tool.com/PS55/5560/Dirty_Back.jpg

The SIMM sockets were relocated to the planar (under the PSU). The PSU
can be swung out, for easy access to the memory, similar to Models 85/95:
https://www.ardent-tool.com/PS55/5560/Planar_PSU_Out.jpg

But unlike the 85/95, the machine can be operated with the PSU swung
out, making memory related experiments significantly less annoying (even
compared to Model 90).

To my surprise the machine cleaned up rather nicely... after many hours
of scrubbing and some alcohol/q-tip treatment: :)
https://www.ardent-tool.com/PS55/5560/Front_01.jpg
https://www.ardent-tool.com/PS55/5560/Front_02.jpg
https://www.ardent-tool.com/PS55/5560/Back.jpg

The planar and adapter cards needed more than just cleaning as they were
littered with leaking SMD caps. I've removed all of them and cleaned up
the areas that got hit by the leaked electrolyte...
https://www.ardent-tool.com/PS55/5560/Planar_Recap.jpg

....and then reinstalled a few caps here 'n there and decided to test the
board. Unfortunately the original PSU was (and still is) unstable, so I
had to hack together something using a standard ATX PSU. This is totally
safe, I promise!
https://www.ardent-tool.com/PS55/5560/Planar_ATX_Test_01.jpg
https://www.ardent-tool.com/PS55/5560/Planar_ATX_Test_02.jpg

Yay, It works!
https://www.ardent-tool.com/PS55/5560/Screen_01.jpg
https://www.ardent-tool.com/PS55/5560/Screen_02.jpg
https://www.ardent-tool.com/PS55/5560/Screen_03.jpg

Some of the SIMM positions are unreliable and I've since narrowed that
problem down to the process complex board. The planar itself is ok (and
fully recapped now).

Aside from the major design changes mentioned above, there are also many
smaller tweaks everywhere. For example, the system has a provision for a
95-ask Operator Panel:
https://www.ardent-tool.com/PS55/5560/Planar_Front_IO.jpg
https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Stripped.jpg
https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Populated.jpg
https://www.ardent-tool.com/PS55/5560/Panel_Cover_Removed.jpg

Nope, that front panel cover is not removable on a regular Model 90.

The volume pot comes standard with most machines from the PS/55 line. (I
wonder why this was a thing in Japan. These were business machines, and
business software is usually silent... hmm.)

Among the "quality of life" improvements are also these brackets (or
handles?) on the back side of the system. They make opening the unit
much easier:
https://www.ardent-tool.com/PS55/5560/Cover_Slide_Bracket.jpg

Even something as trivial as the MCA slot covers was modified for easier
removal/installation:
https://www.ardent-tool.com/PS55/Pics/Photos/MCA_Slot_Covers.jpg

But there are also some oddities... Like the case lock - it was
relocated to the top cover:
https://www.ardent-tool.com/PS55/5560/Cover_Lock.jpg

And then there's this strange shortened slot cover:
https://www.ardent-tool.com/PS55/5560/Back_Short_Slot.jpg

There's nothing behind it, no unused headers on the board (aside from
the op panel connector), or anything else. Any ideas?

I've updated the 5560 page with the new information and photos:
https://www.ardent-tool.com/PS55/5560/5560.html

And added a 5560 PSU page here:
https://www.ardent-tool.com/PS55/5560/Power.html

What an interesting machine! It's like a Model 90 from a parallel
universe...

Anyway, the tasks left are the PSU repair/restuffing and diagnostic of
the complex memory issue. And then experiments with the normally
unsupported Type 4 platform.

https://www.ardent-tool.com/PS55/Pics/Photos/MCA_Slot_Covers.jpg

Recovering after a wild animal instinct party...

Tom, remember the 7012 Thick/Thin Ethernet Riser P/N 52G4737, FRU
43G0382 Card 2-8 ?

https://ardent-tool.com/RS6000/7012/7012_common.html

Since we have zero Japanese Announcement Letters, we'll probably never
know. BUT remember the Japanese CAD Station brouchure that Sandy sendt?

https://ardent-tool.com/PS55/Docs/PS55_Model_5560-N.pdf

Little Wanna-Be RS/6000... "I think I can, I think I can..."

Control is not convinced there is a problem...

Tom, I can say with experience that the slot cover blank can and will
cut you open if you let it.

Blood for Micro Channel!

Remember, IBM loved to reduce costs. They loved automated assembly.
Wonder how the PS/55s were assembled. With that tab sticking out, how
were the slot covers fed to the picker? The basic covers we have could
be loaded in magazines, I bet. Think of something like staples? each one
fits into the next one....

Perhaps. Maybe IBM Japan figured hand assembly of the blank covers could
be reduced with more populated adapters? Dunno.

On 10/6/2021 15:06, Tomas Slavotinek wrote:
> Even something as trivial as the MCA slot covers was modified for easier
> removal/installation:
> https://www.ardent-tool.com/PS55/Pics/Photos/MCA_Slot_Covers.jpg

Huh... Replaceable power switch / volume front panel... Unpopulated OP
Panel header.

Suggestive of an earlier OP Panel with a display? Probably designed with
it, then they figured out they could get by without it.

Think of the B: Bay display in the 5494.

https://ardent-tool.com/5494/5494.html#Op_Panel

On 10/6/2021 15:06, Tomas Slavotinek wrote:
> Aside from the major design changes mentioned above, there are also many
> smaller tweaks everywhere. For example, the system has a provision for a
> 95-ask Operator Panel:
> https://www.ardent-tool.com/PS55/5560/Planar_Front_IO.jpg
> https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Stripped.jpg
> https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Populated.jpg
> https://www.ardent-tool.com/PS55/5560/Panel_Cover_Removed.jpg
>
> Nope, that front panel cover is not removable on a regular Model 90.

You said "strange" like it's a bad thing.

https://ardent-tool.com/RAID/RAID_Cheetah.html#Cheetah_Side_Card_Front

Bulkhead bracket for a card with an internal port? SCSI? Multi-port?

On 10/6/2021 15:06, Tomas Slavotinek wrote:
> And then there's this strange shortened slot cover:
> https://www.ardent-tool.com/PS55/5560/Back_Short_Slot.jpg
>
> There's nothing behind it, no unused headers on the board (aside from
> the op panel connector), or anything else. Any ideas?

Yeah that's what came to my mind too, the 2-8 adapter has a full-sized
bracket I think, but both are positioned awkwardly above the I/O area.

Speaking of which, the right most portion of the I/O area is completely
unused on the 5560 planar, so I wonder why didn't they shorten it to
make space for a regular slot cover?

Maybe they though it would be confusing with no actual MCA slot behind
it (and adding another MCA slot would be a problem, since the planar
already kinda has 8 slots - 6x MCA + 2x unpopulated DBA). A regular MCA
cover would be more useful, especially for connector brackets (like the
5.25" floppy connector).

Perhaps they wanted to retain the extra I/O space for later development
- second serial port, on-board video...

Or there really was something like the 2-8 adapter planned for the 5560
originally.

We may never know...

The cover is still useful, ideal for a reset button, SD card slot, etc.

On 7.10.2021 3:24, Louis Ohland wrote:
> https://www.ardent-tool.com/PS55/Pics/Photos/MCA_Slot_Covers.jpg
>
> Recovering after a wild animal instinct party...
>
> Tom, remember the 7012 Thick/Thin Ethernet Riser P/N 52G4737, FRU
> 43G0382 Card 2-8 ?
>
> https://ardent-tool.com/RS6000/7012/7012_common.html
>
> Since we have zero Japanese Announcement Letters, we'll probably never
> know. BUT remember the Japanese CAD Station brouchure that Sandy sendt?
>
>
> https://ardent-tool.com/PS55/Docs/PS55_Model_5560-N.pdf
>
> Little Wanna-Be RS/6000... "I think I can, I think I can..."

There was plenty of blood involved when disassembling/reassembling the
machine, even with all these small improvements :-D.

Were the slot covers really installed by machines in the PS/2 world? I
thought the final assembly was done by humans (adapters, slot covers,
drives, cables...)?

Well, what I know is that these tabs make the covers really easy to
slide out.

On 7.10.2021 3:34, Louis Ohland wrote:
> Control is not convinced there is a problem...
>
> Tom, I can say with experience that the slot cover blank can and will
> cut you open if you let it.
>
> Blood for Micro Channel!
>
> Remember, IBM loved to reduce costs. They loved automated assembly.
> Wonder how the PS/55s were assembled. With that tab sticking out, how
> were the slot covers fed to the picker? The basic covers we have could
> be loaded in magazines, I bet. Think of something like staples? each one
> fits into the next one....
>
> Perhaps. Maybe IBM Japan figured hand assembly of the blank covers could
> be reduced with more populated adapters? Dunno.
>
> On 10/6/2021 15:06, Tomas Slavotinek wrote:
>> Even something as trivial as the MCA slot covers was modified for easier
>> removal/installation:
>> https://www.ardent-tool.com/PS55/Pics/Photos/MCA_Slot_Covers.jpg
>

It sure looks like they designed the machine with a server model in
mind. Extra slots, op panel, there's even place for the 3-pin Remote
Power-ON header.

I'll measure the chassis opening to see if it's the right size for two
HDLX-2416 LED units, but I think it is. The pinout is similar to the
8595 one (but not compatible):

https://ardent-tool.com/PS55/5560/5560.html#J31_Op_Panel_Connector

I'll try to figure out the remaining 4 pins later on.

The smaller opening to the left of the volume pot is also curious:
https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Populated.jpg

I'm not sure if that part is Op Panel related. To me it looks more like
a provision for audio jacks (notice the two screw holes right bellow).

On 7.10.2021 3:46, Louis Ohland wrote:
> Huh... Replaceable power switch / volume front panel... Unpopulated OP
> Panel header.
>
> Suggestive of an earlier OP Panel with a display? Probably designed with
> it, then they figured out they could get by without it.
>
> Think of the B: Bay display in the 5494.
>
> https://ardent-tool.com/5494/5494.html#Op_Panel
>
>
> On 10/6/2021 15:06, Tomas Slavotinek wrote:
>> Aside from the major design changes mentioned above, there are also many
>> smaller tweaks everywhere. For example, the system has a provision for a
>> 95-ask Operator Panel:
>> https://www.ardent-tool.com/PS55/5560/Planar_Front_IO.jpg
>> https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Stripped.jpg
>> https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Populated.jpg
>> https://www.ardent-tool.com/PS55/5560/Panel_Cover_Removed.jpg
>>
>> Nope, that front panel cover is not removable on a regular Model 90.
>

Notice the two small circular holes beneath the odd cut-out? Most likely
mounting holes for the barbed fastener for whatever.

On 10/7/2021 03:24, Tomas Slavotinek wrote:
> The smaller opening to the left of the volume pot is also curious:
> https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Populated.jpg

U57 "DSKBOOT" 64F3110 PAL
https://www.ardent-tool.com/PS55/5560/5560.html

Got to love the Japanese penchant for labeling things.

U72 64F3110, TI CF61533FN
https://ardent-tool.com/9590/9590_Planar.html#90_planar
https://ardent-tool.com/9590/9590_Planar.html#90_planar_early

Yep, IBM Japan FTW!

The PAL seems to be wired to the floppy controller. I'll try to figure
out what exactly is going on there...

The link to the early Model 90 planar reminded me something. YouTube
made me rewatch the old LGR PS/2 Motherlode video and @ 16:17 I've
noticed that his board is cut differently than the one in my early Model
90 (see the area around the fan connector). It also has an additional
PAL device in the "SPARE" position (near the power connector):

https://youtu.be/k2R6bwxQqs8?t=977

(pause the video and use the "," and "." keys to move frame by frame)

Probably even earlier sample...

On 7.10.2021 15:42, Louis Ohland wrote:
>
> U57 "DSKBOOT" 64F3110 PAL
> https://www.ardent-tool.com/PS55/5560/5560.html
>
> Got to love the Japanese penchant for labeling things.
>
> U72 64F3110, TI CF61533FN
> https://ardent-tool.com/9590/9590_Planar.html#90_planar
> https://ardent-tool.com/9590/9590_Planar.html#90_planar_early

My DIMM memories suggest there was a surface mount PLCC down in the
front right. A year or so ago.

On 10/7/2021 09:46, Tomas Slavotinek wrote:
> Yep, IBM Japan FTW!
>
> The PAL seems to be wired to the floppy controller. I'll try to figure
> out what exactly is going on there...
>
> The link to the early Model 90 planar reminded me something. YouTube
> made me rewatch the old LGR PS/2 Motherlode video and @ 16:17 I've
> noticed that his board is cut differently than the one in my early Model
> 90 (see the area around the fan connector). It also has an additional
> PAL device in the "SPARE" position (near the power connector):
>
> https://youtu.be/k2R6bwxQqs8?t=977
>
> (pause the video and use the "," and "." keys to move frame by frame)
>
> Probably even earlier sample...
>
> On 7.10.2021 15:42, Louis Ohland wrote:
>>
>> U57 "DSKBOOT" 64F3110 PAL
>> https://www.ardent-tool.com/PS55/5560/5560.html
>>
>> Got to love the Japanese penchant for labeling things.
>>
>> U72 64F3110, TI CF61533FN
>> https://ardent-tool.com/9590/9590_Planar.html#90_planar
>> https://ardent-tool.com/9590/9590_Planar.html#90_planar_early
>

On Wednesday, 6 October 2021 at 21:06:26 UTC+1, Tomas Slavotinek wrote:
> This puppy arrived a few weeks ago (thankfully in one piece):
> https://www.ardent-tool.com/PS55/5560/Dirty_Front.jpg
> https://www.ardent-tool.com/PS55/5560/Dirty_Badge.jpg
> https://www.ardent-tool.com/PS55/5560/Dirty_Intake.jpg
>
> Yeah it looked rather disgusting, but luckily the plastics weren't
> actually yellowed, just really dirty, with a layer of what I presume was
> cigarette tar covering everything.
>
> For those unaware, the PS/55 Model 5560 is basically an improved version
> of the PS/2 Model 90. The machine has two extra MCA slots in place of
> the memory risers:
> https://www.ardent-tool.com/PS55/5560/Dirty_Back.jpg
>
> The SIMM sockets were relocated to the planar (under the PSU). The PSU
> can be swung out, for easy access to the memory, similar to Models 85/95:
> https://www.ardent-tool.com/PS55/5560/Planar_PSU_Out.jpg
>
> But unlike the 85/95, the machine can be operated with the PSU swung
> out, making memory related experiments significantly less annoying (even
> compared to Model 90).
>
> To my surprise the machine cleaned up rather nicely... after many hours
> of scrubbing and some alcohol/q-tip treatment: :)
> https://www.ardent-tool.com/PS55/5560/Front_01.jpg
> https://www.ardent-tool.com/PS55/5560/Front_02.jpg
> https://www.ardent-tool.com/PS55/5560/Back.jpg
>
> The planar and adapter cards needed more than just cleaning as they were
> littered with leaking SMD caps. I've removed all of them and cleaned up
> the areas that got hit by the leaked electrolyte...
> https://www.ardent-tool.com/PS55/5560/Planar_Recap.jpg
>
> ...and then reinstalled a few caps here 'n there and decided to test the
> board. Unfortunately the original PSU was (and still is) unstable, so I
> had to hack together something using a standard ATX PSU. This is totally
> safe, I promise!
> https://www.ardent-tool.com/PS55/5560/Planar_ATX_Test_01.jpg
> https://www.ardent-tool.com/PS55/5560/Planar_ATX_Test_02.jpg
>
> Yay, It works!
> https://www.ardent-tool.com/PS55/5560/Screen_01.jpg
> https://www.ardent-tool.com/PS55/5560/Screen_02.jpg
> https://www.ardent-tool.com/PS55/5560/Screen_03.jpg
>
> Some of the SIMM positions are unreliable and I've since narrowed that
> problem down to the process complex board. The planar itself is ok (and
> fully recapped now).
>
> Aside from the major design changes mentioned above, there are also many
> smaller tweaks everywhere. For example, the system has a provision for a
> 95-ask Operator Panel:
> https://www.ardent-tool.com/PS55/5560/Planar_Front_IO.jpg
> https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Stripped.jpg
> https://www.ardent-tool.com/PS55/5560/Panel_Chassis_Populated.jpg
> https://www.ardent-tool.com/PS55/5560/Panel_Cover_Removed.jpg
>
> Nope, that front panel cover is not removable on a regular Model 90.
>
> The volume pot comes standard with most machines from the PS/55 line. (I
> wonder why this was a thing in Japan. These were business machines, and
> business software is usually silent... hmm.)
>
> Among the "quality of life" improvements are also these brackets (or
> handles?) on the back side of the system. They make opening the unit
> much easier:
> https://www.ardent-tool.com/PS55/5560/Cover_Slide_Bracket.jpg
>
> Even something as trivial as the MCA slot covers was modified for easier
> removal/installation:
> https://www.ardent-tool.com/PS55/Pics/Photos/MCA_Slot_Covers.jpg
>
> But there are also some oddities... Like the case lock - it was
> relocated to the top cover:
> https://www.ardent-tool.com/PS55/5560/Cover_Lock.jpg
>
> And then there's this strange shortened slot cover:
> https://www.ardent-tool.com/PS55/5560/Back_Short_Slot.jpg
>
> There's nothing behind it, no unused headers on the board (aside from
> the op panel connector), or anything else. Any ideas?
>
> I've updated the 5560 page with the new information and photos:
> https://www.ardent-tool.com/PS55/5560/5560.html
>
> And added a 5560 PSU page here:
> https://www.ardent-tool.com/PS55/5560/Power.html
>
> What an interesting machine! It's like a Model 90 from a parallel
> universe...
>
> Anyway, the tasks left are the PSU repair/restuffing and diagnostic of
> the complex memory issue. And then experiments with the normally
> unsupported Type 4 platform.

Sounds like a major surgical operation. Kudos for the extensive effort.

On 7.10.2021 10:24, Tomas Slavotinek wrote:
> I'll measure the chassis opening to see if it's the right size for two
> HDLX-2416 LED units, but I think it is.

The opening is 60 x 26 mm in size - just about perfect for the dual
HDLX-2416 setup:

https://www.ardent-tool.com/PS55/5560/Panel_LED_Display_Fit.jpg

On 8.10.2021 16:32, WBSTClarke wrote:
> On Wednesday, 6 October 2021 at 21:06:26 UTC+1, Tomas Slavotinek wrote:
>> Anyway, the tasks left are the PSU repair/restuffing and diagnostic of
>> the complex memory issue. And then experiments with the normally
>> unsupported Type 4 platform.
>
> Sounds like a major surgical operation. Kudos for the extensive effort.

Thanks! The cleaning can get really tedious, but from the most part it's
actually fun (at least for me xD) - especially when it comes to the
diagnostic and exploring the system. One can always learn something new
along the way...

I've checked the complex and found some corrosion between a couple of
the card-edge contact pads. You can kinda see it on the scan as well
(below the 487 socket):

https://ardent-tool.com/PS55/Complex/60W1_07G3153_Photo_Back.jpg

Some other pads in that general area were rather crummy looking as well,
even after cleaning, so I had to freshen them a bit with a fiberglass pen.

I've tested the complex again (in the same 8595 box as before) and this
time it was stable, even with all 8 SIMM sockets populated - no memory
errors. Not even after removing/reistalling the complex a few times.

So the last item on the list is the PSU...

So... aside from systems that have an op console function, what can be
expected of attempts to add a LED display?

On 10/10/2021 15:06, Tomas Slavotinek wrote:
> On 7.10.2021 10:24, Tomas Slavotinek wrote:
>> I'll measure the chassis opening to see if it's the right size for two
>> HDLX-2416 LED units, but I think it is.
>
> The opening is 60 x 26 mm in size - just about perfect for the dual
> HDLX-2416 setup:
>
> https://www.ardent-tool.com/PS55/5560/Panel_LED_Display_Fit.jpg
>

Please do. It makes me curious, blue. What is this PAL doing? Is it
memory? Wired to the FDC, that doesn't seem quite sensible.

Does it add function? DSKBOOT seems to suggest something related to
booting, not sure it is O/S related, more like IML? Maybe DSKBOOT
supports DBA-ESDI?

You must.. probe it! Yes!

What pins of the FDC does it connect to? What other components does it
connect to?

How about this for an unsupported rumor... the DSKBOOT connects the FDC
to NVRAM to enable booting from CDROM... ;)

On 10/7/2021 09:46, Tomas Slavotinek wrote:
> The PAL seems to be wired to the floppy controller. I'll try to figure
> out what exactly is going on there...

On 11.10.2021 1:47, Louis Ohland wrote:
> Please do. It makes me curious, blue. What is this PAL doing? Is it
> memory? Wired to the FDC, that doesn't seem quite sensible.

Why not? The PAL is sitting right next to the FDC and at least some of
the traces go towards the controller.

> Does it add function? DSKBOOT seems to suggest something related to
> booting,

Yeah... the name. The "DSK" part makes sense - floppy DiSK, DBA DiSK -
could be either (or both) if we go just by the name itself.

> not sure it is O/S related, more like IML? Maybe DSKBOOT supports DBA-ESDI?

That's the thing, everything related to the OS "BOOT" process is handled
in software/firmware. I can't think of anything boot-related that would
require a special HW logic.

The only IML-related thing that requires a special HW is the
E0000-FFFFFh range ROM/RAM switching, but that's implemented on the
processor complex.

> You must.. probe it! Yes!
>
> What pins of the FDC does it connect to? What other components does it
> connect to?

Yep... Probulation time!

> How about this for an unsupported rumor... the DSKBOOT connects the FDC
> to NVRAM to enable booting from CDROM... ;)

:-D I like the enthusiasm, but that doesn't make much sense. The two
components are already connected to the planar I/O bus. Not because they
need to talk to each other directly, but because the CPU needs to be
able to address both of them.

Going by the little information we have currently, I only have one
theory - the PAL handles the FDC reset initialization. The 82077
controller can be switched between 3 different modes (PC AT, PS/2, and
Model 30). This is done by setting two of the inputs in a certain way
when the RESET line is toggled. I'll have to check the datasheet again,
but I don't think this can be achieved with high value pull-up or
something similar in this particular case. So perhaps "DSKBOOT" means
"DiSK controller BOOT"? Though something like "FDCINIT" would make much
sense in this context...

The 64F3110 PAL can be found on the following planars:

https://ardent-tool.com/9590/9590_Planar.html
https://ardent-tool.com/PS55/5560/5560.html
https://ardent-tool.com/9533/9533.html
https://ardent-tool.com/2011_2121/2121_Planar.html
(the PS/1 stuff is unfinished and not listed on the Ardent Tool index)

And possibly many more, since we don't always track the PALs/GALs and
other glue...

PS/1 hmm, unless it uses the PS/2 FDC mode, my theory is probably wrong.

On 11.10.2021 12:00, Tomas Slavotinek wrote:
> On 11.10.2021 1:47, Louis Ohland wrote:
>> Please do. It makes me curious, blue. What is this PAL doing? Is it
>> memory? Wired to the FDC, that doesn't seem quite sensible.
>
> Why not? The PAL is sitting right next to the FDC and at least some of
> the traces go towards the controller.
>
>> Does it add function? DSKBOOT seems to suggest something related to
>> booting,
>
> Yeah... the name. The "DSK" part makes sense - floppy DiSK, DBA DiSK -
> could be either (or both) if we go just by the name itself.
>
>> not sure it is O/S related, more like IML? Maybe DSKBOOT supports DBA-ESDI?
>
> That's the thing, everything related to the OS "BOOT" process is handled
> in software/firmware. I can't think of anything boot-related that would
> require a special HW logic.
>
> The only IML-related thing that requires a special HW is the
> E0000-FFFFFh range ROM/RAM switching, but that's implemented on the
> processor complex.
>
>> You must.. probe it! Yes!
>>
>> What pins of the FDC does it connect to? What other components does it
>> connect to?
>
> Yep... Probulation time!
>
>> How about this for an unsupported rumor... the DSKBOOT connects the FDC
>> to NVRAM to enable booting from CDROM... ;)
>
> :-D I like the enthusiasm, but that doesn't make much sense. The two
> components are already connected to the planar I/O bus. Not because they
> need to talk to each other directly, but because the CPU needs to be
> able to address both of them.
>
> Going by the little information we have currently, I only have one
> theory - the PAL handles the FDC reset initialization. The 82077
> controller can be switched between 3 different modes (PC AT, PS/2, and
> Model 30). This is done by setting two of the inputs in a certain way
> when the RESET line is toggled. I'll have to check the datasheet again,
> but I don't think this can be achieved with high value pull-up or
> something similar in this particular case. So perhaps "DSKBOOT" means
> "DiSK controller BOOT"? Though something like "FDCINIT" would make much
> sense in this context...

Huh, 64F3110 is connected to the FDC, the 85F0464 INT/KB/mouse ASIC,
maybe the FDC header, and possumbly the DBA-ESDI connectors [or at least
it WAS].

https://ardent-tool.com/9590/9590_Planar.html

U67 85F0464 ASIC (int/KB/mouse)
U72 64F3110, TI CF61533FN
U84 N82077AA Floppy Controller

Then I see a single line over to U68, a SIMMple logic, 74-series, I
think. U68 sendts a single trace up to 85F0464

https://ardent-tool.com/datasheets/Intel_82077AA.pdf

FDC reset initialization

Huh. So where is this on the Model 8595?

On 10/11
/2021 05:33, Tomas Slavotinek wrote:
> The 64F3110 PAL can be found on the following planars:
>
> https://ardent-tool.com/9590/9590_Planar.html
> https://ardent-tool.com/PS55/5560/5560.html
> https://ardent-tool.com/9533/9533.html
> https://ardent-tool.com/2011_2121/2121_Planar.html
> (the PS/1 stuff is unfinished and not listed on the Ardent Tool index)
>
> And possibly many more, since we don't always track the PALs/GALs and
> other glue...
>
> PS/1 hmm, unless it uses the PS/2 FDC mode, my theory is probably wrong.
>
> On 11.10.2021 12:00, Tomas Slavotinek wrote:
>> On 11.10.2021 1:47, Louis Ohland wrote:
>>> Please do. It makes me curious, blue. What is this PAL doing? Is it
>>> memory? Wired to the FDC, that doesn't seem quite sensible.
>>
>> Why not? The PAL is sitting right next to the FDC and at least some of
>> the traces go towards the controller.
>>
>>> Does it add function? DSKBOOT seems to suggest something related to
>>> booting,
>>
>> Yeah... the name. The "DSK" part makes sense - floppy DiSK, DBA DiSK -
>> could be either (or both) if we go just by the name itself.
>>
>>> not sure it is O/S related, more like IML? Maybe DSKBOOT supports DBA-ESDI?
>>
>> That's the thing, everything related to the OS "BOOT" process is handled
>> in software/firmware. I can't think of anything boot-related that would
>> require a special HW logic.
>>
>> The only IML-related thing that requires a special HW is the
>> E0000-FFFFFh range ROM/RAM switching, but that's implemented on the
>> processor complex.
>>
>>> You must.. probe it! Yes!
>>>
>>> What pins of the FDC does it connect to? What other components does it
>>> connect to?
>>
>> Yep... Probulation time!
>>
>>> How about this for an unsupported rumor... the DSKBOOT connects the FDC
>>> to NVRAM to enable booting from CDROM... ;)
>>
>> :-D I like the enthusiasm, but that doesn't make much sense. The two
>> components are already connected to the planar I/O bus. Not because they
>> need to talk to each other directly, but because the CPU needs to be
>> able to address both of them.
>>
>> Going by the little information we have currently, I only have one
>> theory - the PAL handles the FDC reset initialization. The 82077
>> controller can be switched between 3 different modes (PC AT, PS/2, and
>> Model 30). This is done by setting two of the inputs in a certain way
>> when the RESET line is toggled. I'll have to check the datasheet again,
>> but I don't think this can be achieved with high value pull-up or
>> something similar in this particular case. So perhaps "DSKBOOT" means
>> "DiSK controller BOOT"? Though something like "FDCINIT" would make much
>> sense in this context...

Intel has a listing for a PAL to be used on an ISA board under AT mode,
but nothing for PS/2 mode.

I wonder... if this PAL was used on DBA-ESDI systems for some reason.
The 9533 MIGHT have been designed for use with the 2.5" DBA-ESDI that
were used in the ThinkPad 700 720 ?

On 10/11/2021 08:21, Louis Ohland wrote:
> Huh, 64F3110 is connected to the FDC, the 85F0464 INT/KB/mouse ASIC,
> maybe the FDC header, and possumbly the DBA-ESDI connectors [or at least
> it WAS].
>
> https://ardent-tool.com/9590/9590_Planar.html
>
> U67 85F0464 ASIC (int/KB/mouse)
> U72 64F3110, TI CF61533FN
> U84 N82077AA Floppy Controller
>
> Then I see a single line over to U68, a SIMMple logic, 74-series, I
> think. U68 sendts a single trace up to 85F0464
>
> https://ardent-tool.com/datasheets/Intel_82077AA.pdf
>
> FDC reset initialization
>
> Huh. So where is this on the Model 8595?
>
> On 10/11
> /2021 05:33, Tomas Slavotinek wrote:
>> The 64F3110 PAL can be found on the following planars:
>>
>> https://ardent-tool.com/9590/9590_Planar.html
>> https://ardent-tool.com/PS55/5560/5560.html
>> https://ardent-tool.com/9533/9533.html
>> https://ardent-tool.com/2011_2121/2121_Planar.html
>> (the PS/1 stuff is unfinished and not listed on the Ardent Tool index)
>>
>> And possibly many more, since we don't always track the PALs/GALs and
>> other glue...
>>
>> PS/1 hmm, unless it uses the PS/2 FDC mode, my theory is probably wrong.
>>
>> On 11.10.2021 12:00, Tomas Slavotinek wrote:
>>> On 11.10.2021 1:47, Louis Ohland wrote:
>>>> Please do. It makes me curious, blue. What is this PAL doing? Is it
>>>> memory? Wired to the FDC, that doesn't seem quite sensible.
>>>
>>> Why not? The PAL is sitting right next to the FDC and at least some of
>>> the traces go towards the controller.
>>>
>>>> Does it add function? DSKBOOT seems to suggest something related to
>>>> booting,
>>>
>>> Yeah... the name. The "DSK" part makes sense - floppy DiSK, DBA DiSK -
>>> could be either (or both) if we go just by the name itself.
>>>
>>>> not sure it is O/S related, more like IML? Maybe DSKBOOT supports
>>>> DBA-ESDI?
>>>
>>> That's the thing, everything related to the OS "BOOT" process is handled
>>> in software/firmware. I can't think of anything boot-related that would
>>> require a special HW logic.
>>>
>>> The only IML-related thing that requires a special HW is the
>>> E0000-FFFFFh range ROM/RAM switching, but that's implemented on the
>>> processor complex.
>>>
>>>> You must.. probe it! Yes!
>>>>
>>>> What pins of the FDC does it connect to? What other components does it
>>>> connect to?
>>>
>>> Yep... Probulation time!
>>>
>>>> How about this for an unsupported rumor... the DSKBOOT connects the FDC
>>>> to NVRAM to enable booting from CDROM... ;)
>>>
>>> :-D I like the enthusiasm, but that doesn't make much sense. The two
>>> components are already connected to the planar I/O bus. Not because they
>>> need to talk to each other directly, but because the CPU needs to be
>>> able to address both of them.
>>>
>>> Going by the little information we have currently, I only have one
>>> theory - the PAL handles the FDC reset initialization. The 82077
>>> controller can be switched between 3 different modes (PC AT, PS/2, and
>>> Model 30). This is done by setting two of the inputs in a certain way
>>> when the RESET line is toggled. I'll have to check the datasheet again,
>>> but I don't think this can be achieved with high value pull-up or
>>> something similar in this particular case. So perhaps "DSKBOOT" means
>>> "DiSK controller BOOT"? Though something like "FDCINIT" would make much
>>> sense in this context...
>

On 11.10.2021 15:21, Louis Ohland wrote:
> Huh, 64F3110 is connected to the FDC, the 85F0464 INT/KB/mouse ASIC,
> maybe the FDC header, and possumbly the DBA-ESDI connectors [or at
> least > it WAS].

Looking at some more detailed photos, there are quite a few connections
between the PAL and the FDC - specifically data lines D0-7 and address
lines A0 and A1 (maybe more). This is part of the planar I/O bus, so
yes, if you see connections that go to the IO/INT controller, that makes
perfect sense as well...

> Huh. So where is this on the Model 8595?

On the 1S1P planar there's a PAL near the FDC as well, but it's a
different P/N.

On 11.10.2021 16:00, Louis Ohland wrote:
> Intel has a listing for a PAL to be used on an ISA board under AT mode,
> but nothing for PS/2 mode.
>
> I wonder... if this PAL was used on DBA-ESDI systems for some reason.
> The 9533 MIGHT have been designed for use with the 2.5" DBA-ESDI that
> were used in the ThinkPad 700 720 ?

It's possible that the PAL implements a few different functions that are
not directly related, but seeing that it's connected to the planar I/O
bus, it probably has nothing to do with the DBA interface (a subset of
the MCA bus, which has no place in the ISA-based PS/2 E and PS/1 systems).

How about this:

https://priorart.ip.com/IPCOM/000107744

That would explain the presence of the address/data lines...

And the following items are also a perfect match:

-"a transformer module consisting of a twenty-eight-pin design"
-"Diskette controllers, such as the 82077"

The only part that doesn't match is the date - 1992-Mar-01.
That seems rather late, it should be more in the 1989-1991 ballpark.

Here are some other more or less related TDBs:

https://priorart.ip.com/IPCOM/000110084
https://priorart.ip.com/IPCOM/000110375
https://priorart.ip.com/IPCOM/000110377
https://priorart.ip.com/IPCOM/000036919

On 11.10.2021 16:51, Tomas Slavotinek wrote:
> On 11.10.2021 15:21, Louis Ohland wrote:
>> Huh, 64F3110 is connected to the FDC, the 85F0464 INT/KB/mouse ASIC,
>> maybe the FDC header, and possumbly the DBA-ESDI connectors [or at
>> least > it WAS].
>
> Looking at some more detailed photos, there are quite a few connections
> between the PAL and the FDC - specifically data lines D0-7 and address
> lines A0 and A1 (maybe more). This is part of the planar I/O bus, so
> yes, if you see connections that go to the IO/INT controller, that makes
> perfect sense as well...
>
>> Huh. So where is this on the Model 8595?
>
> On the 1S1P planar there's a PAL near the FDC as well, but it's a
> different P/N.
>
> On 11.10.2021 16:00, Louis Ohland wrote:
>> Intel has a listing for a PAL to be used on an ISA board under AT mode,
>> but nothing for PS/2 mode.
>>
>> I wonder... if this PAL was used on DBA-ESDI systems for some reason.
>> The 9533 MIGHT have been designed for use with the 2.5" DBA-ESDI that
>> were used in the ThinkPad 700 720 ?
>
> It's possible that the PAL implements a few different functions that are
> not directly related, but seeing that it's connected to the planar I/O
> bus, it probably has nothing to do with the DBA interface (a subset of
> the MCA bus, which has no place in the ISA-based PS/2 E and PS/1 systems).
>

On 10/11/2021 10:02, Tomas Slavotinek wrote:
> transformer module

On 11.10.2021 17:44, Louis Ohland wrote:
> On 10/11/2021 10:02, Tomas Slavotinek wrote:
>> transformer module

Patent speech at its best...