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IBM 5110 initial info

voidstar78

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I've begun exploring into a working IBM 5110.

Notes and photos available at...

IBM 5110 Notes
https://voidstar.blog/ibm-5110-notes/


I'd like to explore if a tape interface for this system could be emulated (like on a smartphone). The IBM 5110 Computer Maintenance Information manual, available online, seems to have sufficient information on the interfaces. [ or perhaps emulating the whole disk drive system itself ]

Any notes about this old system is appreciated. (such as approximate production numbers - one number I came across for the Commodore PET was about 5000 units/yr, I would suspect the 5110 was less then that)

Also, a confession: I haven't figured out how to remove the expansion cards (like the PALM processor itself). I tugged a little bit, but they didn't come out, so I didn't want to risk anything more aggressive. I thought these cards were know to just "fall out" on their own.


Thanks! (wasn't sure if this should go in pre-Altair section or the PC-section, so I ended up posting this here)


https://voidstar.blog/ibm-5110-notes/
 
One question I have is:

does anyone know what these internal switches do? (images below) The metal rocker switch is labeled "RUN" (on a sticker towards the front, not photo'd). The white push button switch is some kind of reset (I don't think it is depressed when the case is back on, since otherwise the case would impact the rocker switch). I know the front of the 5110 has a reset switch, maybe this white switch is just an alternate way to reset in case the front panel is not available for whatever reason (looks like it's part of the same wiring as the front reset switch).



Also, I think it's fun that the 5110 uses these same types of "cloth labels" as is found in the later 5150 IBM PC. Is there some other more official designator of these labels/tags?


On two of these labels have a reference to "WATER INST INC", does anyone know what that is about?


Thanks!





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In IBM PC 5150 model B from 1984... (near the speaker)

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"WATER INST INC" should be "Water Instruments Incorporated" or some such, the company that made that particular piece of the wiring harness. The bottom line of the 5150 label (below the "FEBRUARY 1984") lists the manufacturer of that piece of wiring in a similar manner.
 
Hi VoidStar78

You may find it useful to watch the restoration videos that dealt with a 5120 - the YouTube channel is 'Jerry Walker'. The videos were perhaps a year ago.

I believe the 5120 used the same or similar circuits to those in the 5110. The chassis was different in style to accommodate a somewhat larger display. I recall having located documentation referring to the 5120 on a website in Germany.

You may need to be patient, but there are other 5100, 5110 and 5120 owners 'out there'. I'm sure the questions you asked will find good answers in time ...

Regards
 
5100 driver here. In re internal switches: the toggle switch puts the PALM processor into single-step mode, where you clock the processor through a step by pressing the white button.

If I had to guess, "WATER INST. INC" could be the name of a subcontractor... Water Instruments Incorporated? No idea otherwise.

There is a "Waters Instruments Inc." in Rochester, MN (where the 51x0 series was made), but that seems like a coincidence?
 
Thanks for the note about the switch being a single-step mode.


Today, I've added two sections in my notes: more details about the expansion cards, and also "screenshots" of the ROS(ROM) built in diagnostic tools

EDIT: I also "discovered" another label/tag near the power supply.



I'm trying to make sure I have the expansion cards understood correctly. Specifically, there is this "half length" card between what I think is the PALM(CPU) and RAM - I'm not sure what that is. Maybe it is a "video card" or display processor of some sort? And I'm not sure if the BASIC ROS ("Common and Language ROS") really consumes two slots, or if there is something else there.



And, I understand now that a 5106 tape drive won't work - at least, not by itself. There is some additional (or alternate) expansion card or ROS needed to drive that (apparently the same one used to drive the internal tape drive, so I can't just add an internal tape drive either without having that board with the appropriate ROS -- any dead 5110's with spare parts out there? :) ). So might have to study the back connectors and figure out a disk emulator (I'm not sure which port is IEEE-488, or is all of them collectively that interface? that odd "tri-connector" at the back)


Any notes on other things to do with the Diagnostic tool? That "A" command seems to make it into a built in assembler. And I don't fully understand the BRANCH commands yet, but didn't spend too much time with it. (I'll see if the online 5110 emulator models this ROS content and experiment there)


Thanks for the YT notes, will check it out.


EDITED: revised diagram

IMG_7859B.jpg
 

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Does the diagram on your blog post help answer some of your questions... that is, this one here? Judging from the diagram, one of the labeled BASIC/common ROS cards is actually for display, while the mystery short card is for the Feature ROS (don't know what that is, I don't think it's on the 5100...) and the two full-width RAM cards are actually two half-width RAM cards and one full-width card holding the executable ROS.

Those three funky-angled D-sub ports on the back are all part of the same expansion connector --- you can find pinouts in the MIM. I'm pretty sure that's not IEEE-488; perhaps that's instead what the "Parallel I/O" card facilitates. That card seems not to be fitted in your photo.

What card is missing that you need for the tape drive?

On another note, do you know why your 5110 has a keyboard with APL symbols but no APL? BASIC-only 5100s don't usually have APL symbols on the keycaps.
 
As I understand it, the IBM 5100 was available with BASIC, BASIC and APL and just APL. The ROS modules were split up so you would not get the BASIC ROS or BASIC IO Executable ROS if you only got the APL version and vice versa. The 5110 came with BASIC built in on all of them and APL was an option. Hence why there is no specific BASIC ROS but rather a Common ROS. The Feature ROS was also "common" so included the BASIC bits.

You probably know this already but card locations are essential. You can switch around like cards like the memory cards but nothing else because these cards have the same part number. The diagram here tells you where they go. On each card, there is a part number. I've circled them in red in the picture below. The first 7 numbers are the part number and these will usually match with the Logical Card Part Numbers section of the MAP (Maintenance Analysis Procedure manual). I have one or two cards with newer or older part numbers that don't match up in some cases. Since yours works, you are fine. If you just got it and weren't sure, you could use this info to help locate what cards go where.

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Installing an internal tape drive is a problem because the wiring is different. It's also different for BASIC/APL machines as there is no wiring for the BASIC/APL switch. The "three D" connector on the back is for connecting an external tape drive or dual disk drive. You could daisy chain these and would need a terminator at the end (it had a three D connector too.

You removed the screws for a cutout in the back. This is where you mounted additional optional functionality. One of my 5110's had a DB25 connector there for serial communication. There is an extra card for that needed to add the functionality. I think it's in slot D and is noted on the diagram as the "Asynchronous Comm-Serial IO' board. I do believe IEE-488 was also an option but I have not seen that one myself.

From your pictures, you don't have a BASIC/APL keyboard. It just supports BASIC.

This one is BASIC/APL. It has more legends on the key caps for multiple functions.

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Hope this helps a little,
Santo
 
Right, I had to study that diagram for a bit. Attached is an overlay of what I currently have arranged in my 5110 (color boxes), and the A1 board diagram from the IBM manual.

Seems what have does line up (I thought it was off one slot, except the processor, but my mistake - I'll update the notes, it's not two RAM cards {the two cards at the end have quite different components}).



I assume the Executable ROS is like the core system stuff (invoking startup checks, offers the diagnostic program, etc). Still not sure what the Feature ROS is all about (tentatively it doesn't look like it has a lot of components on it -- I'm still not ready yet to try pulling any cards out).



As for the APL symbols - are you sure? The black labels on the front of the keys are BASIC commands (DIM, CHAIN, MAT, NEXT, GOTO, etc). I don't have like square and triangle symbols, that I think APL uses.



You're right about the IEEE-488 support, per the GeneralInfo and Planning manual: (on the Commodore systems, they had disk drives through the IEEE 488, so I was hoping something there could be retrofitted to the 5110 -- but seems we have to source or replicate these parallel I/O adapter cards)

****
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******





As for the tape support, I guess it's not so much a missing card, but missing ROS content. Two points:

From the IBM manual (General Info and Physical Planning):
"Tape storage: Various models of the 5110 have a built-in tape unit. The tape cartridges have a storage capacity of 204,000 characters (bytes) of information. An auxiliary tape unit can also be attached to the 5110s that have a built-in tape unit" (i.e. if you have the built in tape, you can add an auxilary unit -- otherwise, nope).

And from one of the online German computer history museums:
"The external IBM 5106 tape drive is identical to the one built in the IBM 5100 and IBM 5110 Model 1, and it can only be attached to these models as the 5110 Model 2 and the 5120 lack of some logic on the Base I/O card and perhaps some routines in ROS"

So, sounds like I can't just find an internal tape and plug it into the TAPE port (Z2). Sounds like revised "Base I/O" and "Executable ROS" cards might be needed - unless the info is wrong, or the '79 Model 2 cards just happened to have that ROS content.


But the "Base I/O" I have should support the disk drives. Making my own "triple-D" plug won't be too fun :)





EDIT: updated attachment/diagram to reflect that I do have the I/O Cable Driver card in slot A.



cards.jpg
 
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Just to add a bit more info, attached is a picture of a 5100 on the left and a 5110 on the right. Between the keyboard and screen are key labels for the upper row. On the right, there are two rows. One row is for APL and one is for BASIC. On the left are three rows. One for APL, one for BASIC and one for Communication (this one has the serial port). It's an easy way to see what functionality an IBM 51xx has. The dead giveaway is the forth toggle switch on the top right of the face next to the screen but the keyboard function label helps as well.

twoIBM5100.jpg
 
So, sounds like I can't just find an internal tape and plug it into the TAPE port (Z2). Sounds like revised "Base I/O" and "Executable ROS" cards might be needed - unless the info is wrong, or the '79 Model 2 cards just happened to have that ROS content.

You are right. On further reading, there is a 5110 X1X model (with tape drive) and X2X (without tape drive). The Logical Card Part Numbers section in the MAP manual shows different cards per slot. I guess the X2X has floppy disk routines and the X1X does not.

Santo
 
...You removed the screws for a cutout in the back. This is where you mounted additional optional functionality. One of my 5110's had a DB25 connector there for serial communication. There is an extra card for that needed to add the functionality. I think it's in slot D and is noted on the diagram as the "Asynchronous Comm-Serial IO' board. I do believe IEE-488 was also an option but I have not seen that one myself...

I opened that panel again, to explore more behind that yellow cable that covers the opening. I didn't try too hard (for fear of unplugging something), but that yellow cable sure doesn't move a whole lot. But I could tell there are no other connectors behind that cable (on my 5110). So aside from just adding the Async Comm Serial Board, seems like one has to open up the PSU to also route these additional connections (probably twisting or moving this yellow ribbon cable in the process). I imagine it's the same situation for the Parallel I/O card - that a "special connector" would have to be routed thru the PSU and over to this access panel. (so it's like a Mac- you better order what you really want upfront, because no one is going back in there :) )




And for APL - a thought was one could just "drop in" an APL card (which, from the diagram, is that a "half length" card?). The 5110 Model 2 won't have the BASIC/APL toggle switch (up front), so not sure how to trigger the ROS to enter into that APL mode (might not be able to - might need "matching APL Executable ROS" to go with it?). Any photos with a 5110 model 1 opened, where does the APL/BASIC switch tether over into?




I'd suspect the "Command and Language ROS" has some of the System/3 or System/370 emulation stuff? so the APL add-on would "borrow" some of the Common capability, perhaps? (like both languages probably have ability to print text to the screen - do they invoke something on the Display, or do they go through some Common ROS call?)
 
Well, if anyone still happens to have a 5106 tape drive (or knows a place), with cable (and terminator?) - would still like to give it a try. I see a block diagram in the IBM manual that is giving me a vibe that the external tape drive might work on a Model 2 (and the "other" IBM manual section saying it won't work: it's an intro section, and perhaps remained just to discourage Model 2 owners from trying tape and focus instead of the $$$ disk drives? I wouldn't put doing such a thing past IBM)

Meanwhile while looking for a 5106 tape drive, we'll try a ROS/ROM dump of the Model 2, see how they compare to a 5100 or 5110 model 1.
 
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Do the letters at the startup of the 5110 correspond to the expansion slots? I assumed so, since the letter omit "i" (which is also omitted in the manuals).


But the manuals also only go up to N. So what is P?


And if you omit "i" then P is the 14th entry (even starting at 1 instead of 0). So then what is "ROS 15" ? (what's the 15th ROS?)


Maybe the ROS count "ROS 15" includes the "i"? Or some expansion slots hold two options instead of just 1, maybe the ROS index accounts for that.


And what is the "X2" and "X4" in the IBM manual A1 board diagram? I assume it's some bandwidth increase (x2 rate, x4 rate) between those components?


Then one more question: should I just remove the black "rubber" thing that is between the PALM processor and the BASE I/O card? It appears to just be some kind of spacer. Is it just a "stopper' to help keep the cards from coming out when hanging? I've seen this rubber-whatever-it-is deteriorate in other 5100s (maybe from storage outside of A/C rooms, from heat?) - mines rather ok, but there might be specs of some kind of growth started in it.



ROS_indexes.jpg
 
Do the letters at the startup of the 5110 correspond to the expansion slots? I assumed so, since the letter omit "i" (which is also omitted in the manuals).

No relation. "I" is usually removed so people don't confuse it with "L" or "1" when reporting things. That's why "O" is not there either (confused with "0")

These are "bring up diagnostic" tests. As noted in the IBM 5110 MIM manual there is a table. The middle column tells you what position card is tested. The right column tells you what is on screen when that test has passed. There is more information about these tests in the manual.


5110diags.jpg


So then what is "ROS 15" ?

That is Error number 015 in the ROS at the current test as indicated by the test letters showing at the top of the screen. You can usually find those error codes in the MAP manual and see what the issue/diagnosis is.


And what is the "X2" and "X4" in the IBM manual A1 board diagram?

These denote the board jumpers between boards. The CPU board has two of them. I am guessing X2 and X4 denotes that the jumpers are different circuitry.


Then one more question: should I just remove the black "rubber" thing that is between the PALM processor and the BASE I/O card? It appears to just be some kind of spacer. Is it just a "stopper' to help keep the cards from coming out when hanging? I've seen this rubber-whatever-it-is deteriorate in other 5100s (maybe from storage outside of A/C rooms, from heat?) - mines rather ok, but there might be specs of some kind of growth started in it.

It's a spacer. Clean it and leave it there. it will outlast you. What your 5110 doesn't have is the foam pad that the closed card cage rests on. This turns to a sticky tar and yours is already removed. You are lucky if it was already done before you got it. If you had to removed it, you know what I mean. You can see a picture of it here: https://vintagecomputer.ca/wp-content/uploads/2015/03/IMG_20150312_142533.jpg

Hope this helps,
Santo
 

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Thanks, I missed that in the MIM. Are the cards divided into 4 sections? Like "K4" is the 4th section of the K-slot? (like I see "M2 through N4", although I don't see an M1 listed)




That is Error number 015 in the ROS at the current test as indicated by the test letters showing at the top of the screen. You can usually find those error codes in the MAP manual and see what the issue/diagnosis is.

Oh in this case, I don't think it's an error code. I mean, using Norbert's 5110 emulator as a reference, on power up the system cycles through ROS 1, 2, 3, 4, 5, ... "1B"... "41" (I didn't catch that it was hex until just now). And the letters at the top "grow" from ABCDEFGH to ABCDEFGHJKLMNOP (and then Q, as noted in your diagram - the "Q" goes very quick, would have to video it back in slow motion). So I think the ROS is normal startup stuff. I did have a fault show up once, and some error code I think showed up at the bottom of the screen - but I just did a reset and haven't seen the fault again since. I'll grab a shot of it it happens again, since I'm not sure if Norbert's emulator readily supports emulating faults (maybe the core engine can, just no ready interface to induce them).


There is another "X4" marked between A and B slots. There are 7 dots on the X4's and 5 dots on the X2's, maybe that corresponds to some number of pins. Can check next weekend.



In the image below, "A" marks an example of the "growth" I was a little concerned about. I guess it's just deterioration, not bacteria :) I'm not sure how hot it gets in there (or has gotten) -- it seems the fan just serves the PSU area, and doesn't do much for these circuits (just given the way things are wrapped around).

With the "A" part removed, the "B" part remains to keep the cross connection between the two cards. (point being that without the rubber part A, I'd still have a spacer part B). The "A" rubber bits get a little sticky.


spacernotes.jpg





I've started a little bit thru that MAP manual now. I wonder what they wrote that in (to make all the vertical lines). 250 pages, bless them for doing it. On MAP 050-6, I noticed the following:

What's this Auxiliary Tape Unit Adapter Card? It is a "card" that is part of the Executable ROS Card?


auxtape.jpg
 
Like a couple of old gentlemen, taking it easy, sipping some cassette data.


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(boot up sequence video IBM 5110 Model 2 standard startup sequence on RESET - YouTube just to show the ROS cycling before the BASIC prompt )


5150: "You know what I admire most about you?"
5110: "Well, I'd guess either the REVERSE switch or that I can process faster if you disable my screen output?"
5150: "Nope, it's your spacebar. So steady, on both sides."
5110: "Indeed, how is it you ended up with that seesaw spacebar of yours?"
5150: "Rumor says, I was dropped during birth..."
5110: "Well, that explains a lot. I'm tired now, think I'll nap a bit more."
 

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