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NF6X
September 9th, 2014, 10:31 PM
I'm not sure whether this even counts as a computer, but it looks pretty interesting, and I'll be picking it up this weekend! It's an IBM Mag Card II Typewriter (https://en.wikipedia.org/wiki/IBM_Selectric_typewriter#Selectric-based_machines_with_data_storage). I found this video on Youtube (https://www.youtube.com/watch?v=H92dJbp-KNM) of the card reader in operation on one of these. I think this machine will take the crown for being the least practical machine in my collection, but I'm looking forward to digging into that fascinating card reader!

20406 20407 20408

I already have some blank mag cards for it. If I can find any documentation for it, or even some old used cards with unknown contents, that will be really cool.

MikeS
September 10th, 2014, 07:44 AM
As you say, not very useful today but definitely cool!

I've got a couple of readers left from a Redactron system and exactly one card, contents unknown if you want it.

m

m_thompson
September 10th, 2014, 08:26 AM
The Rhode Island Computer Museum has two of them. One looks like yours, and one is an earlier model.

http://www.ricomputermuseum.org/Home/small-systems-at-ricm/ibm-magcard-ii-selectric-typewriter

Chuck(G)
September 10th, 2014, 09:21 AM
Let's also not ignore the predecessor, the IBM MT/ST (http://en.wikipedia.org/wiki/IBM_MT/ST) magnetic tape typewriter. A few years ago, I passed on an opportunity to pick one up--it was just too darned big and heavy.

NF6X
September 10th, 2014, 09:47 AM
As you say, not very useful today but definitely cool!

I've got a couple of readers left from a Redactron system and exactly one card, contents unknown if you want it.

m

I'm interested in that card! Wanna trade for it?

I hadn't heard of the Redactron before. Based on a quick googling, I gather that it was roughly comparable and contemporary to the IBM machines in the Mag Card II's lineage.


The Rhode Island Computer Museum has two of them. One looks like yours, and one is an earlier model.

http://www.ricomputermuseum.org/Home/small-systems-at-ricm/ibm-magcard-ii-selectric-typewriter

Thanks for sharing the link here. That's one of the very few references to my new machine that I found while googling.



Let's also not ignore the predecessor, the IBM MT/ST (http://en.wikipedia.org/wiki/IBM_MT/ST) magnetic tape typewriter. A few years ago, I passed on an opportunity to pick one up--it was just too darned big and heavy.

Discussion of the predecessor(s) and descendant(s) of this machine are also quite welcome in this thread as far as I'm concerned!

I think I'm getting this machine at a very nice price (http://www.ebay.com/itm/251635373104). I expect to spend more than that on fuel when I pick it up this weekend. :)


I gather that the Mag Card II operator can record and play back fixed text, with stop codes inserted where variable text should be manually inserted, the type ball should be changed, etc. So, not a Turing-complete machine from that perspective, but what about the innards? I wonder whether it's implemented as a fixed state machine that performs those operations, or if it executes some sort of firmware or microcode?

I'm also curious about whether I'll be able to nondestructively tap into the signals in such a way that I might subvert this machine into doing duty as a hard copy terminal, or to read/write cards via some sort of computer interface.

The card drive is what I'm most curious about in this machine, but maybe something else in there will also capture my interest. If its design philosophy is anything like what I've seen in my 5322 Datamaster, then I'll expect the innards to appear quite opaque without having any documentation available.

Chuck(G)
September 10th, 2014, 10:02 AM
Do check in on the Golf Ball Typewriter Shop group on Yahoo groups (https://groups.yahoo.com/neo/groups/golfballtypewritershop/info). There's some interest there--and quite likely some maintenance information.

NF6X
September 10th, 2014, 12:16 PM
Do check in on the Golf Ball Typewriter Shop group on Yahoo groups (https://groups.yahoo.com/neo/groups/golfballtypewritershop/info). There's some interest there--and quite likely some maintenance information.

Thank you! I've applied for membership. I see that there's already a recent topic about the very typewriter that I bought, so I'll pop in there as soon as my membership is approved.

g4ugm
September 10th, 2014, 01:07 PM
Hi, I a;lso have e of these. Mine doesn't work at present it has a broken drive belt :-(

Chuck(G)
September 10th, 2014, 01:29 PM
Hi, I a;lso have e of these. Mine doesn't work at present it has a broken drive belt :-(

Yeah, the &@#! stupid drive belt. I've got a nice Correcting Selectric III with that ailment and haven't the courage to tackle the repair.

NF6X
September 10th, 2014, 01:36 PM
In my quick skim of the recent Mag Card II thread on the golfball forum, I saw discussion of the drive belt(s), their regional variations, and their non-standardness. I hope that my machine won't have similar belt issues.

I wonder if anybody has looked into replacing sprocket wheels with ones that can accept more common belts?

Chuck(G)
September 10th, 2014, 07:08 PM
What would be perfect would be one of those segmented timing belts that you can just snap together. Taking the machine apart to replace a rubber belt just sucks...

mfriethm
September 15th, 2014, 06:21 AM
We've got one of the IBM Executive mag card typewriters buried somewhere. Last I knew, it typed fine, but had issues with reading/writing the cards. It was a nice machine, though, in that it did proportional spacing. Used it in high school for typing a bunch of reports (or mostly my Mom typed them for me!). I'd be interested in hearing how you revive your machine. I might have to take a stab at this one soon...

NF6X
September 15th, 2014, 07:38 AM
I didn't know that there was a mag card variant of the Executive. Neat!

I picked up the Mag Card II on Saturday. The seller also threw in a couple of plain Selectrics (a I and a II) for use as parts, and I think I'll want to give those away once I'm sure I don't need anything else from themů I have so much junk! :)

I haven't had much opportunity to mess with the Mag Card II yet over the weekend, but I did open up the card reader cabinet. One of the rubber shock mounts for the card reader sheared off, and that may well have been my fault, as the cabinet rode on its side in the back of my truck and I live on a rough dirt road. So, it got a good shaking in a bad axis. Overall, the innards of the card reader look pretty good, and the belts appear to still be intact. The system will need lots of cleaning before I try applying power. The typewriter is missing one of the margin level sliders and one of the lenses over the status lamps.

A poster on the Selectric collectors group mailing list indicated that it's not difficult to nondestructively hack in a computer interface of some sort, so maybe I'll be able to do weird and interesting things with this machine. I have no intentions of doing any destructive hacks on it.

NF6X
September 15th, 2014, 07:50 AM
Oooh! I was just told that the margin slider probably isn't missing from it; it should just have one slider for the left margin, with the right margin being set electronically. Those two plain Selectrics are even closer to my trade list now!

g4ugm
September 15th, 2014, 01:13 PM
I was thinking of trying to repair my broken belt as I have a UK model and the belt is a different length...
... and seemingly unobtainable...

NF6X
September 15th, 2014, 01:27 PM
I haven't looked at the belt(s) in my typing unit yet. The flat belts in the mag card reader look intact, though at least one of them looks a bit frayed along one edge. So, I may or may not need to figure out how to procure or fabricate replacements. At least the flat belts ought to be easier to kludge than a custom timing belt.