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IBM 6901 "Personal Typing System"

NeXT

NeXT

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Oct 22, 2008
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Kamloops, BC, Canada
I saw this on a shelf when I was doing side shopping on my vacation, minus the keyboard, monitor and printer.

the-ibm-personal-typing-system-is-designed-for-secretaries-who-a-a-picture-id517352120


Spec wise it is identical to the PS/2 model 30 because inside the case turned 90 degrees is a model 30 planar. The expansion cabinet contains the 72X6757 External floppy adapter and two unused ISA slots. A quick googling seems to indicate it will work with those IBM 4869 external 360k 5.25" floppy drives that everyone seems to have at least one of but never the interface card.
The CMOS battery is a Panasonic BR-2/3A lithium cell. I have spares.

The first time I turned it on it complained about the date and time and then tried to boot off the hard drive which is one of those blasted IBM proprietary ones. It sounds fantastic with no nasty fluttering or whining noises however it gave itself a few attempts and then hung at a blinking cursor. When rebooted while the drive did its seek test it gave a 1701 error. Awesome. I don't have any more of the narrow edge connector drives. I gave my last one away last year because I didn't expect to ever need it.
I grabbed the Starter diskette and Advanced diagnostics diskette for the model 30 from here and ran through everything once I replaced the battery. One thing I noticed is that it keeps trying to handle the external floppy as if it is a 720kb drive so it never works properly. The other is that I can get the hard drive to respond to some of the tests but they still all fail with "UNDETERMINED ERROR". I know with the later wide edge connector drives there's a few SMD caps that you need to replace but on these older drive they are miniature radials. The machine and the drive seem so immaculate I dare say it is a cap issue.

This page has more picture and says it has Monochrome CGA, however I've seen it do color and it uses an HD15 VGA port.
Anyways without a hard drive I can't proceed any further. Anyone got any ideas on what is up with the external drive?
 
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Hey, I actually had a 4869 that came with an adapter card in a PS/2 Model 50. I say adapter because the card seemed to be entirely passive.....it plugged into one of the unused floppy connectors.

Also, it looks like this thing used standard IBM PS/2 era VGA monitors. That looks like a 8512
 
It very much is a standard monitor. This just seems to be a really, really oddball machine IBM insisted existed for word processing instead of just...slapping a new badge on a model 30.
I feel like this is the equivalent to the 486SX-25 where it was blowing money into a market which didn't even need a specialty machine.
 
As I expected.

I checked all the miniature radials with an ESR meter and all but one failed to go above "FAIR" on the meter. Most were sitting in "BAD". More than likely the drive is so misbehaved is because it requires a full recap.

Here is a list of required capacitors required for the logic board on the IBM EDI-325Q (IBM P/N: 61X8785)

16v 47uf - 2 (C1, C2)
6.3v 100uf - 1 (C8)
16v 6.8uf - 5 (C10, C12, C13, C14, C28)
16v 4.7uf - 2 (C7, C15)
 
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MCGA is basically crippled VGA. It has the same CGA emulation and 256-color 320x200 graphics mode (used by tons of DOS games), but text mode has one fewer pixel column per character cell (640x400 instead of 720x400 -- not a huge difference), there is no EGA emulation, and 640x480 VGA graphics mode is strictly monochrome (as in literally black and white -- no grayscales), even on a color display.
 
Thanks to our good friends at The Hackery, I have been supplied a replacement hard drive that hopefully let me finish testing the machine.
Also trying to run diagnostics with an IBM 4869 repeatedly resulted in tests failing. It tries to behave with the drive but keeps on trying to apply 720kb 3.5" formatting, so I assume it wants an external 3.5" floppy drive instead of an external 5.25" drive. Incorrect ROM option perhaps? Anyways, The Hackery should be help me with this as well.
 
NeXT said:
Thanks to our good friends at The Hackery, I have been supplied a replacement hard drive that hopefully let me finish testing the machine.
Also trying to run diagnostics with an IBM 4869 repeatedly resulted in tests failing. It tries to behave with the drive but keeps on trying to apply 720kb 3.5" formatting, so I assume it wants an external 3.5" floppy drive instead of an external 5.25" drive. Incorrect ROM option perhaps? Anyways, The Hackery should be help me with this as well.
Click to expand...

I suspect that since 5.25" drives were initially viewed as an aberration by the PS/2 engineers, a 3.5" drive expansion box is what's intended. Still, there has to be an underlying operating system (MS-DOS?), so it should be possible to override the 720K default.
 
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