On the subject of oddball PC media, does anyone out there have media for
the DTC "Take Ten" cartridge drive? I've got the drive here, still in
original shrink-wrap and packaging, but no media, so I don't have the
faintest idea if it still works.
As the 5.25" cartridges only held 10MB, I suspect this was a
flash-in-the-pan venture. I'd never heard of one back in the day when
everyone was using Bernoulli drives.
--Chuck
Orihalcon sells nifty Soarers converter cables that let you use most
terminal keyboards on a PC. But please be aware that ONLY the keys found on
a normal PC keyboard will work! You can do some remapping, but F13-F24 will
not be available, and some keys will not operate the same as they did on the
original keyboard. I have used these to test Wyse (with removable cables),
IBM, and a bunch of AT and XT keyboards. They do not work for ADDS
keyboards.
Cindy Croxton
Electronics Plus
1613 Water Street
Kerrville, TX 78028
830-370-3239 cell
sales at elecplus.com
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Yesterday I dug out my prototype IBM DemiDiskette drive and took some
photos: https://twitter.com/TubeTimeUS/status/1032066215647166464. It
caused a bit of interest on Twitter so I figured some of you here may also
like seeing it.
I don't really know a whole lot about it other than what my grandfather
told me (he worked on the team that developed it). Dates on the remaining
paperwork go from December 1979 through August 1980. It was supposed to be
a very low cost drive for the microcomputer market (target price IIRC was
<$100). Although it was originally developed by a team working at IBM
Austin, it was handed off to a different team apparently working out of
Rochester.
The disk capacity was not very large--I don't remember the exact number but
it was probably around 100K or less.
A few interesting observations:
* The stepper motor uses a spiral cam to convert rotation into linear
motion to drive the head.
* It is a single-sided drive.
* A microswitch senses the presence of the disk instead of an optical pair.
* There is no write protect notch or sensor.
* There is no index sensor.
* The spindle drive motor is a DC brushed motor with an encoder wheel for
speed control.
* Not shown in the pics, but the plastic "spot welds" holding the vinyl
jackets on the disks are intentionally widely spaced making the cookie
easier to remove for analysis.
It's not really something you get to see every day, that's for sure...
--Eric
Why don't you simply power it through an inverter that will output 60 Hz, eventually even "down to" 120 V , true sine wave, of course ??? They are not that expensive by now.
And be carefull : motor designed for 60 Hz, running "under" 50 Hz, OR THE OPPOSITE, I do not recall !!!, display a significant reduced life time.
I have to check which is which, but I know this is a question of saturated magnetic field. Better check first.
More sorting, more boards.....
3) DATARAM 40818 (ONE IS ? POPULATED)
2) EMC CORP 240-010-900 512KB
EMC CORP 240-012-900 4MB
MOSTEK MK8044 ASM 6805
MOTOROLA MM19 ? POPULATED 1 BROKEN CHIP
NATIONAL SEMI 551109202
PLESSEY 701295 128KB HAS BROKEN CHIPS
STANDARD MEM MM-144
TRENDATA STANDARD MEM MM-135
2) TRENDATA STANDARD MEM MM-140
I got a box of miscellaneous model M keyboards last week. One of them
has 122 keys and the connector is the size of a PC/AT type circular
DIN connector, but the 5 pins are spread over 240deg instead of the
AT's 180deg. The part no. is 1390702 and a little research found it is
>from an IBM 3192 terminal.
Is it electrically/protocol compatible with the PC/AT and PS/2
keyboard or a different animal completely?
-chuck
I'm sure it's been years since I've darkened anyone's door around here.
I still have this idea that someone should write a proper BBS system (and
run it) for RSTS...
...the age old problem is getting data in and out of it to connect it to
the world... or one of the problems anyhow. Maybe using a telnet
connection to a terminal device and some sort of homebrew message queueing
system to an outside helper.
Hmmm.
I finally got my package of cling vinyl today and discovered that it is
indeed the stuff the vinyl open-reel tape retention strips were made of
in the days of yore.
The stuff is Grafix-brand "Cling Vinyl", KFC9-ASST. 9 9"x12"
paper-backed sheets. Easy enough to cut with scissors or standard paper
cutter. 6" long x 3/8" wide seems to be about right.
No more foam blocks!
--Chuck