Re: Keyboard inverters/converters for terminals
3.0" drives (Amdek, Amstrad, etc.) use same connectors as "standard"
5.25", with "molex" power connector (I don't know what the CORRECT name is
for that connector).
On Fri, 22 May 2020, Pete Turnbull via cctalk wrote:
It's part of the AMP (now TE) Mate-N-LOK series.
But, I have some 3.25" drives that use same connectors as "standard" 3.5"
drives, ("4 pin Berg"?) EXCEPT 5V and 12V are swapped in their positions
in the coneectors!
Not Berg, not even the same pitch. They're AMP Economy Interconnect
connectors, with a 2.50mm pitch.
THANK YOU.
Seriously.
The pedantic nature of this list makes it a real treasure.
Simple GOOGLE and Wikipedia are buried in too many "definitive" wrong
answers. Such as calling 36 pin Blue ribbon "Centronics", "DB9", or the
historic/antique uses of the yellow and black pair in phone wiring (NO, it
was NOT "always" for second line)
--
Grumpy Ol' Fred ci...@xenosoft.com
Re: Keyboard inverters/converters for terminals
On 22/05/2020 17:21, Fred Cisin via cctalk wrote:
#> 3.0" drives (Amdek, Amstrad, etc.) use same connectors as "standard"
5.25", with "molex" power connector (I don't know what the CORRECT name
is for that connector).
It's part of the AMP (now TE) Mate-N-LOK series.
But, I have some 3.25" drives that use same connectors as "standard"
3.5" drives, ("4 pin Berg"?) EXCEPT 5V and 12V are swapped in their
positions in the coneectors!
Not Berg, not even the same pitch. They're AMP Economy Interconnect
connectors, with a 2.50mm pitch.
--
Pete
Pete Turnbull
Re: Keyboard inverters/converters for terminals
On Fri, May 22, 2020 at 6:21 PM Fred Cisin via cctalk wrote: > > On Fri, 22 May 2020, Tony Duell wrote: > > Of course plugging an RS232 cable (DB25, none of this DE9 nonsense!) > > into a PC printer port (or a PC printer cable into an RS232 port) is a > > good way to let magic smoke out of some TTL chips... > > IBM tried to use the [INADEQUATE] protection of opposite gender. Which > won't help if there is a sufficient pile of random other cables, A lot of manufacturers, including major ones used the wrong gender of connector on their RS232 ports... A socket wired as a DTE is common. The HP150 is a classic... HP did just that (2 serial ports, wired as DTEs, but sockets on the main unit). There was an option board which included a parallel port. It used a DB25 _plug_. But it gets better, The PCB was clearly designed for a DB25 socket, which would have had a pinout compatible with the IBM parallel port. It appears that at the last moment HP changed to a plug (I guess so you couldn't plug the official HP cables into the wrong connectors). The result is that the pins are mirrored compared to IBM, strobe is on pin 13, Data 0 on pin 12, etc... -tony
Re: Keyboard inverters/converters for terminals
On Fri, 22 May 2020, Tony Duell wrote:
Of course plugging an RS232 cable (DB25, none of this DE9 nonsense!)
into a PC printer port (or a PC printer cable into an RS232 port) is a
good way to let magic smoke out of some TTL chips...
IBM tried to use the [INADEQUATE] protection of opposite gender. Which
won't help if there is a sufficient pile of random other cables,
OR, college administrators purchasing "gender-changers" for adding a
second parallel printer! (on slot 8 of the 5160)
(For those not familiar, IIRC, slot 8 of the XT/5160 has differences in
buffering; to avoid accidental misuse, IBM provided the XT with a "free"
RS232 card to fill up that slot)
Later, when they got 286, 386, 486, and Pentium machines, they dug out
their gender-changers to see whether the parallel printer would work on
any male DB25 connectors on those machines. I wonder if THAT is why IBM
switched from DB25 to DE9 for serial port.
DE9 was used for 5150 CGA and MDA (not quite compatible)
AND for the early Microsoft "Bus mouse"
and, with opposite gender for "modern" RS232 ports.
DA15 was used for 5150 analog input (joystick) and
some people use it as a specialized video connection.
And, of course, the 5150 used 5 pin DIN for both keyboard AND cassette.
On the back, out of sight. ("MY left, or YOUR left?")
TRS80 [model 1] had used THREE 5 pin DINs on the back and side by side
for power, video and cassette.
"Sentience is the ability to learn from misteaks; wisdom is the ability to
learn from somebody else's previous misteaks."
Around here, IBM never had a cable available for cassette, but the Radio
Shack #26-1207 worked.
Re: Keyboard inverters/converters for terminals
On Fri, 22 May 2020 at 18:21, Fred Cisin via cctalk
wrote:
>
> Similarly, I have a few 3.25" drives. NO, not 3.5"; not 3.0". 3.25" was
> the entry in the "shirt pocket disk" wars that Dysan bet the company on.
> (remember their disks?)Another discussion.
I remember the Zenith Minisport, a DOS laptop with 2" floppies:
http://oldcomputers.net/zenith-minisport.html
Don't think I ever saw one in real life, though.
Not sure any other computer ever used those media.
I own a number of Amstrad devices with 3" disks. But I don't think I
ever saw 3¼"!
> OB_Tangent: Georgre Morrow said that the solution would be to cut a deal
> with clothing manufacturers to make shirt pockets 5.25" or even 8"
Ha! :-)
It is a bit funny that people issued diktats, and designed products,
about and around pocket sizes.
Now I am doomed to ridiculously-thin phones with poor battery life.
This device was roundly mocked:
https://www.businessinsider.com/energizer-phone-with-huge-battery-failed-on-indiegogo-2019-4
It's about the same thickness as the original hard-disk-based iPods,
which sold in the tens of millions and were regarded as a pinnacle of
miniaturisation. I think our list member Mr Corlett was the first to
note that, that I saw.
> 3.0" drives (Amdek, Amstrad, etc.) use same connectors as "standard"
> 5.25", with "molex" power connector (I don't know what the CORRECT name is
> for that connector).
With some adjustments, anyway, I believe...
https://www.cpcwiki.eu/index.php/DIY:Floppy_Drives
> But, I have some 3.25" drives that use same connectors as "standard" 3.5"
> drives, ("4 pin Berg"?) EXCEPT 5V and 12V are swapped in their positions
> in the coneectors!
:-o Nasty!
--
Liam Proven – Profile: https://about.me/liamproven
Email: lpro...@cix.co.uk – gMail/gTalk/gHangouts: lpro...@gmail.com
Twitter/Facebook/LinkedIn/Flickr: lproven – Skype: liamproven
UK: +44 7939-087884 – ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
Re: Keyboard inverters/converters for terminals
> But, I have some 3.25" drives that use same connectors as "standard" 3.5"
> drives, ("4 pin Berg"?) EXCEPT 5V and 12V are swapped in their positions
> in the coneectors!
I have an Archive Sidewinder tape drive on one of my PERQs. The power
connector is the same as a 5.25" floppy drive power connector but the
2 voltages are +5V and +24V. At least the +5V pin is where you expect
it.
I am told some Sun workstations (Sun 2's???) had a power harness to
feed both 5.25" drives and a Sidewinder. The only dfference between
the connectors was the colours of the wires going to them.
Of course plugging an RS232 cable (DB25, none of this DE9 nonsense!)
into a PC printer port (or a PC printer cable into an RS232 port) is a
good way to let magic smoke out of some TTL chips...
It didn't let any magic smoke out, but I once had to sort out a
10base2 ethernet system that was behaving very oddly. Putting a 'scope
on the cable showed a signal the likes of which I'd never seen on
ethernet before. I cranked the timebase down and recognised it.
Composite video (RS170-like). Some 'genius' had plugged an unused
ethernet T-piece into the BNC connector on the back of a VT220...
-tony
Re: Keyboard inverters/converters for terminals
On Fri, 22 May 2020, Liam Proven via cctalk wrote:
Ha!
I have an old external 3.5" IDE disk enclosure. It's a good enclosure,
too -- Firewire 800 _and_ USB 2 _and_ eSATA. It has the internal drive
from my old iMac G5 in it. The iMac suffered from failing capacitors
and I coaxed a little more life from it by making its HD external.
I wish to retrieve its contents.
It has a very odd power connector. It's a DIN plug with quite a few
pins -- 7 or 8 and a plastic locator. Unique PSU.
As I have been on mandatory working-from-home for a couple of months,
I took my Mac mini setup in the bedroom apart and stashed the bits
away, and set up
my work laptop with 2 old external screens as a home office. One
ancient Eizo screen and a slightly more modern HDMI one.
Snag: I failed to pack the modern HDMI screen's PSU brick away with it.
This led to a lot of frantic hunting. I found the power brick, and some others.
The snag is this. I now have _two_ power bricks for the external
drive. Both deliver the requisite *both* 12V and 5V. Both have the
right DIN plug and fit.
But they're wired differently. One's ground pins are the other's 12V pins.
I think this is now resolved but it was an interesting question: one
brick will power the drive, while the other, with an identical
connector, is more or less guaranteed to release the magic smoke from
the external enclosure.
Similarly, I have a few 3.25" drives. NO, not 3.5"; not 3.0". 3.25" was
the entry in the "shirt pocket disk" wars that Dysan bet the company on.
(remember their disks?)Another discussion.
OB_Tangent: Georgre Morrow said that the solution would be to cut a deal
with clothing manufacturers to make shirt pockets 5.25" or even 8"
3.0" drives (Amdek, Amstrad, etc.) use same connectors as "standard"
5.25", with "molex" power connector (I don't know what the CORRECT name is
for that connector).
But, I have some 3.25" drives that use same connectors as "standard" 3.5"
drives, ("4 pin Berg"?) EXCEPT 5V and 12V are swapped in their positions
in the coneectors!
Re: Keyboard inverters/converters for terminals
On Fri, 22 May 2020 at 05:26, Rico Pajarola via cctalk wrote: > > > The whole concept of "if the plug fits, it will at least not blow up" is > kind of a late invention. Ha! I have an old external 3.5" IDE disk enclosure. It's a good enclosure, too -- Firewire 800 _and_ USB 2 _and_ eSATA. It has the internal drive from my old iMac G5 in it. The iMac suffered from failing capacitors and I coaxed a little more life from it by making its HD external. I wish to retrieve its contents. It has a very odd power connector. It's a DIN plug with quite a few pins -- 7 or 8 and a plastic locator. Unique PSU. As I have been on mandatory working-from-home for a couple of months, I took my Mac mini setup in the bedroom apart and stashed the bits away, and set up my work laptop with 2 old external screens as a home office. One ancient Eizo screen and a slightly more modern HDMI one. Snag: I failed to pack the modern HDMI screen's PSU brick away with it. This led to a lot of frantic hunting. I found the power brick, and some others. The snag is this. I now have _two_ power bricks for the external drive. Both deliver the requisite *both* 12V and 5V. Both have the right DIN plug and fit. But they're wired differently. One's ground pins are the other's 12V pins. I think this is now resolved but it was an interesting question: one brick will power the drive, while the other, with an identical connector, is more or less guaranteed to release the magic smoke from the external enclosure. 樂 -- Liam Proven – Profile: https://about.me/liamproven Email: lpro...@cix.co.uk – gMail/gTalk/gHangouts: lpro...@gmail.com Twitter/Facebook/LinkedIn/Flickr: lproven – Skype: liamproven UK: +44 7939-087884 – ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
Re: Keyboard inverters/converters for terminals
On Thu, May 21, 2020 at 10:20 AM Eric Smith via cctalk < cctalk@classiccmp.org> wrote: > IMNSHO, there's a special place in hell reserved for those who have > designed equipment to (ab)use modular connectors other than for telephone > lines and 10BASEx Ethernet, and I really think a better connector should > have been chosen for 10BASEx. > The whole concept of "if the plug fits, it will at least not blow up" is kind of a late invention. And I'm amazed when this actually holds true in situations where I wouldn't quite expect that to be the case (e.g. all those electrically not quite compatible PCI/PCI-X/PCIe variants that have coded notches to prevent you from frying your computer/card. Except that you can stick a PCI card backwards into a PCIe slot) DEC using MMJ may get a pass because they at least attempted to prevent > connecting the wrong stuff together. > Any ideas why it took so much longer for keyboard interfaces to converge than most other peripherals? Display interfaces, HDDs/floppies/tapes etc., serial ports, and even mice converged on only a few variants more or less the moment they became commonplace. I'd really like some first hand insight into why anyone would want to invent a new interface/protocol from scratch every time they start developing a new machine (I'm mostly talking about the "simple async serial protocol sending up/down events" kind). Luckily there are only 12 different ways to wire a 4P4C, but there exist way more incompatible keyboards using that connector. Is it really easier to develop an incompatible serial keyboard interface from scratch than to re-use one that already exists? [actually, I kinda know, because of course it's easier to do a one-off and not care about documentation, licensing, extensibility, or forwards/backwards compatibility]
Re: Keyboard inverters/converters for terminals
On Thu, May 21, 2020 at 9:37 AM Electronics Plus via cctalk < cctalk@classiccmp.org> wrote: > https://www.vecmar.com/products/search.asp > Type in keyboard > The first result allows a terminal keyboard to be used on a PS/2 port. > The second result allows a PS/2 keyboard to be used on a terminal. > >From the limited information available (almost none), it appears that they are selling passive adapters that work with ADDS 4000 terminals that use PS/2 protocol on a modular jack. As has been noted earlier in this thread, there are a huge number of computers that use modular plugs and jacks for keyboard interfaces, and there is NO standard for their electrical or protocol characteristics. Plugging in the wrong combination can result in damage to either or both devices. Even using the wrong modular cable can do that, because common 4P4C modular cables are wired with a flip (1 to 4, 2 to 3, etc), while modular cables for computers are sometimes (e.g. Macintosh 128/512/Plus) wired straight through (1 to 1, 2 to 2, etc.) IMNSHO, there's a special place in hell reserved for those who have designed equipment to (ab)use modular connectors other than for telephone lines and 10BASEx Ethernet, and I really think a better connector should have been chosen for 10BASEx. DEC using MMJ may get a pass because they at least attempted to prevent connecting the wrong stuff together.
Keyboard inverters/converters for terminals
https://www.vecmar.com/products/search.asp Type in keyboard The first result allows a terminal keyboard to be used on a PS/2 port. The second result allows a PS/2 keyboard to be used on a terminal. Not affiliated with seller, etc. Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 830-370-3239 cell sa...@elecplus.com -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
