I have two IBM Model 5150s (one original rev, and a rev b). I think I've
explored every single inch of the hardware except for light pens -- I would
really like to experiment with one and write some software that interfaces with
one. Does anyone know:
1. What light pens were available and for which PCs? (I also own Tandy 1000s,
and they have "light pen" ports too)
2. Does anyone have any light pens for sale or trade?
I've already tried googling and searching usenet -- the only references I can
find are companies selling light pens for modern machines, and tech info that
states the obvious (ie. "The IBM PC supported a light pen"... yeah, thanks :-)
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
Done completely in Flash. Pretty damn amazing:
http://myoldmac.net/webse-e.htm
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
>From: "woodelf" <bfranchuk at jetnet.ab.ca>
>
>Dwight K. Elvey wrote:
>
>>Hi
>> I've always been looking at using a DSP chip for this job.
>>I did expect to read parts of a track at a time and then
>>reassemble them as condensed data. Chips like the Analog
>>Devices 2181 have some 80Kbytes of onboard RAM. Although,
>>it can't all be used for storage at the same time and
>>some is needed for program space. These chips can be
>>implemented with a real minimum of outside circuits.
>>they even have a serial SPI that can be used to read
>>disk data at higher speeds. These processor run at 30 MIPs
>>plus. They can run some operations, such as data moving
>>to arrays in single cycles, including updating of pointers.
>>They can do as many as 5 operations in a single cycle.
>> The can bootstrap from simple slowspeed EPROM of FLASH.
>>One could easily connect one of these to that USB chip
>>that someone pointer to earlier.
>>Dwight
>>
>>
>>
>Look what you are doing is building a generic floppy disk controler.
>The only high speed device what you use to sync the data/clock pulses
>to the system cpu clock. The rest is software. I'd sooner use a CPLD
>designed for generic bit sampling but a PIC would also work with
>a digital data/clock seperator. Now would getting the people who do
>cat-weasel create a USB version be a better goal?
>Ben alias woodelf
>PS. What about hard-sectored floppy disks, that too may need reading
>too?
Hi
I think you are missing what I am saying. The SPI is just
a shift register that takes an external clock. It can be programmed
to automatically DMA transfer into memory. It is the perfect zero
additional logic circuit to use. You don't need to build a
data/clock separator or anything. Just sample the data.
One could even make the output SPI provide write data. These
chips are designed to load their programs from a single
flash or EPROM so the entire hardware requirement is almost
nothing.
I see others on comp.os.cpm talk about using a 50MHz variant
of a Z80. I think most miss the point. These DSP's are 30 MIPS+
not just 50 MHz clocks. They have enormous capabilities in
a relatively small package. It was like they were designed for
this project. You don't need to create a CPLD since the hardware
part is already done for you.
Dwight
Maybe a little OT, but..
I just laid hands on a Friden EC-130 calculator, and I'll be darned if I can figure out how to take the top cover off of it.
The cover *seems* to come off by sliding forward, but there are a pair of pins in the rear that keep it in place. I've tried to flex the cover enough to clear the pins, but the resistance encountered is more than I am comfortable with.
How does this thing come off?
--
---------------------------------------------
-. William W. Layer .- -. St. Paul, MN USA .-
---------------------------------------------------
-. Cheif bottlewasher, Atma-Sphere Music Systems .-
-. http://www.atma-sphere.com .-
--------------------------------
Hi All,
after a few days frustration, I have got a little further with my 11/45.
The power supplies checked out OK with respect to ripple and output, but a
couple have them have the odd VERY fast spike on them - is this normal? (I'm
using a 100MHz 'scope - I suspect they may not be visible on a slower one).
After reducing the machine to its basics, I found I could load an address
>from the front panel, but not write or examine any location successfully.
The address and data lines became active, but the processor then goes into a
pause state. I found that the MSYN line was not being asserted, and it
appears that one ic on the Unibus controller (M8106) is not providing the
correct ouput - grounding the scope probe will force the line, and the
processor completes its bus cycle (Yes the inputs to the ic are correct!).
I have found a spare serviceable UBC, so I'll try that when I next get
chance, and if that fixexs the fault, I'll repair mine.
Jim.
Please see our website the " Vintage Communication Pages" at WWW.G1JBG.CO.UK
On Mar 19 2005, 23:43, Jules Richardson wrote:
> We couldn't get it to work with any transceiver we tried (SQE test
was
> off, FWIW), whether hooked up to a hub or not - it still gave a
> complaint about heartbeat at startup and then subsequent "no carrier"
> errors (and the "Ethernet jammed" errors).
The complaint about "heartbeat" is because the interface is expecting
to see the SQE test appear a few bit times after the end of the frame.
"Ethernet jammed" might mean it's seeing a continuous jam signal, or at
least sees a jam signal when it listens to the wire to see if it can
transmit. A jam signal is what a repeater puts on the wire when it
detects a collision (and it would see the SQE test signal as a
collision). It's an alternating set of 1s and 0s that lasts 96 bit
times, as I recall (an ordinary station can also generate a jam signal
but not such a long one), and the object of that is to force everything
to see a collision and back off. Now it so happens that 96 bit times
is also the interframe gap length, so if you have a repeater with a
transceiver set to do SQE tests, it sends an SQE test starting a few
bit times into the IFG, then generates a jam which will still be there
slightly after the end of the IFG, just when the station might be
checking for carrier again. Have you got another repeater somewhere
with a transceiver on it? Or are you missing a terminator so that the
voltage is out of spec and might look like a collision?
> As said in a private mail just now though, we'd had this problem with
> our PDP 11/84 - on the advice of an ex-DEC chap, it'd only talk to
one
> of these DEC units rather than any kind of AUI-equipped hub (or a
> transceiver). On a whim we tried the same with the Sun, and it seems
to
> have improved matters.
I've had various DEC machines, like my 11/83, attached to both
thickwire and thinwire with non-DEC transceivers and never had a
problem. I do check the SQE test, though :-)
--
Pete Peter Turnbull
Network Manager
University of York
>
> > > 2. Does anyone have any light pens for sale or trade?
> >
> > No, but it's not hard to make one if you don't require high resolution.
> > There was at least one design in 80-micro for the Tandy 1000. There were
> > plenty of designs for the Beeb (most of them use the Honeywell 'Sweet
> > Spot' devices). Thoese were not as good as the Torch one I mentioned, but
> > they do work.
>
> There are a couple on ePay at the moment, too.
It may be worth mentioning that microcomputer light pens tend to be
somewhat interchabeable.
They need either +5V, +12V, or both as power, The actual light pen signal
is a pulse that occurs when the light pen detects light from the CRT
screen, it's almost always TTL level, and the only possible problem here
is that it's the wrong polarity, which can be trivially fixed with a
74x04 inverter. If there's a pushbutton switch on the light pen, most
likely it just grounds the appropraite wire when pressed.
DEC lightpens (at least the one on my GT40) are different. They're just the
phototransistor, the amplifier, etc, is inside the display. Microcomputer
lightpens tend to put the electronics in the pen or its interface box.
-tony
On Mar 19 2005, 21:32, Jules Richardson wrote:
> The Ethernet card may be a source of trouble. It seems to want
something
> that provides an external heartbeat - we hooked up a DEC hub to get
> around that problem, which stopped the "no carrier" messages on the
> console. However, it's still throwing up "Ethernet jammed" messages -
> and ideas what that's about?
Have you got the "SQE Test" turned on on your transceiver? You have to
turn it off if you have the transceiver connected to a repeater (which
is probably what your DEC hub is). What the SQE test does is send a
test signal after every frame, to test the collision detect circuitry,
but the repeater will see this as a real collision and will send a jam
signal.
--
Pete Peter Turnbull
Network Manager
University of York
A friend has a large number of 3-1/2" HD diskettes with IBM Filing
Assistant files on them.
Does anyone know of a way to open and read those files so that they can be
brought in to a current database program or spreadsheet?
Jay wrote:
> Yeah, I'll give you a primer on the capacitors on the TU56.... to get
> replacements is about $70 each! For the four motor run caps anyways.
>
> I'll get to refurbing my TU56 "Someday".
I hope to bring my TU56 back to life this year too ...!
One note on the ### motor capacitors.
AFAIK there is a difference between motor *start* caps and *run* caps.
If I am wrong I would like to know, else what is the difference?
- Henk, PA8PDP.
