John Foust wrote: I can't recall either, but that brings to mind an interesting project a friend of mine worked on quite a few years ago. The Art Museum here was having some kind of show and an artist wanted to paint electronic pictures. My friend designed the electronics (I built the circuit boards) to put a line of LEDs on a pendulum and paint pictures electronically as the pendulum swung through its arc. With the multi-colored and higher intensity LEDs available today, it would be really cool to do the same thing but with color pictures. Doesn't sound like too hard a project especially with the speed of todays computers.

Four things: a) Computer Speed has never been a problem (at least not within the last 20 years) b) Colour _is_ a problem, since the colour sensivity of the human eye isn't exactly great. c) Moving pictures are way harder to produce d) And most important the mechanical parts are the challenge. If you like to get an accaptable detailed picture, like, let's say a colour TV (up to 200 lines (aka ~400x400 pixles)) the simple setup is gone, since you have to swing the mechanism with a continous speed of at least 20 passings per second in front of a non disturbing background. Beside all mechanical problems, the most simple solution would be a propeller like device, where you either only use a rectangular display area (2x1) in the upper rotation area, or a square area all over. This adds some drawbacks: You have to calculate all x/y pairs to a circular position with _different_ on/of timing according to the position, while still producing circular artefacts (in contrast to linear artefacts, as with TVs or simple horizontal moving devices, circular are _very_ disturbing). Beside that you ma produce a noticable noise: 2 wings (to halve the needed speed, while still maintain a low storage profile (not to speek of better balance)) moving at 10 rounds per second (20 passings for each location per second) with a diameter of 1m (giving a visible area of .7m x .7m) produce a speed of 113 km/h at the end of each rod - quite notable. The only advantage of this would be a way less complicates mechanical design (no fast acceleration on bothe ends of the movement needed). Anyway, this technology will never take of. The only version with a possible use is if you mount the LEDs on a helix like curve to produce real 3D pictures - but again, a Laser and a semitransparent full helix is more aprobiate. These swinging displays are dammed to stay at low res (almost) static display levels. Gruss H. -- VCF Europa 2.0 am 28./29. April 2001 in Muenchen http://www.vintage.org/vcfe http://www.homecomputer.de/vcfe

On Tue, May 09, 2000 at 11:43:28AM -0700, Mike Ford wrote: I'd like to know where the heck to get one of these for "around" $100. I'll whip out my card and buy one RIGHT NOW. 8-) Bill -- +--------------------+-------------------+ | Bill Bradford | Austin, Texas | +--------------------+-------------------+ | mrbill(a)sunhelp.org | mrbill(a)mrbill.net | +--------------------+-------------------+

Am I the only one that knows how to use a search engine, BTW shoot me if I am off a silly zero or so. http://www.MicroOpticalcorp.com/ Following link in other post, Omron made the unit I looked at during WCES.

On Tue, 9 May 2000, Marvin wrote: Go to Union Station in Downtown LA. There's a display consisting of eight to ten columns of LEDs (each column being about 3-4 feet high and actually consisting of a combination of red, blue and green (sound familiar) LEDs) If you look at it dead on, it just looks like blinking lights. But if you sweep your eyes across it, you'll see pictures of trains, traffic, celebrities, etc. This is near the "Patsouras Transit Plaza/Vignes" exit of the Metro Red Line subway.

Perhaps Firewire's a distant decendant of the DEC CI780 and HSC50 disk interface SDI cable. Bill -- bpechter(a)monmouth.com | Microsoft: Where do you want to go today? | Linux: Where do you want to go tomorrow? | BSD: Are you guys coming, or what?

I believe SDI = Serial Disk Interconnect (or something like that). They're the cables from the HSC50 or UDA50a to the RAxx drive. bill -- bpechter(a)monmouth.com | Microsoft: Where do you want to go today? | Linux: Where do you want to go tomorrow? | BSD: Are you guys coming, or what?

On Tue, 9 May 2000, Ron Hudson wrote: See http://www.imsai.net and click on the IMSAI Series Two link. Sellam

On Wed, 10 May 2000, John Wilson wrote: Actually it's unprecedented. As far as I know this is the first example of a company coming out of hibernation (according to Todd IMSAI never really ceased to exist) and offering a new model of an obsoleted computer product line. If there are any other examples of this I'd like to hear about them.

On Tue, 9 May 2000, Mike Ford wrote: Hmmm, perhaps I should've said "COMPUTER company". Radios don't count in a classic computer discussion ;) Sellam

On Wed, 10 May 2000, Mike Ford wrote: Compare... ...and contrast. ;)

I don't know the answer to this one. No, it's all run by hardware. It uses the voltage and timing conventions that are laid down in the 8080 manual. (They are the same conventions that the CPU uses to communicate with memory and peripherals.) Essentially the control panel intercepts the signals that would normally be sent automatically by the CPU or memory. I don't think it lets you do input and output, but theoretically you could do that too. With enough hardware you can do some pretty fancy stuff. The Mark 8 lets you give instructions to the CPU that don't come from anywhere in memory. (The CPU thinks they do, but they don't.) The PDP-12 lets you stop the computer if certain things happen (i.e., your program branches to a certain part of memory). There are also limitations to the hardware approach. For example, the 8080 in the IMSAI doesn't easily make the contents of its internal registers available, so you can't manipulate them with the control panel (except for the program counter). You could change that with enough work, but I don't know if anyone has. Newer CPUs have been designed to make this sort of hardware snooping easier, but they're still limited (you can only check for a certain number of conditions at the same time, for example). Heath made a computer (the H-8) which is similar to the IMSAI but actually does use a program to control the computer along with the usual hardware. The H-8 is a lot newer than the IMSAI, however. -- Derek

On Wed, 10 May 2000, Bob Brown wrote: The H8 is nothing like the IMSAI. The H8 runs a rom program to give teh disply/keypad some intelligence (not much). HAve you checked with HEATH (or whatever their name is this year)? If not check around as they were common enough and someone can copy the docs. Allison

On Tue, 9 May 2000, Ron Hudson wrote: Effectively not for many years. There was no rom in the base imsai. The frontpannel was all hardware and worked by inserting wait states in the instruction flow effectively stopping the micoprocessor at every cycle. Allison

Only one instruction I think maybe jump and maybe nop. The reads and writes to the pannel was more majik. The data bus displayed whatever data was at the current location (or on the bus. To write a location all you had to do was create a write pulse and gate the data onto the DO bus. Most of the logic was single step(cycle) and single instruction Vs "run" state. I know this as I did a z80 machine with simpler STD like bus and made a cp for it. It was mostly buffering the LEDS and gating the switches to the bus and some simple timing logic (I used Clocked D and JK FFs rather than oneshots). The WAIT/ line on the Z80 did all the work. The worst part of building it was drilling/mounting/wiring 28 leds! Allison

As the number of expansion slots in a PC approaches zero, the marginal propensity to use something else increases. Of course you have to consider the candidates. There's always that old PC/AT that hasn't been fired up in a few years. There's that stackable PCI stuff. ... and, of course, there's that old S-100 or Multibus-1 box that's been languishing in the closet in the downstairs spare bedroom since '82 or so. Control and telemetry tasks haven't really gotten to be much more demanding over the 20 years intervening, so maybe one of those options should be considered. Yes, you could build hardware to attach to your notebook's EPP port, but do you really want to wed your notebook to those tasks for lengthy periods? Yup! That ol' S-100 box could fill the bill nicely. Even if you just need an SBC like the ones from Intel (for Multibus) or for S-100 from SD Systems, et. al. Think about it! Even an old PDP11/03 would be a candidate, right? Dick ----- Original Message ----- From: Eric Smith <eric(a)brouhaha.com> To: <classiccmp(a)classiccmp.org> Sent: Wednesday, May 10, 2000 2:01 PM Subject: Re: s100 busses!

Allison wrote: I suspect a lot of them did. In 1983, Johnson County Community College in Overland Park, Kansas received a donation of a PDP-8/e system with third-party RK05 clones, which had been retired from running the scoreboard at one of the stadiums across the border in Missouri. I was tasked with trying to figure out some practical use for the machine. None of my proposals were accepted; admittedly they weren't really very practical, since by that time microcomputers were much more suited to most educational needs. The machine was apparently scrapped. :-(