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Is this an S-100 chassis?

NF6X

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A friend is offering me this chassis with a couple of 8" floppy drives in it. I would want it for the drives in any case, but maybe I can find a use for the whole thing. Does this card cage look like an S-100 bus to y'all?

I won't have the unit in my hot little hands for a couple weeks or so. When I do, I'll study it in more detail. If it's an S-100 chassis, then I may be interested in trying to find cards to turn it back into a functioning computer.

computer01.jpg computer02.jpg
 
Hi Mark,

An S-100 board is 10 inches wide.
Also, the 100 pin edge connector is offset 1 1/2 inches from one edge of the board and 2 1/8 inches from the other edge.
If you make these dimensions, it is very likely that you have some sort of custom-built S-100 chassis.
Anyway, once you get a hold of it, make sure that you check out the voltages and grounds. If those also match up with the S-100 "standard," you are probably good to go.

Sigh... Some guys get all the luck! ;-)

smp
 
Its not a good picture of the cage but it looks like the Cromemco cage they sold for custom/industrial applications, if so yes it's an S100 buss.

Cromemco is and was very proud of their name - and if it is a Cromemco buss it will have their logo on it.


Randy
 
It's impossible to tell if the cardcage is S-100 from the angle in the photos.

But, the construction looks similiar to that of many enclosures that were manufactured by Integrand Research here in CA in the 1980s and 1990s.

Integrand manufactured from the bottom up, designing and building the transformers and circuit boards that went onto the power supplies they built, and they did custom enclosures for other bus based computers and in custom colors as well as standard colors that they stocked. They sold a multitude of S-100 enclosures and disk drive enclosures. They even dabbled in PC Enclosures for Industrial and Rackmount PC Compatibles for a time before going out of business.

I can't see the power supply. If the power supply is a commercial unit, the complete mainframe is not an Intgerand, since they built they own power supplies. But someone could have bought the Integrand mainframe without the power supply, or had a special order design built, and purchased without a power supply.

Integrand enclosures were primarily sheet aluminum, and they had the ability to bend some pretty heavy stock. Many mainframes (not rackmounts) feastured wrap around covers for the bottoms and tops that wrapped around onto the sides. Most competing S-100 enclosures and disk enclosures were fabricated/bent primarily from much thinner sheet steel.

The extra cooling fan bolted onto the end of the cardcage was a feature of their "supercooled" series, and an optional for some of their other designs.

The front panel does not look like an Integrand, but the front panel is made so it can be easily replaced (Intergrand offered custom design front panels for it's products).

If the mainframe you get is not S-100, you can still probably convert to use with S-100 by replacing the cardcage and motherboard with S-100 compatible parts (and reconfiguring or replacing the power supply). Looks like a high quality enclosure and Mitsubishi M-2896-63 1/2 height 8" dsdd floppy drives. Definitely a Keeper!

If the Mitsubishi floppy drives don't work, they may be repairable, and would probably be worth repairing. Heck, if the mainframe is an Integrand, I might be interested in buying it from you, if you don;t have a use for it. I can service the drives for you if necessary. I have a couple of M2896-63 drives that have been retired with bad heads that I'm using for parts to repair other Mitsubishi drives, or I'd be interested in buying them from you for a few bucks to be repaired or used for parts.

Michael
 
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No. No you're not. :)

Since I have seen a number of racks like that I would guess it was a process control system, some would be blank plates others interfaces to control industrial equipment under control of that chassis.

The rack would be developed by one company and all panels painted to match each other.


Randy
 
I've learned that the other cabinets have long since been gutted and turned into drawers. It all did come out of some old manufacturing equipment. Hopefully I can acquire the box with the floppy drives soon, and I'm crossing my fingers that there's an S-100 cage in there. If not... then, I can always find a use for more 8" floppy drives.
 
That's too bad. If it's an industrial thingummy, I suspect that the odds are less than even that it's S100. Multibus and proprietary buses were more common in industrial applications. Still, not beyond the realm of possibility.

The prevailing view among major manufacturers was that S100 has too many design deficiencies. Multibus, with a regulated power supply (instead of lossy linear regulators on each board) and negative bus logic is a bit more rugged.
 
That's too bad. If it's an industrial thingummy, I suspect that the odds are less than even that it's S100. Multibus and proprietary buses were more common in industrial applications. Still, not beyond the realm of possibility.

The prevailing view among major manufacturers was that S100 has too many design deficiencies. Multibus, with a regulated power supply (instead of lossy linear regulators on each board) and negative bus logic is a bit more rugged.

While many process control systems were other busses there were lots of S100 ones also - Cromemco had a good slice of that pie.

If you have ever seen a Cromemco system two you would know it is very happy in an industrial setting, plus cromemco had a line of industrial offshoots including a small S100 open frame cage and their single card computer to go with it.

I serviced some Cromemco's in a couple concrete plants and a huge paper mill.


Randy
 
I've owned a Cromemco system, but S100 was a lousy bus for industrial applications, particularly when compared to Multibus or VME. S100 had severe drawbacks in its design.

Still, the first application of a microcomputer to industrial process that I saw was probably 1977, an Imsai 8080 running a plastics vacuforming machine. If the rig in question is something put together by a small outfit, I'll grant that it could well be S100. But a 100-position edge connector doesn't automatically mean S100--I can show examples of both a non-S100 backplane and boards using the 100 position edge connector.
 
I've owned a Cromemco system, but S100 was a lousy bus for industrial applications, particularly when compared to Multibus or VME. S100 had severe drawbacks in its design.

Still, the first application of a microcomputer to industrial process that I saw was probably 1977, an Imsai 8080 running a plastics vacuforming machine. If the rig in question is something put together by a small outfit, I'll grant that it could well be S100. But a 100-position edge connector doesn't automatically mean S100--I can show examples of both a non-S100 backplane and boards using the 100 position edge connector.

I have seen a medical experimental lab that used an S100 buss based cards - they used the buss for power and interconnections but all the boards were custom wire-wrapped cards.

I have seen S100 computers in small process control work (Cromemco).

I have seen S100 computers in huge high end process control work (Cromemco).

Yes I have seen process control on many busses and many processors (the 1802 a favorite for really harsh environments).

Don't be fooled the S100 was a lot more common than you believe.

At one point almost every decent sized city had Cromemco computers for their TV weather - they used the a VAR based SDI setup for the graphics. I would bet some smaller stations still have them.

Just remember the movie Wargames showed an Imsai, which was mocked up with most of the S100 cards with their card edge connectors cut-off (cries a little here) but they used a Compupro in the background for all the graphics.

The S100 has touched a lot of areas.


Randy
 
Look, I know about S100 stuff--I built my MITS 8800 in 1975 and still have it. What struck me even then, was the lack of common-sense engineering involved. The big advantage was that, compared to the well-engineered stuff on the market, it was cheap.

Can you imagine Sun Microsystems bringing out an S100 box?
 
Look, I know about S100 stuff--I built my MITS 8800 in 1975 and still have it. What struck me even then, was the lack of common-sense engineering involved. The big advantage was that, compared to the well-engineered stuff on the market, it was cheap.

Can you imagine Sun Microsystems bringing out an S100 box?

The Altair started as three boards wired together with no bus. The bus was created when sales orders came rushing in. They were able to buy a bunch of 8080 chips with blemishes at a huge discount and quickly made the S100 bus warts and all.

Comparing a SUN to an S100 computer is more than unfair, the SUN is basically a single-board computer with some I/O expandability.

A bussed based system can never compete with the speed of a single-board computer like a PC or the SUN. A bus adds so much downside but has a huge high side. Try changing the basic type of processor in a SUN or a PC.

S100 is much better as a hobbyist system because all it's short falls are upsides for a hobbyist.


Randy
 
I've learned that the other cabinets have long since been gutted and turned into drawers.

Ahh, that's a shame. Guess we will never know if it contained a prototype flux capacitor now :)

The Altair started as three boards wired together with no bus. The bus was created when sales orders came rushing in. They were able to buy a bunch of 8080 chips with blemishes at a huge discount and quickly made the S100 bus warts and all.

The 100 pin connectors were there right from the start. The boards were certainly not directly wired together. Initially it was called the Altair bus before the clone makers adopted it and it became known as the S100 bus. Very little thought was given to the organisation of the pinout other than to save vias on the CPU board.

Comparing a SUN to an S100 computer is more than unfair, the SUN is basically a single-board computer with some I/O expandability.

The early Sun 68k machines were built around Multibus. Yes, they had some RAM and I/O onboard but so do some S100 CPU boards.
 
looking at the first photo after rotating it, I see the date on the floppy is 4-12-94

llGhQPH.jpg


a tad hard to make out the rest of it.

But the word Working on lh side of floppy label probably means disk was copy of a system one back then.

When you get it hopefully the rest of the floppy label text may give you some really good clues on what it was.
 
...
Comparing a SUN to an S100 computer is more than unfair, the SUN is basically a single-board computer with some I/O expandability.

Hmmm, the original Stanford University Network (SUN) machine was 68K on Multibus. Even as late as the Sun4/3xx systems there was only cache RAM on the VME CPU card; I have one such system here with 32MB in four 8MB cards (populated with a metric ton of 41256 DIPs). Multibus was very common in the router space; the original cisco boxen were Multibus, as were the Proteon boxen. 68000, 68020, and 68030 were common in that space.

The S-100 bus is and was a lousy industrial bus; Cromemco (and others) took a lemon and made lemonade. Now, IEEE-696-1983 was a vast improvement, and, again, Cromemco made some fantastic products (topping out with the XXU 68020 CPU card, used even in military applications). But in terms of actual bus design Multibus and VME are far better for the electrically noisy industrial environment. As much as I like the TRS-80 Model II line, the Model II bus would have been a lousy industrial bus, too.

A bussed based system can never compete with the speed of a single-board computer like a PC or the SUN. A bus adds so much downside but has a huge high side. Try changing the basic type of processor in a SUN or a PC.

Actually not hard to do in an old SUN. This is exactly what happened between the Sun 3/xxx and Sun 4/xxx systems; many cards were upward-compatible in those early VME systems.

S100 is much better as a hobbyist system because all it's short falls are upsides for a hobbyist.

The same can be said for ISA passive backplane systems. S-100 was early and became ubiquitous in the CP/M space, and the engineering faults in the basic design can be overcome. But the merits of S-100 as a hobbyist bus aren't on trial here; the simple and basic fact is that there are better industrial bus systems, and many proprietary bus designs made it out to industry, along with many more Multibus designs.

I hope this particular chassis does prove to be S-100, as it would be a fantastic find. But the odds aren't great, unfortunately.
 
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