Small Systems Engineering, LTD Softbox Stunt Box

Anyone know what this is ? It looks like a single board Z80 computer whatever it did. It was found among Pet stuff if that is any help. Its a z80 in the center. Pic is blurry. Sorry. The outside says Softbox but, the board says "Stunt Box (c) D.Rowe 1981"

It's a CP/M that hooks to the PET IEEE-488 port.

Review here.

That is pretty much what I suspected looking at it. What could the "A" "B" mean ? Under cp/m not under cp/m ?

You could probably get a definitive answer from SSE--they're still around, apparently

I saw that after. That website is so 1995. You have to love the rotating 3d logo. It is like it came right off geocities.

Have you tried booting it? If you've got something you can plug into the serial port it might at least give you some diagnostic messages. Also, if you could get a bigger picture of the board we could tell what some of the chips are.

I wonder if that's a ST-506 hard disk interface?

I don't know if this is any better. The forum compresses the pics you upload pretty heavily. There is a z80 and 64k of ram anyway.

Yeah, still too small to see part numbers. However, at a guess I'd say the big ICs are a UART and a hard disk controller, the mid-sized ones are obviously ROMs, and I'd guess that the little ICs that aren't RAM are address-decode and clock-generation logic. Interesting.

I have a couple of Small Systems Engineering Hardbox. Those are Z80 powered devices to interface a Corvus hard disk to a Commodore PET computer, i.e. it translates the IEEE-488 to whatever interface the Corvus hard disk uses.

It appears your Softbox is a superset of the Hardbox, in that it both runs CP/M software and acts like a Corvus interface. In case you're interested, I scanned the Hardbox manual a couple of weeks ago. It is about 8 MB in size.

http://www.cbm.sfks.se/files/Hardbox_Manual_rev2.pdf

Furthermore, since the SSE boxes take a card-edge connector, either you need a custom cable with card-edge connectors in both ends, or daisy-chain two "regular" PET-IEEE cables. I found the daisy-chaining can sometimes be picky, in particular if the two cables are of different makes. Of course if you happen to own a CBM 8032-SK, you can use a single cable because that is the only PET/CBM model to use an Amphenol (?) GPIB connector. On the inside though, there is an adapter to the card edge connector on the motherboard. :-D

I heard back from SSE but, it wasn't much help. They said they don't have anything left around for these and wished me good luck. They did say they were popular devices and the sold a lot of them. There may be some hope that the software is still out there somewhere.

Fairly early Softbox

Fairly early Softbox

The Softbox, as you rightly deduce was a CP/M box which enabled you to 'run' CP/M on the Pet (really it became a dumb terminal). To boot it you will need a Pet floppy drive and a compatible boot disc.

The two 40 pin devices are 8255 PIAs. There was no hard-disc controller chip

The empty socket should have a UASART in it. I think it was an 8251. It's been some time I'm afraid.
In this version there is a small PROM in the address decode logic which flips the address map upside down after the first instruction because CP/M was intended to run on the 8080 who's reset vector was the top of memory, whereas the Z80 reset vector is location 0.

You could run it without a Pet, just using a dumb terminal connected to the RS232 port (if you had a USART). It would boot directly from a corvus hard drive too.

The Hardbox is a sub-populated version of the same hardware with different firmware which gave the Pet a hard-drive interface. A powerful addition at the time.

Other products were also formed around this hardware.

The 'JB' in the serial number alludes to John Browne (The Greatest Living Englishman) who assisted in its development.

There were later versions of this unit in neater custom-made boxes. There were also earlier examples in taller cases who's PCBs did not have the green solder-resist.
The final version, known internally as the Okey-cokey-2000 had a (I think) an 8230 serial device which supported other serial protocols.

Great insight. Thanks. I love hearing the history behind things like this and computer gear from the UK in not common here. I probably have one of the USART on something here but, I am guessing it wouldn't get me anywhere without an OS already on a HD that I also don't have. Did it have the ability to boot from a IE488 PET floppy drive directly from the serial console ? Not that that makes any difference either since I don't have the software and if I did I could just hook it to a PET.

I always find it funny that people often don't save copies of their work even after the work has become obsolete. I run into this all the time with old computer gear though. Guy spent probably spent a lot of effort on this device and they appear to have been well received. After all those hours on something I think I would preserve at least one as an example of all my efforts. Seems engineers rarely do. I guess they just move onto the next problem to solve.

I understand it as the Softbox is a CP/M computer on its own. The software you'd boot on the PET only transforms the computer into a terminal and sets it up to communicate with the Softbox. Thus if you ran the box standalone with a dumb terminal, you didn't need the PET software.

Fairly early Softbox

Fairly early Softbox

Yes. It would boot from Pet floppies. The HD was optional. The boot disk had a custom config program who's name I forget, but it was much easier to use than movecpm, or whatever the normal CP/M ute was called. I probably have a boot disk somewhere in the loft. I disposed of my Pet hardware some time ago though.

Amongst the other products made around the Softbox hardware was a computer called a Miniwini. So named because it contained a winchester HD. There were fewer than a dozen made I think. I had one until relatively recently, but a bout of 'rationalisation' saw it off.

Small Systems Engineering was a small firm in a cobbled mews in North London with a dozen or so staff. The Soft/Hardboxes were part of a product portfolio specialising in interface products, mainly for the Pet. IEEE488-RS232 (both uni and bi-directional), IEEE488-Centronics. Later a CP/M card was produced for the early IBM PC, one for the Sirius and I seem to recall there was another for a machine called an Apricot (known internally as the Prune).

SSE went on to develop some PABXs. This coincided with the deregulation of telephony here in the UK in the mid 80s. An injection of venture capital saw the company grow under a new name and become successful in that field, including a stock market floatation. It was a special firm with a good many tales of high times and high-jinks. The former staff remain friends to this day.

If happened to run across that boot floppy I would love a copy or a imgdisk image file. What hard drives would be compatible with this box ? It would make a cool little mini cp/m system if I can get it going. I suppose I better try powering it up and see if it even still works first.

Apologies for the tardy response. I've been out of town this weekend.

I'll have a snuffle about in the loft and see if I can find it. I don't have a means of making a copy, but you would be welcome to borrow it, make a copy and return it if you like ( assuming it surfaces).

One thing that concerns me however is that there appear to be a couple of unpopulated sockets in addition to that for the absent USART. I'll see what remains of my notes and see if I can deduce what they should be. I have a suspicion that they might be the DRAM address multiplexers. Were they 'LS157s? I'll see if I can help.

The hard drives they worked with were the Corvus units.

Found one

Found one

Hello again leaknoil.

I have found what appears to be my only Softbox boot disk. Let's hope it works. It is in 8050 format. I also have a circuit diagram for the box.

If you send me a message we could set something up off-board.

Redlemon said:

Hello again leaknoil.

I have found what appears to be my only Softbox boot disk. Let's hope it works. It is in 8050 format. I also have a circuit diagram for the box.

If you send me a message we could set something up off-board.

Click to expand...

I opened it up again and it looks like the two unpopulated 14 pin sockets that are labeled IC20 and IC21. The other that would fit a 8251 is labeled IC15 if that helps id anything on the diagram.

Before we go sending the boot disk on a perilous journey I should probably figure out if this can be made to work. There are three led on the front. On, A, and B. Do you remember if they will display any useful information ?

This came in a lot of gear from an ancient closed down repair shop. None of it has worked or been able to be repaired by the obvious. I had hopes for this since it is so simple and clean looking. If there are ics missing I may start to worry again. Hah

Absent ICs

Absent ICs

IC15 is indeed an 8251. IC20 is a 1489 and IC21 is a 1488. These are the RS232 drivers. No USART, no drivers required I suppose.

I think it does a RAM check and ROM checksum on boot. There should be some reassuring flickering of at least one of the LEDs. I think the 'A' and 'B' LEDs were provided because one of the products using this hardware was a bidirectional IEEE488-RS232 interface for the man who prefers big buffers. I think one would indicate 'Talk' and the other 'listen'. Later units using an external AC PSU had a single LED.

Good luck. It ran CP/M very nicely. I did a lot of good work on my Mini-Wini.

I haven't dug up the ic's yet but, I did adventure to power it on. The A and B light stay lit. The power light flashes quickly a few times and then stay lit too. That sound about right ?

Do you think if I add the serial stuff it will just realize it and use it or did't require a different boot rom ? What about all those cute rainbow colored dip switches ? What do they do ?

Redlemon said:

IC15 is indeed an 8251. IC20 is a 1489 and IC21 is a 1488. These are the RS232 drivers. No USART, no drivers required I suppose.

I think it does a RAM check and ROM checksum on boot. There should be some reassuring flickering of at least one of the LEDs. I think the 'A' and 'B' LEDs were provided because one of the products using this hardware was a bidirectional IEEE488-RS232 interface for the man who prefers big buffers. I think one would indicate 'Talk' and the other 'listen'. Later units using an external AC PSU had a single LED.

Good luck. It ran CP/M very nicely. I did a lot of good work on my Mini-Wini.

Click to expand...