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Intertec Superbrain hard disk

Roland Huisman

Veteran Member
Joined
Mar 24, 2011
Messages
1,464
Location
The Netherlands
Hello Everyone,

I've got a car full of fun for a couple of beers. Namely 2,5 Superbrain.

01 machines.jpg

One model has two single-sided floppy drives. The other one
has a double-sided floppy and a Ampex Pyxis 13 10MB hard drive.
And is turns on as well...

02 boot choice.JPG

And the hard disk model even boots! But it seems the disk has several
corrupt files and probably some bad sectors. So I would like to try
an other hard disk first to install CP/M.

03 boot cpm.jpg

Let's find the hard disk controller. It is well hidden underneath the monitor.

04 back.jpg
 
On the internet I could not find a machine that has a hard disk installed.
The only information I could find is about a disk called compustar.
Does anyone recognise the additional hardware? The previous owner
build it in by himself. Probably it is the compustar hardware.
But I can't see compustar on the PCB's. Only the name ACT.

05 hidden controller.jpg
06 Controller board.jpg
07 adressing.jpg

It has also a special ROM version...

08 eprom.jpg

I wonder, is there any software for this hard disk controller
to install a fresh CP/M on an other hard disk?
Does anyone know where I can find that software?

Thanks in advance!

Regards, Roland
 
Hello Chuckster_in_Jax,

I know the nerwerkversion is called the Compustar.
But... It seems a harddrive option was also called the compustar.
A bit confusing...

You can see an external drive here:

81ad.jpg

Regards, Roland
 
Roland,

It seems you might have the same Superbrain version as I do (see here). The built-in MFM hard drive apparently was not a standard Intertec option, and I've been looking for its origins since I got the machine second-hand in 1989. It was quite mysterious.

Judging from your name and from your recent (very cool) Holborn restauration project, you're Dutch too so that all fits the picture. By chance, I got in touch with the gentleman who actually developed the hard disk version a few months ago. Turns out the hard disk was an upgrade done by Dutch firm Rodelco in Rijswijk. Full documentation still exists. I should be polite and check with him first, but I'm sure he can help you along. Maybe send me a PM with your email address?

Cheers,

Oscar.
 
Hello Oscar,

I'm dutch indeed. I picked up the machines in Amsterdam.
The man called the compustar harddisk by name.
I really wonder if it's a clone...

The pcb's are quite nice. Not one modification. So well designed.

I really like to get in contact with the dutch designer.
I've sent you a pm.

Regards Roland
 
Hi Guys and Girls

O yes, I do recognise those machines. Not that one specific but generic. The machines shown by Roland are not assembled/modified by me, as I didn't use those powersupplies, and I didn't mount the HD controller beneath the monitor.
Lets give some comments on the pictures.
1st, yes that's a car boot. (Hmmm the sticker on the SB... think I have seen that one before... I'm in doubt now)
2nd; Again a boot, but than shown as option on the screen (I wonder whether that one wobbles, due to screen controllerchip set at 60hz by default).
3rd: Looks like the machine was used for Dbase classroom. (can you also access a second partition, if available? Maybe there's the software deployed where you're looking for)
4th: The back site, with extra PWR supply mounted behind floppy and HD (some metal was removed to give space to the HD), and controller hided beneath monitor
5,6 : The ACT controller with connectors for 2 HD's.
7th: The IO addressing board between SB and ACT controller, probably set to IO 0C hex. (The SB has all relevant data- address- read- write- i/o select lines etc routed to a connector at the back of the board.
8th: The SB bootprom, with a mod to read 1st sector of HD instead of 1st sector from the floppy.(selectable)

Intertec Superbrain was available in several flavours during it's existence. Standalone with floppies was the default.
Compustar is also an Intertec machine. The base is a more or less stripped Superbrain. They were available with or without floppies.
The diskless machines did boot from the networkdrive with a special bootprom installed in the SB.
The Compustar network was an parallel bus network, with 2 (wrist)thick cables to the machine (twice a DB25 connector), a daisy chain network. The largest disk was a Control-Data 96MB enclosure. 80MB solid, and 16MB removable platter. The Compustar "cluster-controller" was a separate box connected between network and diskunit.
As far as I know Compustar "network" was installed at 3 locations in NL.

During those days there were several suppliers who had external storage manufactured for the SB. The one I know, and worked closely together with, was Corvus ( Hey "Modesto M.. 3rd", might you ever read this; I still have good memories on working together and our endless Pizza conversations in Munich and the Sil Valley! (btw, is there a M.. 4th by now?) ). They could deliver external storage (5MB~20MB with a stack of 4 drives it could be expanded to 80MB max.) for Apple, Xerox, Osborne etc etc. They were even able to share the HD between the different opsys machines by the use of an mux connected to the HD enclosure. The "network" was flatcable based. Max range approx 40mtrs per machine. Once came the occassion that the distance was not enough, so I developed a small amplifier box to extend to 3 times the normal length with the use of 2 boxes.
Here's a pic of the 5MB Corvus I still have. It sounds like a boeing 747 at start up,
(hmm, upload doesn't work. I will try later in another post)

Corvus later on delevoped the Omninet. A 2 wire twisted pair network, speed 1mb/s, max distance (i'm not sure) 120mtr, 150 Ohm terminated. It was not available for SB, but was merely introduced as THE network for IBM-PC and Apple's back in the good old 80's. Also in those Corvus days: Interfaces (Omninet transporters) for IBM ISA, IBM Microchannel, Apple.The Corvus Concept (a propietary system. beautiful A4 computer, booted from external HD (flatcable or Omninet) or from ~10 floppies), The Concept has also been available as Unix workstation. The Mirror (a VHS recorder used as backup system. (make sure it was set to black/white recording)), The Bank (a ~250MB 100 track endless tape omninet backup system), CMux (flatcable multiplexer), CPS (Corvus Print server. A beautiful small box serving 3 printers. 1 par, 2 serial. Bit difficult to setup. But once operational: A charm). Omninet drives: 5 1/4"" from 5Mb to 128MB. More Omnidrives could fit in the same network.
A bit more info on: http://www.corvusmuseum.com/
I still have the Constellation software for Apple and for IBM.
I recall Corvus never reached the "real" commercial ethernet era, it went broke.... Or?

Back to the Superbrain.
The Superbrain was sold all over the world.
We merely served the NL and Belgium market, with extra in depth knowhow as a selling tool. Such as modifying the opsys for Azerty keyboard, HD modifications. Corvus setup. Extensive Compustar knowledge. In house repairs for mainboard, video, power, floppy etc etc.
Static discharge was one of the most common things, which were the reason the machine "hangs". Mostly shown with flashing random characters at the screeen. It was very sensitive. We even tried to spray the inside cabinet with electrical conduct material, and have it connectwed to ground. It worked...... more or less. Another issue was the head-load at CDC or spinup at Tandon floppy drives. Exchanging floppies from one to another machine could also give "bad sector" messages. Good head alignment was essential (done with special cats-eye floppy). Somewhere in my brain is a file which tells me about a mod to the flop controller and the bootprom to allow for a delay before accessing the data...

To make this post come to an end
There is still software available for the SB. I have a huge collection of SW and documentation.
A few months ago I wanted to get rid of all the stuff I have on the attick. I do not need all that old stuff anymore. If I want to see something old I look in the mirror.
So I posted the SB with all Hw and SW belongings up for auction at Marktplaats.
Oscar showed to be a really serious collector, so we made a nice deal.
While re-assembling the SB something went wrong. I shortcircuited the powersupply +12V to gnd. Dead!
Also the Rodime 6MB HD was noisy (NOISY). A friend has taken care of that in his clean-room. Sounds like new again.
Taking the SB apart again and doing some measurements there were a few parts blown in. Replacing a zener, opto-coupler and a scr made the SB work again.
Doing some tests the memory appeared to have some problems. Small programs runs fine, larger won't load. I expect something is wrong in Ras/Cas.
I will have it back on the bench later, as now we have family from abroad and summer holidays are coming.
Hooking up Saleae logic analyzer will show where to go from there. Anyway I have done tracing many many times in all kind of HW, so it will be solved eventually.

That's it for now.
I will try to load some pics in a next post.

Ton Hekstra
"AND-0FH" Hard/Software Solutions
 

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P1030619.jpg
Corvus 5MB


P1030607.jpg
Cis Cobol: Sealed in original wrapping.


P1030622.jpg
Spare Control Data floppy drive (with original Intertec sticker)


P1030603.jpg
In Depth documentation. Created by Stagiaire (Hey Paul, aka "Palletje", yes this is yours !)


P1030604.jpg
Original Superbrain Users Manual (extended version)
 
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Hello TonHek,

Thanks for your comprehensive reply! Very nice historical information.

It seems to be the same PCB as you have in your machine. The man who gave me
these machines told me that the HD controller PCB was mounted at the place near the floppy.
(Like your machine) But when I opened it it looked different. Well hidden underneath the CRT.
He also told me that he build it in by himself.

About the PCB for the hard disk. I'm very curious, where did it come from?
Who designed it? Did you design it?

I really like to have documentation about these PCB's. And I would to know
how to setup the drive from scratch to install CP/M. The hard disk seems to have
some problems. It has read errors, repeatedly searching for data. And sometimes
it spins down out of the blue... Turn off and on the computer and it runs again.

Are the disk settings fixed in eprom? Or are there settings made on track 0 from the HD?

And were there also modifications made on the motherboard for the hard disk extension?

Oh this is the B: drive.

B partition.jpg

Many thanks for your information!

Regards, Roland
 
Hi Roland.

Just a quick one.

Have you tried stat *.* on both partions to reveal hidden files?
Look at the file 64QBS5/5.ASM. (type b:64QBS5/5.ASM and hold~continue screenoutput with cntrl s)
The 5/5 in the name COULD be a hint to the current setup 2 partitions, 10MB disk, each partition 5MB.. right?

No, the controller is not designed by me, I'm not that smart. The ACT controller was made in the US (I do not have schematics). The original ASM software by Michael Hopper (ACT). I just made some mods to the ASM (finetuning, extra features, and also adapted for SBII)
The Source (with mods) supports up to 2 disks, size of the disks defined as with: nr heads, nr tracks, sector size (if i remember correct) with "free" partition size settings (1 or 2 partitions per disk) , also buffered or non buffered step.

No modifications on SB mainboard needed to install ACT HD controller. (but might you want to boot from HD, another Eprom should be fitted (you already have that one))
Looks like you have a faulty HD, check whether it gets 12V correct. Some molex do connect like sh*t.

Regards, Ton
 
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Hello TonHek,

I'm back from holiday's.... Thanks for your answer!

Is it possible to get this software to setup a new file system on another hard disk?
Can you make me some copy's on 5.25 disks of make some images for me?

Regards, Roland
 
Hi Roland

Have you done as proposed in my previous answer? You probably have the needed on the HD yourself.
No, I can't make copy as I don't have hard/software right now to do so, and as you can understand I will not ship originals to you for duplication.

Regards, Ton
 
A little update... But still enough questions...

In the meanwhile I've got the software from the previous owner.
It's quite a lot! There are even original CP/M disks. On these files is also
the 6qcpm5/5.com file. When I run this file it seems to be a Sysgen variant.

I've made copies of the files on the hard disk. First I had about 20 unreadable files on the B drive.
But somehow, after an hour running and 3 -out of the blue- HD spindowns, it could read
most of the files. Only 2 files can't be read due bad sectors. (I still have to look for hidden files btw)

When I boot from a standard CP/M disk, the hard disk is not known (off course). A: is floppy 1 / B: is floppy 2.

When booting from harddisk, A: is partition 1 / B: is partition 2 / C: is floppy 1 / D: is floppy 2 (if present).

When I make a bootdisk from the harddisk bootsector, the system starts.
(sysgen: source is HD target floppy) When booting from this diskette CP/M jumps
to A: which is the hard disk at that moment. Also the B: partition is accessible.
But it is not possible to access the floppy drives any more.

This behaviour seems to be logical. When I boot from the same floppy with a
'new' hard disk attached, the system hangs. But the LED light up from the HD.
So it does see the hard disk, but there is no information on it and it hangs.

As I see it now there should be a bootdisk which supports the hard disk.
There should also be a special formatting program. Because the standard
SuperBrain format can only format a B: floppy.

So I thought maybe the 6qcpm5/5.com file could make a boot disk which
could see the hard disk. But unfortunately it doesn't...

Any ideas?

Regards, Roland
 
Hi Roland, and others.

Just let me explain the Superbrain bootprocess.
The bootrom on the mainboard, depending on your choice, reads the first sector of the disk, head 0, track 0 (floppy or HD). The content of the bootsector itself is not that much different for floppy or HD. The main difference is whether to load opsys, just an amount of sectors, from floppy or HD. The big difference is what's in those sectors. So, when you got sysgen from HD bootsectot and put in on the floppy, the next boot from floppy tries to read the opsys, the amount of sectors which contains CP/M and jumps to 0000H, from HD.
To create a working CP/M with a HD in the Superbrain from scratch you need:
Create a working bootdisk which has the modified CP/M ASM file linked-in, that ASM file has BDOS and BIOS modified with all HD parameters and I/O, where the floppy is assigned the A: drive in the ASM file.
The output will be a sysgen file which you execute and write to the first floppy (btw, that's only option because the HD is not recognised yet)
Next is to regenerate the same sysgen file, modify the ASM so that the HD is A: (and maybe a second partitions as you prefer).
The output will again be a sysgen file which you execute, but this time the HD is your target. Be sure that you've booted from the floppy where the HD is already present in the opsys.
You need to have the original CP/M sysgen file (floppy only), the HD BIOS BDOS ASM file, ASM assembler, Linker, DDT and an editor.
To format the HD, as I recall, there should be a file something like "R6DTEST.COM"
The format program is stand alone, you do not need to have CP/M linked already to recognise the HD.
The R6DTEST accepts parameters which I/O address the controller has etc etc. It's a user friendly programm :)
An issue might be the HD itself whether it accepts buffered step or not, as I have bad experience with drives which didn't accept buffered step.

That's all.
Prerequisite is the posession of the files mentioned.

Regards, TonHek
 
Hi Roland, and others.

Just let me explain the Superbrain bootprocess.
The bootrom on the mainboard, depending on your choice, reads the first sector of the disk, head 0, track 0 (floppy or HD). The content of the bootsector itself is not that much different for floppy or HD. The main difference is whether to load opsys, just an amount of sectors, from floppy or HD. The big difference is what's in those sectors. So, when you got sysgen from HD bootsectot and put in on the floppy, the next boot from floppy tries to read the opsys, the amount of sectors which contains CP/M and jumps to 0000H, from HD.
To create a working CP/M with a HD in the Superbrain from scratch you need:
Create a working bootdisk which has the modified CP/M ASM file linked-in, that ASM file has BDOS and BIOS modified with all HD parameters and I/O, where the floppy is assigned the A: drive in the ASM file.
The output will be a sysgen file which you execute and write to the first floppy (btw, that's only option because the HD is not recognised yet)
Next is to regenerate the same sysgen file, modify the ASM so that the HD is A: (and maybe a second partitions as you prefer).
The output will again be a sysgen file which you execute, but this time the HD is your target. Be sure that you've booted from the floppy where the HD is already present in the opsys.
You need to have the original CP/M sysgen file (floppy only), the HD BIOS BDOS ASM file, ASM assembler, Linker, DDT and an editor.
To format the HD, as I recall, there should be a file something like "R6DTEST.COM"
The format program is stand alone, you do not need to have CP/M linked already to recognise the HD.
The R6DTEST accepts parameters which I/O address the controller has etc etc. It's a user friendly programm :)
An issue might be the HD itself whether it accepts buffered step or not, as I have bad experience with drives which didn't accept buffered step.

That's all.
Prerequisite is the posession of the files mentioned.

Regards, TonHek
 
Hi Roland, and others

Regarding sudden "deadth". Check the 5V. It is very critical.
The SB needs to have 5.00 ~ 5.05 at the memory bank.
It can be adjusted by the white pot at the powersupply board.
Be carefull, it's sensative.

Regards, TonHek
 
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