Bull Micral 45 - revival

[Lenord]

Wow, I'd almost given up hope to get that. Thank you and this guy!
It's in French but today I'll learn to read

But even with the doc I did not understand exactly how SW1-1 and SW1-2 worked.

I can explain now. Great that we've got this page, i hope we'll get the others soon.

According to that and Fred's book, i can say for sure that i have standard BM45, you have BM45 with upgrade (and someone else may have BM45V).

SIMM banks are arranged as labeled pairs: 0,1,2

In my case, first two SIMM banks (0,1) are limited to give 640k of base memory, in fact they are pre-configured for 2x256k (and 2x64k?) simms, not 2x1M. Only the last bank (2) gives extended memory, it was not an error. There were only 1Mb and 256kb SIMMs available these days, so I can choose between 512Kb and 2048k only.

Our SW1 block action differs.

I couldn't get any EMS with SW1 #1 = ON because it disables last bank (2) on my board.
That's why in this case there wasn't any activity on Z322 input connected to SIMM A9 data line (it's common for all slots, but only 1Mb simm needs that, therefore <=256Kb will be still available in each slot) and got errors when it was enabled (0/0, 0/1 combination) when last bank was unpopulated (2x1, 4x1 config).

On your board, 0-bank is always enabled, SW1 #1 = ON simply enables middle bank (1) and SW1 #2 enables last bank (2). Also, your board doesn't give error for unpopulated banks, and each bank is configured to accept 2x1Mb only (it can't auto-detect 256/1M so they've locked that to 1M and used 2 switches for better purposes, that's why you can't install any 256kb - it thinks that it's 1M). Remember, i've described same situation with 2x64k in the very first bank (0). It only counts to 128k and then hangs - so my first bank is locked to 512k like yours to 2M, only difference is that 256k is electrically closer to 64k than to 1Mb module, so I get picture and you don't get any, because significant lines for 256 are grounded.

You can't install less but maybe more? If you have any 4Mb 30-pins, you could try that in last slot, maybe that's the way to get 13Mb from the manual.
My board doesn't have proper lines for them to work, maybe yours has. Up to now, i haven't understood that 13Mb origin.

I will continue reading other pages and think more.
I hope that only Z322 PAL logics makes that difference, but we have to investigate that more, that's why i need photos of that area and maybe not only the photos.
I am going to make turbo-switch with a help of remaining switches of SW1 block, since we are sure that they're unused.

[fneck]

I placed the photos here. For the second part of the motherboard I have to drop the power supply but I don't have time to do it now. it will come soon.

https://www.system-cfg.com/files/bull%20BM45/

@ Lenord, tell me if you see enough details. The ideal would be that I remove the motherboard but I don't want to do that.

[Lenord]

@ Lenord, tell me if you see enough details. The ideal would be that I remove the motherboard but I don't want to do that.

Thank you! Photos are great. That's ok, you don't need to remove the motherboard.
And when you have time to pull out PSU, take some shots there, most mysterious place is the area around the Z322.

Up to now, I have small task in the accessible part of motherboard.
As i remember, your PC starts in turbo mode (12MHz, LED - ON).
If you have Ohm meter, please measure the resistance between 24-pin of KBC (4-th from the left) and ground when PC is turned off and voltage in turbo mode and in normal mode (after speed /- command).

Here it's:

Even if you miss, don't worry, that's harmless.

[fneck]

If you have Ohm meter, please measure the resistance between 24-pin of KBC (4-th from the left) and ground when PC is turned off and voltage in turbo mode and in normal mode (after speed /- command).

Once again you have seen right. Between pin 24 of Z815 and GND the resistance is 5.1 Kohm. And the voltage is OV at 12MHz and 5V at 8MHz. At boot I see the voltage go from 5V to 0V after a few second, before the countdown of memory and at the same time that the LED "turbo" turns on.

[Lenord]

That's what I've expected.
Then I can safely pull this pin down to ground without any extra resistance and get turbo working.
Thank you!

[fneck]

I added some pictures of the second part of the motherboard :
https://www.system-cfg.com/files/bull%20BM45/

One is missing, because she's fuzzy. I did not see it immediately and I put the power supply back
I hope she will not miss you.

[Lenord]

Thank you. It's ok. As far as i see, everything is quite similar.
If it's only Z322 what makes that major difference, I don't understand how it's affecting the capacity of my memory slots.
I've asked some friends, that's something connected with RAS signal but I don't have proper equipment to deal with signals.
This task appears to be more difficult than restoring of 12MHz.

I will write when I have some guesses to check.

[fneck]

Quelques nouveautés aujourd'hui. Une page supplémentaire de la documentation qui résume les caractéristiques de la machine :


Puis la disquette numéro 2 de Bull. Malheureusement le propriétaire de la documentation n'avait que celle-ci, donc toujours pas la disquette originale de l'OS mais tout de même une version plus récente du logiciel de configuration de la machine (version 2.2 contre 2.0d précédente).
Disponible ici: https://software.system-cfg.com/bios/bull/

[Lenord]

Quelques nouveautés aujourd'hui. Une page supplémentaire de la documentation qui résume les caractéristiques de la machine :

Thank you! This configuration with 12MHz resembles your BM45 machine more.
And this photo is better than previous. If he had some time and scanner (or camera and enough light) to take normal photos, i could arrange them in pdf manual.

pas la disquette originale de l'OS mais tout de même une version plus récente du logiciel de configuration de la machine (version 2.2 contre 2.0d précédente).

It's great that we have an updated config floppy image, i will check that later, maybe there are additional configuration options or at least new HDD types.

Up to now I've got 3xISA riser card, battery holder and 12MHz AMD CPU, used one of free switches in SW1 to enable turbo 12MHz mode.
Now looking for the FPU and some cheap flasher to test your BIOS with 12MHz CPU on my board.

I am looking for any way to allow 6Mb of extended memory like your PC has. I couldn't find any difference between our boards while looking through your photos, so maybe it's only Z322 what defines everything. Then, maybe you could check if your RAM switches are connected with Z322 in the same way. No need to disassemble PC, you could get to Z322 pins from both sides.
At least, please check any bonds between 11, 13, 14 pins and those switches (right pins are closer to SIMMs).
If they aren't connected there, they might be connected to another pins, but 13, 14, 11 are first to check.


Before you start, turn both ram switches (sw1 1,2) OFF and check the resistance(or measure the voltage) between GND and each of them (on other side of SW1, pins near the edge of PCB).

[fneck]

Sorry, for the moment I have closed my BM45 and openned a BM35 for see if the Bull's OS was on the hard drive, but the hard drive don't work actually. It's a Seagate ST-225, I hope I can read it again. I will open another topic for this BM35.

[Lenord]

Ok, no problem, if you find some time, check it later.
I've found images of Bull-Micral DOS 3.20 (FR), but these you should already have.

Concerning ST-225, its spindle could stuck after years of non-utilization.
I will think after you'll add more information about its behavior in that topic.

[fneck]

Good news, I was able to access the hard disk of my BM35 and this can boot with Bull's Ms-Dos 3.30... but bad news, all the files of the OS is not present. Nevertheless the essential is there.

With the help of an original French Dos 3.30 I have reconstructed what should be about the original floppy disks. You can find it here:
https://software.system-cfg.com/systeme/bull/

[Lenord]

[please don't repeat the previous message if it's not necessary]

Great news. So now we have 3.20, 3.30 and 6.20 variants of BM OEM DOS.
I've tested your images, everything seems intact.

New v2.2 configuration diskette doesn't take that much long with animation and seem to work generally faster.
Only problem is that 360kb or 720kb images aren't very convenient because nobody uses 360k drives/floppies.
Each time I have to correct image size before writing onto diskette.

I also got some 80287 FPUs, got ~11x gain with Intel 6MHz@12


and ~20x gain with IIT 10MHz@23? in FP operations.

[fneck]

On my BM35 I also have a coprocessor installed

The problem with the coprocessor, is that it is necessary than the software to be programmed accordingly for it to be useful.

[sytec]

hi.
I have one of these systems.

nice to see you guy's are resurrecting one, at one time there was only four known fully working examples, including my own one, most were scrapped to extract the gold, silver and platinum from the boards and chips.
it's a shame that these old systems are only worth their weight in precious metals these days, so many old systems have been destroyed and lost for all time with this.

what i have is the 3.5" 720k floppy disk with the setup/configuration files aka bios setup disk as well as having bull's version of msdos 3.2 and 3.3A and msdos 5.0
there is additional files on these disks that are for the bull micral apm45, i think i also still have the paradise drivers disc for the graphics but if i am remembering correctly it is only the dos drivers as windows 3.0 and 3.1 have their own drivers for it built in.

what i can tell you about hard drives is that the bios will only accept certain types/size's/configurations (i don't have the list of these but the list is shown in the hard drive selector inside the bios setup utility, you would be very hard pushed to get an ide drive to work with this computer as it would require not only a rather rare and very specific isa ide controller card but also an even rarer ide hdd that has the same setup/config as one of the drives in the bios list, most of the hdd's were 10Mb and 20Mb.

i did release a copy of the bios setup disk online back around 2001 to the old-computers website along with some of the information i had on the system, it was on there up until a site update around 5 years ago.

I also uploaded a lot of old software and bios setup disks and manufacturer customized operating system disks for other computers/manufacturers on vetusware.