Bull Micral 45 - revival

Pour tout ce qui touche au PC d'IBM et ses nombreux descendants. Attention tout de même, au delà de quelques MHz la discussion devient vite hors sujet.

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Re: Bull Micral 45 - revival

Message par fneck » 04 avr. 2019 21:07

I just checked the EPROMs that I had flashed, they are not good. There is only 16KB of writing on the 32KB of the file. I do not know why. I was going to try again.
Lenord a écrit :
04 avr. 2019 19:48
I've also provided 2 files (ODD, EVEN)
Can you give me your files please?

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Re: Bull Micral 45 - revival

Message par Lenord » 04 avr. 2019 21:16

I just checked the EPROMs that I had flashed, they are not good. There is only 16KB of writing on the 32KB of the file.
Strange thing. Have you checked that they are totally UV-erased before writing?

Here they are: Full BIOS, ODD and EVEN parts.
https://drive.google.com/open?id=1hv63T ... 36B0LjMbHA

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Re: Bull Micral 45 - revival

Message par fneck » 04 avr. 2019 21:53

OK thanks 8)

It's better now 8)

Image

It is a problem of use of my flashing software which made that I had error with the preceding one (I still not have understood why... but it is another problem :roll: ).

So it works well from what I saw. The only visible difference is that the computer starts at 8 MHz but I can switch it to 12 MHz with the SPEED command. I quickly did some tests, including a memory test, everything seems correct.

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Re: Bull Micral 45 - revival

Message par fneck » 04 avr. 2019 22:03

However, concerning the files, it seems to me that you have reversed even and odd. But I'd have to check, anyway, I've swapped them.
But I'm sure of nothing, It may be me who reversed in what I posted above :(

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Re: Bull Micral 45 - revival

Message par Lenord » 04 avr. 2019 22:13

fneck a écrit :
04 avr. 2019 21:53
So it works well from what I saw. The only visible difference is that the computer starts at 8 MHz but I can switch it to 12 MHz with the SPEED command. I quickly did some tests, including a memory test, everything seems correct.
Nice work!
3072k too...well, now i can assure myself that strange memory recognitionisn't caused by old ROM...
So, I have to get 12MHz CPU somewhere and check that.
Turbo LED is not active by default? It becomes active after SPEED /+ command?

By the way, have you tested other combinations of SW1 switches?
It seems that we have just 2 switches for RAM configuration - №1 and №2.
As i remember, you've just tried to turn off №1 and it limited all your memory to 640+1024k. I got 640+512k with that.
Excepting yours, we have 2 more combinations - ALL ON(640+0k) and mine (1-OFF, 2-ON) giving me 640+2048k.

If you have more SIMMs, try to install 6x and test again. I will think about the results.
fneck a écrit :
04 avr. 2019 22:03
However, concerning the files, it seems to me that you have reversed even and odd. But I'd have to check, anyway, I've swapped them.
But I'm sure of nothing, It may be me who reversed in what I posted above :(
Maybe, it was done via BIOSUTIL.
Modifié en dernier par Lenord le 04 avr. 2019 22:23, modifié 2 fois.

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Re: Bull Micral 45 - revival

Message par fneck » 04 avr. 2019 22:19

No, I did not try anything else. I'm waiting to see if we can get the documentation.
Lenord a écrit :
04 avr. 2019 22:13
Turbo LED is not active by default? It becomes active after SPEED /+ command?
Yes, that's right

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Re: Bull Micral 45 - revival

Message par Lenord » 04 avr. 2019 22:27

Ok, then at least my problems with turbo might be fixed by proper 12MHz CPU. Maybe i have BM45 "green" edition :lol:
Thank you much for testing my BIOS.

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Re: Bull Micral 45 - revival

Message par fneck » 06 avr. 2019 09:23

I do not think that replacing the CPU will change anything. At that time, unlike today, the CPU speed is not detected by the motherboard. It is the division of the oscillator that defines the frequency, either without possibility of change, or with jumpers / switches or by software like SPEED (or the BIOS) in our case.

fneck a écrit :
04 avr. 2019 22:03
However, concerning the files, it seems to me that you have reversed even and odd. But I'd have to check, anyway, I've swapped them.
But I'm sure of nothing, It may be me who reversed in what I posted above :(
Finally after verification, it is I who reversed even and odd on the labels of my Eprom. I have difficulties with this notion.
Sorry, I'll have to fix that 8)

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Re: Bull Micral 45 - revival

Message par Lenord » 07 avr. 2019 15:49

I do not think that replacing the CPU will change anything. At that time, unlike today, the CPU speed is not detected by the motherboard. It is the division of the oscillator that defines the frequency, either without possibility of change, or with jumpers / switches or by software like SPEED (or the BIOS) in our case.
Yes, I also think so but then my CPU should work overclocked, i.e. at 12MHz, not 8MHz.
I have same 48MHz oscillator, same settings and even speed /+ command doesn't make any sense.
There might be hardware switch for divisor but I couldn't find that.
Finally after verification, it is I who reversed even and odd on the labels of my Eprom.
Nice) Then BIOSUTIL works correctly and my BIOS functions well.

Made minor corrections in my previous configuration.
Image
I've found that port 15 line of Intel 8742 KBC was typically used for specifying its (internal bios?) type (AWARD/PHOENIX)
Lots of motherboards had that. For example,
http://toastytech.com/manuals/Magitroni ... Manual.pdf
So we could assume that J1 was for Phoenix type and up to now we've known the purpose of each jumper.

Concerning SW1 block, №4 seem to act close to J1 and all №3,6,7,8 seem to be completely unused.
First pair of the remaining three switches is for RAM configuration (№1,2) and the last (№5) enables onboard video.

Nevertheless, at SW2 block we still have 3 unknown switches, grounding 3 inputs of Z904 (PAL20L8ACNS).
I've spent a lot of time and recovered their circuitry.
Image
Since that logic is pre-programmed (same for all chips with stickers), I can't determine its links. :cry: I can just say that it's connected with control lines of onboard device chips (Floppy, Serial/Parallel, SCSI, Mouse controller) but also data lines going from/to ISA bus (via buffers).

Voltage measurements (after full bootup) show that №1,№5 (or together) don't change voltage of any Z904 line (except themselves), only №4 changes 4.18 to 3.6V at I/O2 (16) line. This line is CS2 signal of Printer port in ZA61 controller.

Since my "turbo" light always disabled, I can't check if they influence on that.
Same for RAM switches.

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Re: Bull Micral 45 - revival

Message par fneck » 08 avr. 2019 09:32

Today, I do not really understand, how fast is your processor running now? 8 MHz is that right?
And when you use "speed" it changes or not (not on the LED but with software)?

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Re: Bull Micral 45 - revival

Message par Lenord » 08 avr. 2019 09:41

Yes, it's always 8MHz and speed /+ command doesn't change this (and doesn't turn Turbo LED on either)
As far as i know, that oscillator and internal divisor are the only things determining CPU speed.
Maybe internal divisor is locked in this CPU or motherboard blocks that.

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Re: Bull Micral 45 - revival

Message par fneck » 08 avr. 2019 09:58

Yes, it's strange. It actually looks like you have a version of BM45 fixed at 8 MHz.
While all I could find and read on this computer indicates that it was at 12 MHz.

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Re: Bull Micral 45 - revival

Message par Lenord » 10 avr. 2019 18:53

Yes. And that strange memory issues...
I hope something changes when i install another CPU :?

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Re: Bull Micral 45 - revival

Message par fneck » 15 avr. 2019 21:38

fneck a écrit :
31 mars 2019 19:05
I had an answer to the email sent to the owner of the documentaion quoted above. It is not absolutely certain to still have the manual but he promised to check. But it will not be for now, we must give him some time to find...
Some news today. Unfortunately the contact for the documentation has not yet found it. It still has cardboard to explore but in the end it is not sure to have it yet ... To be continued.

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Re: Bull Micral 45 - revival

Message par Lenord » 15 avr. 2019 23:41

(...)
Good news, at least he hasn't forgotten about it. I hope he finds that finally :)
I am still looking for proper CPU and ISA riser.

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