ERBAUER srl - DMD135A Help Identify this 16 bit ISA Card? 386 486 motherboard...?

[Simone2013]

(was for mistake published under "software" section, sorry)

ERBAUER srl - DMD135A
Help Identify this 16 bit ISA Card? 386 486 motherboard?


Please help to identify, jumper settings, software and any useful info (ISA 8 bit friendly?) of this card. Maybe is a clone of some known board?

Thank you.

Attached Photos:

 

[KC9UDX]

Erbauer is an interesting name. It's like saying "Made by:"

"Made by: Made by:"


My best guess is it's a single board computer. You would plug it into an ISA backplane. (An Amiga 2000 would work).

 

[sergey]

It looks like a 486 SBC that has to be plugged into an ISA backplane to make a complete system. It is interesting that it uses a separate board for 486/386/387 and cache memory (perhaps they had upgradeable CPU modules?!).
My wild guess is that it is an AT compatible board, so you don't really need any special drivers for it. And yes, it will be 8-bit compatible (that is you can plug 8-bit ISA cards).

Thanks,
Sergey

 

[edfair]

Possibly an I/O processor board? Something on the order of Computone or Arnet.

 

[Simone2013]

My idea was for an accelleretor board, but it appear to be a complete system. The "daughter board" has space for the 486 (I personally installed it but was unpopulated) or a 386 & coprocessor plus cache...

I'm just curious to start it up but i don't have a backplane readly avaliable... and also the jumper are obscure...

The port should be parallel & serial 15 pin and internal connector should be IDE 40 pin, FLOPPY 34 pin, then second port COM? another (semi-broken) 26 pin? and many jumpers....
i see only a 14 MHz Crystal... not for the main processor... maybe for the serial port, clock or (!!!) video! (CGA? HERCULES?)
Where is the Crystal for the processor? where is to be installed?!?!?

 

[KC9UDX]

Except for additional expansion cards, the only thing the backplane supplies to that board is power. If you connect a power supply to the proper places on that card edge connector, you can power it up. (Be careful, of course)

 

[kb2syd]

I would suggest you do not plug this into a 16 bit slot on a standard motherboard. Backplanes are very inexpensive on the Auction Site.

 

[sergey]

i see only a 14 MHz Crystal... not for the main processor... maybe for the serial port, clock or (!!!) video! (CGA? HERCULES?)
Where is the Crystal for the processor? where is to be installed?!?!?

The 20-pin IC next the 14.31818 MHz crystal appears to be a clock generator. Possibly this one. It uses that 14.31818 MHz input clock, PLL, and VCO to generate all other clock frequencies needed by the system. These clock generators are usually programmable, so it is possible to change the CPU frequency in software (BIOS/firmware normally would do that).

All (or almost all) PC compatibles will have 14.31818 MHz crystal. Even newest Intel Core i7 computers have it... That was the only crystal installed in the original IBM PC (and XT), and it used to time all the components of system:
- Divided by 3 to generate the CPU and DMA clock (4.77MHz)
- Divided by 6 to generate the clock for 8253 timer (used for time keeping, memory refresh, and sound generation)
- Present on ISA bus (OSC signal), which is:
- Used for CGA timing
- Used by sound cards (e.g. Adlib)

 

[Simone2013]

Ok, Thank you all. Now I understand in full... Maybe setup is accessible by BIOS... A motherboard manual is impossible to find!!!
I'll go For a backplane, Then...