Seven years ago next week, Raymond Schlachter posted an offer in this
group to sell his Basicom MC-1N computer and some accessories. I have
been digging all over to find any information about this machine, as I
think I have one.

http://www.penguincentral.com/retroc...C-1N/MC-1N.jpg

Does this look familiar to anyone?

I've reverse-engineered most of the circuit, but the memory map eludes
me because it's all run by the 74S188 in the lower-right corner. I've
tried building a circuit to dump the PROM (it's only 32x8), but I'm
reading all zeros (not sensible, since the board _does_ work).

I can talk to this board via the 10-pin connector in the top-left
corner (power, serial and some I/O bits), but I can't address the
MM58174A clock chip nor the 8255 I/O chip.

I've tried the Basicom website, but they announce they are no longer
in operation.

Thanks for any light you can shed,

-ethan

Hiya!

Are you using pull up resistors on the data outputs of that PROM?
Remember the 74S188 is open collector....?

Yours, Mark.

Ethan Dicks wrote:
Seven years ago next week, Raymond Schlachter posted an offer in this
group to sell his Basicom MC-1N computer and some accessories. I have
been digging all over to find any information about this machine, as I
think I have one.

http://www.penguincentral.com/retroc...C-1N/MC-1N.jpg

Does this look familiar to anyone?

I've reverse-engineered most of the circuit, but the memory map eludes
me because it's all run by the 74S188 in the lower-right corner. I've
tried building a circuit to dump the PROM (it's only 32x8), but I'm
reading all zeros (not sensible, since the board _does_ work).

I can talk to this board via the 10-pin connector in the top-left
corner (power, serial and some I/O bits), but I can't address the
MM58174A clock chip nor the 8255 I/O chip.

I've tried the Basicom website, but they announce they are no longer
in operation.

Thanks for any light you can shed,

-ethan

"Mark (UK)" wrote in message ...
Ethan Dicks wrote:
I tried building a circuit to dump the PROM (it's only 32x8), but I'm
reading all zeros (not sensible, since the board _does_ work).

Are you using pull up resistors on the data outputs of that PROM?
Remember the 74S188 is open collector....?

Yeah... I did figure that out after I posted my initial query.

BTW, I spelled the company name wrong, it's a "Bascon MC-1N" I'm
looking for information on.

Thanks,

-ethan