[sdiy] UPD8048C question

[The Old Crow]

  Hi,

  Just having an new 8048 is not enough.  It needs to be programmed with
the correct code.  The problem is, 8048 are factory mask-ROM parts,
meaning they are manufactured with the program embedded.  End users would
submit paper-tape copies of the object code to be masked to Intel or
Nec, and they would make a minimum quantity run of chips, usually 5,000 
pieces for about $3K tooling charge and $3 per chip...$18K overall.

  There is a solution, however.  You want the user-programmable EPROM
version of the 8048, called the 8748.  It is the exact same
microcontroller except the program memory is erasable and reprogrammable.
Jameco.com in the USA has the 8748 for $14.  It needs to be programmed and
possibly erased first as it is a refurbished part meaning it was pulled
from old equipment, erased, programmed with a diagnostic, tested and
hopefully erased again.  For this you need a programming system that can 
work with the 8748/8749, and a binary file of the object code.

  I can provide the binary file.  I can even program one for you (I 
already have some 8748s), just email privately.

Crow
/**/

On Mon, 6 Sep 2004, sergio koval wrote:

> Hi all...
> 
> I´m repairing a Korg Polysix and I found that its problem it seems to be
> the 8048 micro. I put the 8048 of another Polysix and it works
> perfectly, but, when I put a new 8048 (exactly a 8048H) it doesn´t work.
> 
> I don´t know too much about microprocessors, because I only repair
> absolute analog keyboards.
> 
> Questions:
> 
> Is the 8048H an incorrect substitute for the D8048C-345 (exact number on
> Polysix chip) ? Its necessary to read some Korg memory stored in a 8048
> from another Polysix and to record it in a new one ?
> 
> Any tip will be welcome.
> 
> Thanks
> 
> Sergio