68705P3 MCU

[rgb-man]

I have is my possession two 68705P3 MPUs. One has corrupted data in
the EPROM portion and i need to re-program it (erasing it is easy as
it has the usual 'window').

I have a modern EPROM programmer that doesn't appear to directly
support this device.

I do though have on my PC a binary of the EPROM portion of the MCU.

Is there any way I can 'fool' my EPROM programmer into programming the
EPROM side of the MCU?

The binary is only 2K in size so I would imagine that the EPROM part
is a 2716 or equivalent?


Thanks

 

[rgb-man]

I have is my possession two 68705P3 MPUs.

That should of course be MCUs.

 

[rgb-man]

I think the answer is no, but there is a very simple schematic available
somewhere that allow to connect a 68705P3 and an already programmed Eprom
(2764 or so), and the 68705P3 program itself, reading the Eprom. I'm quite
sure it was an application note from Motorola.

Interesting, thanks. I'll have a look around for the schematic you
mentioned, but if anyone knows where to find it please let me know.


Cheers

 

[Peter Bennett]

Interesting, thanks. I'll have a look around for the schematic you
mentioned, but if anyone knows where to find it please let me know.

The programmer schematic should be in Motorola's 68705 family manuals
- don't know if those would still be available on Motorola's web
site...

 

[rgb-man]

The programmer schematic should be in Motorola's 68705 family manuals
- don't know if those would still be available on Motorola's web
site...

Thanks, have looked via a search on '68705' but no result.

 

[Michael]

I have is my possession two 68705P3 MPUs. One has corrupted data in
the EPROM portion and i need to re-program it (erasing it is easy as
it has the usual 'window').

I have a modern EPROM programmer that doesn't appear to directly
support this device.

I do though have on my PC a binary of the EPROM portion of the MCU.

Is there any way I can 'fool' my EPROM programmer into programming the
EPROM side of the MCU?

The binary is only 2K in size so I would imagine that the EPROM part
is a 2716 or equivalent?

Thanks

The MC68705P3 programs itself from a ROM or EPROM when both are inserted
in a special programmer. As someone already mentioned, the schematic
for the special programmer is in the Motorola databooks. The circuit is
simple, doesn't require a lot of parts. Burning an EPROM in order to
program the uC is a pain though. I have the schematic (a rather poor
xerographic copy). I'll try to get a usable scan of it. Stay tuned.

 

[rgb-man]

The MC68705P3 programs itself from a ROM or EPROM when both are inserted
in a special programmer. As someone already mentioned, the schematic
for the special programmer is in the Motorola databooks. The circuit is
simple, doesn't require a lot of parts. Burning an EPROM in order to
program the uC is a pain though. I have the schematic (a rather poor
xerographic copy). I'll try to get a usable scan of it. Stay tuned.

That would be great, thanks.

 

[Michael]

That would be great, thanks.

Posted at alt.binaries.schematics.electronic
Good luck.

I understand the lure of making use of free parts - I do it a lot myself
- but that old NMOS chip is such a bummer to program (source -> EEPROM
-> uC) that development on it can quickly get to you. I did two
projects with the 68705 and got fed up. Moved to flash PICs, first the
16F84 and then the 16F628.

 

[rgb-man]

Posted at alt.binaries.schematics.electronic

Excellent, many thanks.