Amd am9512

[NeXT]

No idea how uncommon these are but apparently my Lisa has room for one as a math co-processor.
Might someone have one handy?

 

[Neon_WA]

an Intel C8231A maybe easier to get hold of

can the board take a 9511 as another alternative?

 

[NeXT]

Nobody really bothered buying the co-processor so the use of different is not documented. I honestly don't know other than this th e9512 is the chip that Apple at least offered.

 

[Neon_WA]

the Am9512 came in both 2MHz & 3MHz.. do you know which it took or both?

EDIT >> seemly the Lisa possibly took a Am9512 or a WD2001 (Western Digital made i presume) but it doesn't seem to have been supported
It looks like the Am9511 maybe a better initial alternative (cheaper & more available) and was used in other Apple systems.

 

[NeXT]

It's possible.
The only place I can see it actually being used in the spreadsheet application. Who knows how Apple programmed all seven of the programs actually made for the Lisa to use it but it does carry bragging rights.

 

[Neon_WA]

You can scrub the WD2001.. my friend just checked his data books.. its a data encryption engine :neutral:

the basic differences between the 9511 & 9512 as listed on CPU-World

AMD 9511 (AM9511) is a Floating Point Unit designed for usage with different types of microprocessors, usually as a peripheral device. The 9511 performed arithmetic and trigonometric operations with 16-bit and 32-bit fixed point numbers, and with 32-bit floating point numbers. It could also convert fixed-point number to floating point numbers and vice versa. To transfer commands and data to/from the FPU, the main processor could use either I/O or direct memory access.
Enhanced version of the FPU, AMD 9512, was released shortly after 9511. Now fully compatible with IEEE format, the AMD 9512 supported both single and double precision floating point numbers.

 

[Neon_WA]

thought you might like to read this blog article about the 9511 & 9512 by a friend of mine

http://www.cpushack.com/2010/09/23/arithmetic-processors-then-and-now/

 

[cpushack]

Sun Remarketing is who purchased much of the old Apple Lisa systems. They made many upgrade guides etc
Look here: http://www.1000bit.it/support/manuali/apple/lisa/lisaSUNREPAIR.pdf

Page 3 and page 12 both say AMD 9512

 

[NeXT]

So we now know indeed that I am looking for an AMD 9512.
I'm still not having much luck findong one myself.

 

[cpushack]

I'll keep an eye out for ya.
An Intel 8232 will also work for ya

 

[NeXT]

I'll keep my eyes out as well in hopes I come across something.

 

[jpham]

I have an AMD 9512 - not sure the condition - it is always on the black static foam
maybe I s hould put up on ebay and see who is interest in buying this chip?

 

[cpushack]

Depending on markings I could be interested.
Can you post a pic?
or email one to me?
john[AT]cpushack[DOT]com

 

[NeXT]

I would most likely be interested as well.