On Thu, 28 Nov 1996, Nathan Parrish wrote:
> QUESTION #1: Suppose I got a 520. Could I install an FPU in it, and  
if
> so, how hard are the buggers to come by? (if this is a dumb question,
> please bear with -- I've been playing with dec hardware for the last  
2
> years).
> Also, "the gentleman from japan" seems to have had quite good luck
> with his 550c. However, looking on the product list at
> product.info.apple.com, I see no mention of a 550.

PB550c is a limited product which was sold only in Japan.
It has MC68040, unlike other PB500 series (LC040).

I'm not sure, but if you change MPU (daughter card) to MC68040, it may  
work like PB550c.
I don't know whether you can find the 040 card as a separated product.
(at least, there should be many "discarded" MC68040 cards somewhere in  
Japan, due to the PowerPC upgrade:-)

Another way is to complete FPU emulation on LC040, if you don't mind  
the performance.

> QUESTION #2: What gives?
> Also, I see that the internal ethernet as well as the nubus ethernet
> are either N or ? on the PB5?0's on the machine-status page. QUESTION
> #3: what has to happen for ethernet support in these guys?
> As I said, I've got 4 hours of commute time a day to kill; working on
> this type of thing seems like one of the more productive things I
> could do.

Few weeks ago, I fully disassembled my PB550c and found SONIC chip (16  
bit model) on the mainboard. (and lost my one-year guarantee ;-).
Then, I picked up if_sn.c from OpenBSD and modified it to merge the  
kernel which Mr. Hamada ("the gentleman from japan") gave me.
Consequently, it is PARTIALLY working on my PB550c. (ping, telnet, DNS,  
etc... this was my first experience of entering my PowerBook through  
network:-)

This driver is currently at early experimental stage.
Very unstable and slow.
(frankly, original if_sn.c is not a excellent code... needs some  
modifications to be a practical one. But, the most important thing ---  
where the SONIC registers are mapped --- is cleared. (how?))
I am improving it, but I don't know how long does it take... I'm not a  
specialist and have little time to do it.

---
Yanagisawa Takeshi <yanagisw@aa.ap.titech.ac.jp>

Dept. of Applied Physics, Tokyo Institute of Technology,
Oh-okayama 2-12-10, Meguro-ku, Tokyo 152, Japan