wrote:
On Sat, 18 Jan 2014 10:15:05 -0600, Califbill
wrote:

wrote:

My first job after getting my degree, was at Itel. We were building a
channel interface to a Siemens ND2 laser printer to mimic an IBM laser
printer. I disassembled the channel diagnostics and figured out your
undocumented commands and what the response was supposed to be. Fun job.

I have been on the other side of that.
I got involved in a situation where we had 5 vendors trying to
diagnose a channel problem. The Itel AS5 guy and I were doing
microcode steps through out channel sequence (against orders) and we
were taking turns calling out the next address we wanted to stop on.
Their AS-5 microcode was lifted byte for byte from the 3158.

When we released the 4341, the microcode listing was a plant only
document. Eventually about 100 serialized copies were released to area
specialists. We had to sign a separate nondisclosure agreement for it
every year. I finally just turned mine back in because I never needed
it. We had better tools than stepping microcode.

Reverse engineered from the IBM code.
Funny story about the micro coder. His login was Floppy John. Because in
those days the Micro code was distributed on Floppy. When we left Itel
during the layoffs. They laid off 2300 of us when the AS4000 came out as
the residual lease values plumited. John went to another major company and
almost caused a shut down/ walkout by the union members as he plugged in
some equipment instead of calling the union guy to plug that wall plug in.