Modifying microcode

[Warner Losh]

On Sat, Jun 2, 2018 at 12:43 PM, Tony Duell via cctalk <
cctalk at classiccmp.org> wrote:

> On Sat, Jun 2, 2018 at 7:37 PM, Alan Frisbie <Flash688 at flying-disk.com>
> wrote:
> > Tony Duell <ard.p850ug1 at gmail.com> wrote:
> >
> >> > until the 8085 CFE loaded the microcode.
> >>
> >> Loaded from a TU58 cartridge, which is the main reason my 11/730 is not
> >> running at the moment. The hardware is fine, I've rebuilt the drive
> >> rollers,
> >> but as yet don't have a readable tape (not even blank, to write the
> >> microcode onto).
> >
> > I'm pretty sure that I have a complete set of 11/730 TU58 tapes in
> > my storage unit.   I might even have some brand new tapes.   If I
> > can find them, I would be happy to send them to you.   They have
> > been sitting in storage for probably 20 years, so there are no
> > guarantee that they are readable.
>
> Thanks... I will certanly give them a go. I am pretty sure the problem
> I am having is the tape, I get a low (and varying) amplitude signal at
> the output of the read amplifier, it varies with different tapes, and it's
> much the same both on the drive in the 11/730 and a standalone
> TU58 I have.
>

Given the vagaries of tape, I'm surprised nobody has made a simple TU58
emulator that can feed the proper microcode bits to the 11/730...

Then again, maybe there's no market for that.

Warner