[rescue] next rescue.. Sun-1.5

Walter Belgers walter+rescue at belgers.com
Sun Apr 3 05:07:31 CDT 2016


I have made another rescue. I was tipped by a German friend about a Kontron
system on eBay. In is were old mbus Sun boards. I won the bid and collected
the system yesterday in Germany.

It is a Kontron PSI 9068 system from 1984. This is an mbus system. In it,
there are:

- Sun 501-0600 CPU board
- Sun 501-0147 memory board
- a board with Z80 stuff and RS232/RS422 (appears to be a single board Z80
system for I/O)
- a board that hooks up to an empty modem slot
- an MFM controller and ST-255 drive
- 5.25 floppy drive

The system was sold untested. The Sun boards have Kontron labels.

So, I looked at the insides first. Everything looked good and clean. I took
out the boards and tried the PSU, no problems there.

Taking a look at the CPU board, I noticed the 501-0600 indication. I found an
old field handbook on the web, which mentions these Sun-1 boards:

501-0001	256KB Sun-1 68000 CPU
501-0002 256KB Sun-1 68000 CPU TI
501-0004 256KB Sun-1 68000 CPU Kontron
501-0600 256KB Sun-1.5 68010 CPU (obsolete, unsupported)

This is quite interesting. Apparantly, there are specific Sun-1 CPU boards for
TI and Kontron. And my board is a Sun-1.5? The handbook says it has an 68010
but there is an 68000 in it. Is this some development board for an upgraded
68010 Sun-1 that was developed by Kontron, but never marketed as Sun came with
the Sun-2? This particular system was marketed as an 68000 system by Kontron,
Kontron, which is based in Munich, Germany, still exists and is still active
in the market of embedded systems).

The board looks quite similar to the 501-0001 board. There are a few more
jumpers and one TTL IC has been replaced by a small board containing an extra
Am2996PC IC.

I put in the Kontron board with the Z80 stuff (leaving the Sun stuff out) and
turned it on. This Kontron board has 2 RS232 and 1 RS422 port. The RS232 ports
are marked SIOA and SIOB, the RS422 port is marked SIOA. I could not get any
data on the serial ports.

I put in the Sun boards and gave it a try The CPU board has two connecters.
One is not used. The other splits into two RS232 ports, marked SIOE and
SIOF. I hooked up SIOE and turned the machine on. There are two LEDs on the
board, both go on briefly after turning it on. The left one went on for a
while again, then off, then on for a shorter while, off again and that was it.
At one point I have seen the other LED on as well. I started fiddling around
with the serial settings and the serial cable (with null modem boxes). I got
some gibberish so that was a good sign. At one point, using 96007E1 I got the

Using UART input.
KONTRON  PSI 9068 Monitor  (Rev C/V2.1 ) - 0x200000 bytes of memory

However, I could not enter anything. Still, this is hopeful. It shows the CPU
board is working (at least at one point) and so is memory. It also shows that
the Sun PROM has been replaced by a specific KONTRON PROM.

The pictures that the eBay seller made as well as those that I have made I
have put online at https://gallery.belgers.com/gallery/index.php?/category/7

I have been fiddling around for an hour or so now, but cannot get back a
prompt. I decided to take an old VT320 to hook up, to be sure that modem
control is working and break actually breaks. But no luck so far.


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