Home Page Forums MAME MAME Siemens Simatic S5 PG 685

This thread neatly picks up from the Siemens PC-D one, post #102220.

The Siemens PG 685 is one of the computers that was used to program the Siemens S5 automation systems.

https://en.wikipedia.org/wiki/Simatic_S5_PLC

http://www.tecmumas.de/de/computer/siemens_pg685.htm

I've got two machines, both dead, and in different states of completion. They run on PCP/M and MS-DOS, dual boot systems were common, but they aren't IBM clones/compatibles, as the bus system is different from the ISA architecture.

I was using David Gesswein's MFM reader/emulator board to transfer the harddisk images.

Some manuals and disk images are available through

http://oldcomputers.dyndns.org/public/pub/rechner/siemens/pg685/

Machine 1 is missing the CPU card, and has a handwritten "Turbo" note on the front bezel. It might have been upgraded at some point in its lifetime as the memory cards are different from the (mostly complete) Machine 2. As it's disassembled anyway, I took the pictures of the keyboard and backplane from this one. The harddisk has sector errors when read with the MFM reader, its disk image is included for completion's sake.

PG 685 No. 1 - Backplane

PG 685 No. 1 - Bezel and Keyboard

PG 685 No. 1 - Drives and HDD controller

PG 685 No. 1 - Memory boards

PG 685 No. 1 - Harddisk image

Machine 2 is mostly complete, but doesn't work (probably) due to a fault in its power supply. The ROM image comes off this machine, the harddisk transferred without errors.

PG 685 No. 2 - Backplane and CPU/Video card

PG 685 No. 2 - Drives and HDD controller

PG 685 No. 2 - Bezel and Keyboard

PG 685 No. 2 - Memory and Module cards

PG 685 No. 2 - Harddisk image

PG 685 ROM BIOS

Got another one ...
Machine 3 actually turns on, but won't recognize the Testdisk I am writing to get it going. The testdisk is needed to set the NVRAM values for memory size, harddisk and probably other stuff.

The key switch plays a crucial role in this operation: Set it to >0<, insert the disk but leave the drive open, switch the machine on, close the drive door and set the key switch to "Normal" to load the test disk. Here I get "Disk defect" no matter what physical disk and test disk image combination I use. The disks have a 720K, 80 tracks, 9spt layout, so on a PC they have to be written in a 1.2MB HD drive onto DD media.



If I don't bother with the key and testdisk procedure and just press ENTER with the key in NORMAL setting, I get this test page:



I'm still not sure what the cause of the failure to load the test disk is ... maybe the floppy controller, as I've already tried swapping in a different drive.

The working power supply allowed me to test the set of boards from Machine 2, they work as well up to the configuration screen.

Machine 3 has a different CPU and video board from the other dumped machine, No. 2. It's using a 286 at 10MHz, so the handwritten "Turbo" note on the case of Machine 1 makes sense, it probably also had the 286 boards.
The monitor cable has headers for both types of boards.
The harddisk was dead as a dodo, swapping in another one didn't work yet.

PG 685 No. 3 - Backplane and CPU/Video card

PG 685 No. 3 - Bezel and Keyboard

PG 685 No. 3 - Drives and HDD controller

PG 685 No. 3 - Memory and Module cards

PG 685 ROM and CHAR BIOS, 286 ver.

I originally had wanted to include this site

http://oldcomputer.info/portables/pg685/index.htm

in the first post, but couldn't find it again ... turns out the guy switched providers just last week, and here it is again.

I'm guessing either the drive is bad, or the drive you are writing data to the disks for (i.e. 5.25" drive on a kryoflux or supercardpro or dos machine running teledisk/imagedisk etc) is out of alignment.

The machine had several problems: The aforementioned keyswitch was bad, after swapping the keyboards, the machine actually shows "System Reset" if I move the key to >0<.

The drives are very finicky ... haven't had it to that extent in any other machine. To get working images, I'll have to re-write the disks I made in a PG drive on the PC in the actual machine ... thankfully the Machine 2 set of boards and harddisk started booted up with some minor fuss, so I have a working PCP/M installation ... formatting a batch of disks atm.

Getting the testdisks somewhat going revealed more about the two sets of boards, e.g. their memory map:

Machine 2, 768K RAM, V20 CPU



Machine 3, 896K RAM, 286 CPU



This one also gave away that its screen buffer sits at

E0000 - EFFFFH

It can do pixel graphics using a Hitachi 46505SP graphics chip

if you have an alignment check disk, i'd check the alignment of the drives in the machine, a classic symptom of drive being out of alignment is 'it will only read disks it itself wrote or formatted'

LN

Yeah, unfortunately, no, I haven't got one of these. Would the Kryoflux reveal an out of whack drive?