In desperation I tried a backup to an XLP300 SMC tape (I’d tried this before and the SMC drive made some very odd sounds). This time I used a different tape and hey-presto, the backup completed without error.
I re-installed my disk drive, inserted the SMC tape, cold-started the 8870 and the system boot loader menu appeared and I managed to recover the operating system from tape onto my drive.
The system then re-started and only complained about the memory configuration.
In the mean time, I had sent Emails to everybody I could think of and posted a question in the Nixdorf group on LinkedIn to see if anybody could remember the Niros 7.0/03 sys-admin password.
Com'on... it's been a while you know.
Somebody replied and I now have sys admin access. It's amazing how much I've forgotten.
I’ve re-configured the CORE memory size (thank heavens that SYSMOD is in English), added printer support to port #0 for my ND11 dot-matrix printer, and everything is working great. Workstation program 20 seems to support the DAP and ND11 printer ok. There is an issue with the keyboard being in German which I need to correct at some point (Z and Y key are wrong way around) and I remember that it's done with a program TPCODEUTIL... I just need to figure out how it all works again.
I’ve rebooted the system a dozen times or so over the last couple of days, and it’s clocked up around 20 hours of run-time without any problems.
The ALME had a single V24 card for port #0, and I’ve added a second one which I’ve used for a connection to a PC for very basic file transfer.
Yesterday, I spent the majority of the day translating the Manager and Expert selectors into English, and patching the MESSAGES and TF.PARAM files. My German is almost none existent so thank heavens for Google translate. It's still very slow going and my translations arn't great.
As my one and only working DAP terminal has a very slight fault (I think one of the capacitors in the HT section of the PSU is leaky as the picture keeps jumping and fading in and out slightly from time to time), I decided to also started looking at the protocol used for DAP to 8870 communication. DAP screens seem in very short supply and so if I can construct even a basic terminal emulator, that will go a long way to ensuring the continued running of the system. If I can get an emulator working, it will also allow Jim to boot his system as his DAP terminal is faulty.
I’ve also managed to make several system backups from my drive to DC600A tapes without any problems, so I’ve got operating system copies on XLP300 and DC600A tapes all over the place… you can never have too many backups.
Jim currently has my spare disk drive. My plan is to get that back, restore the operating system on that drive and make sure it's ok (that gives me two working drives), then I can risk running a format on his drive and then performing a restore.
The other thing I want to do is a CLEANUP of LU#00. If that works without any problems I suspect that will be a good indicator that the hardware is working perfectly and there are no drive errors.