Philips/needed activities

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This document describes what needs to be done to come from what we have now (hardware, backups, releases, ....) to a useable system.

Development system.

The main problem is that the original discs have disappeared. We have 2x 6875 (each 2x 2.5MB), but their status is unknown.

The drives are "naked", aka no housing, no power supply etc. However, we have an empty PTS frame, 19" and high enough. As far as can be traced, it comes from Århus, where Philips had a PTS workshop. The frame comes from an 6824, which is functionally the same as 6813, but in a more modern (yello, light brown?) frame. My hope is that the harddiscs can be mounted on slides, and the slides mounted in the frame. As one drive at a time must be able to slide out, there must be some counterweight, so the frame does not topple. Depending on the position of the power supply, this weight could be sufficient. It must be checked whether the currents and voltages supplied by the power supply, correspond with the drives needs. Dcoumentation is available.

Supposing the hardware problems are solved, we have some possibilities.

Solution 1

- make a small assembler program formatting FIX0,which is the fixed platter on drive 0

- find a backup from FIX0. This backup can easily be identified. When displaying the first segments, there should be a user SAG, and there should be a 512 byte segment containing the IPL program

- make a small program reading the backup tape image from the pc, had write it sequentially to the disc. I seem to remember that the backup program, SUM, read the disc sequentially. If that is correct, a 1 to 1 read/write should be easy to do. If this is not the case, a PC program must be written, so we can reorganize the files (in casu the segment tables), so we CAN write them sequentially.

- now format FIX1 with the appropriate DOS program

Solution 2

- very much like solution 1, with the difference that we read from the magtape. Reading and writing blocks should be easy enough, but it depends on how SUM saved the data

The programs can be developped using the Assembler and the Simulator, using simulated output files. This way we can easily check things, e.g. whether the simulated disk F0 contains the data we expect.