EUG PD


Better Late Or Never

 
Published in EUG #33

Sorry about missing the deadline for EUG #32; it was halfway through my exams so I concentrated on book work, not keyboard work! Yes, I did pass.

Matters to tidy up from past issues:

Startup screens

Whoever submits these has a great deal of skill and patience. I'm always impressed by the opener. Keep it up!

Packed-up Disk Drive

Del Williams had a Master for the BHF which had stopped writing to disks. Well, assuming you've eliminated the drive itself (by testing different drives with known working machines), then the machine is to blame. Check for dry joints first. The only other thing I can think of is that, when the PSU blew up, it took part of the disk controller circuitry with it. On a Master this is hard to check as few chips are socketed and chip faults can be hidden by the peripheral bus controller (one of the custom 40-pin chips inside). The PBC itself could be at fault. Gosh.

Disk faults

Acorn's appendix note 019 lists the disk faults and disk fault &18 is "Sector Not Found". Their suggestion is that the disk isn't formatted.

Build it III

This EUG I've sent in a disabler design that can be used to turn on and off anything (including the mains!) without a single byte of software!

Mode 0 EDIT

This utility should have appeared on EUG #32 but my exams meant it missed the closing date. It's got a heap of assembler in it now so simple manipulation of graphics should be lots faster.

Enjoy the summer!

Robert Sprowson

The startup screen in EUG #31 was by Dominic Ford. He sent an equally impressive one for EUG #32 which I forgot about. Unfortunately reprogramming it needs his intelligence and ability so hopefully we can all see it later.

The disk problem suffered by D. Williams was more complicated. He sent me one which I disassembled using ADI. The whole first section has been deleted and intermittent sectors are also blank. There does not seem to be any physical damage to the disk itself and talking to Mr Williams revealed his other disks have suffered a similar fate.

Anyway, congratulations on passing your exams!

Gus Donnachaidh, EUG #33

Robert Sprowson