I would like to answer the comments raised by Gareth Babb on my HD project:

Thanks for the reiterated warning about the flashing cursor and compacting - this would make a mess of the drive. I would also like to add that it is possible to compact the drive without using screen memory by using the full *COMPACT command:

      *COMPACT <SP> <LP>

Here, SP is the start page in Hex and LP is the length in pages in hex. For example, *COMPACT 20 40 will use memory from &2000 up to &6000, the start of screen memory in Mode 6.

The ADFS 'has to be in the highest priority socket available' because it has to service interrupts from the host adaptor which are reasonably timing dependant. Some ROMs can cause problems if they are in a higher priority socket delaying the time taken for the service calls to reach the ADFS ROM. I proved this when I was testing the system.

My little digression regarding the AP2 came about because I took the opportunity to install this software when I was installing the Electron and hard disk into the PC case. I had been using Slogger's Expansion 2 software (8K) until then and decided to give the Pres AP2 a go (I wanted the ADFS disk format command). The ROM didn't work in socket 10 but worked in all other sockets. I checked the addressing on the Plus 1 socket (10) and found it was wired for 8K EPROMS, the AP2 EPROM being a 27128 (16K) and working perfectly in my other 16K sockets, I decided to add the missing address wiring. The AP2 worked perfectly when the modification was complete. All I can suggest is my ROM isn't the same in both halves.

Gareth's article in the earlier EUG magazine was in fact the starting point in my project and I would like to thank him for giving me inspiration. I'm very pleased with my creation and have been doing my sums on the data transfer rate - approx 80KB per second. The limitation is the Electron itself as the drive is capable of transferring five times that mount of data per second but it is still pretty impressive, the entire user memory can be filled in about a quarter of a second. With transfer rates like this, a clever programmer could possibly implement "Virtual RAM" - partition a couple of mega-bytes of the hard disk to use as RAM and the possibilities for quality applications is endless...dream on.

About six months ago I decided it was time to get into the 32-Bit computing world so I looked around to see what was on offer - the choice was an Acorn, Commodore or IBM clone. I use IBM clones at work and know their shortcomings only too well so that choice was a non-starter, Acorn were far too expensive and trying to buy anything older would leave me with problems of an out of date operating system - very expensive to update (£100). Then some good news came my way, Commodore had gone bust! This meant that a large proportion of the Amiga community would jump ship and buy PCs producing a large second hand market. This is exactly what happened so I picked up a good deal on an Amiga 1200 with Hard Disk and Monitor.

Now, having had time to play with it, I feel it is far superior to any PC evn though it is only a 16-Bit front end and can't multitask (I know IBM has just introduced a multitasking OS but they are ten years too late!). A fairer comparison would be to an Archimedes but I have no experience in using one. I would be interested if anyone tell me a bit about them.

The first program I bought for the Amiga was a BBC emulator - when loaded it actually looks more like the Electron as it uses the Mode 6 character set. Anyway, it's rubbish and only simple programs run. Try anything other than PRINT on the screen and it crashes. I will keep a look out for other versions and let you know how I get on.

I'm now up to 16Mb on my Elk hard drive and have found another problem with Click - When EXTREE is used to show the tree structure of the disk it reads and stores in its own memory every directory entity on that disk. It has now become obvious that there is a memory limitation of around 128 entries. Beyond that limit and EXTREE starts to overwrite the Diary and crashes, thus making the EXTREE function useless to me because there is no way I can keep the directory entries below that number. EXTREE is also used for copying and moving files, another function now no longer available for use with the HD.

The Dircopy utility on the original ELECTRON PLUS 3 WELCOME DISK on the other hand is very useful. For example, it copies the entire EUG disk onto my HD and into any selected directory with one simple command. It not only copies files but also directories. It's also very useful if you want to make the most of the space on a floppy as you can usually get at least two issues onto one ADFS (L) disc.

Spelling. I've noticed that there are a lot of errors on each EUG and many are simple typing mistakes. For example, two characters transposed: "Editroial" instead of "Editorial". Most of these would be spotted with a simple proof-reading exercise.

When copying from tape to disk, I use two programs: Slogger's T2P3 and one from an old Acorn User cassette. I've submitted the Acorn one as I've found it copies a great deal of software, even commercial stuff. As all Acorn User 8-Bit software is now Public Domain, there should be no problem including it on a future EUG disk. It's easy to use, simply CHAIN it and follow the instructions.

Derek Walker

I apologise for my spelling and yes much could be done with proof reading. To be frank, I was rather tired when I compiled the original EUG #18. But don't you think it adds some character? Well, I'll try harder.

Gus Donnachaidh, EUG #19

Derek Walker