Roaming Through The ROMs

By Derek Hilton

Originally published in EUG #11

My system comprises Electron, Plus 1, Plus 3, recently acquired double-sided drive, Citizen 224 printer, Nightingale modem (currently little used) and cartridges with PACE comms/serial link, View, Viewsheet, PMS Near Text Quality ROMs and (almost unused) Lisp.

Offhand, I could only think of a few items that I have come across in the use of these that I could contribute to any 'pool' of hints, tips and problem-solving information your group may be collecting, and you may be aware of them already. However you are free to use them.

First the PMS NTQ ROM. This needs to be unplugged or disabled if you want to use any machine code programs that occupy or use the top of PAGE &900 (And possibly start at PAGE &A00) because, without any warning in the manual, the control ROM tramples over at least &9C0/1 (sometimes!) and &09E/F repeatedly, possibly every event or IRQ?

Next View (v.E1.0) and some oddments found during use or in Bruce Smith's book on View, which are not mentioned in the official handbook.

In command mode, if the 'Bytes free' etc header has scrolled off the screen and you want to check the exact title of the file in memory, just type F (RETURN) (=FINISH from EDIT mode) and View replies:

      Editing "filename"
When using EDIT to ammend a long file, you are quite likely to have part of the last sentence in memory and the rest waiting to be read from 'oldfile'. In this case you can set Marker 1 at the start of the sentence (or anywhere convenient) and use MORE 1. Now only the text up to the marker will be read will be written to 'newfile', the rest being kept in RAM while the remaining memory is filled from 'oldfile'.

Though I don't have the details to hand, I know it's possible when using Macros to pass the number registers :A to :Z as parameters and manipulate them, both within and between calls.

Features of the later BBC View (v3.0?) not in my handbook but apparently working OK in the Electron ROM version include the stored command 'PB' which, if followed by 'OFF', turns off Page Breaks so that Headers, Footers, and their margins, plus PE/OP/EP are ignored on printout. This is very handy for labels or short pages since even with HM/TM/FM/BM set to nil, I still seem to get one blank line between pages. 'PB ON' (or 1) will restore Page Breaks later in the document if needed.

When using 'REPLACE' with Folding on, as well as N (no change) or Y (Replace, copying the case of the replaced word), you can also use 'O'. The replacing word is then used exactly as typed, as if folding was on. Thus with text:-

      TEST test Test  TEST test Test  TEST test Test
'REPLACE test Fred' and pressing N,Y,O gives respectively:
      (N) TEST test Test (Y) FRED fred Fred (O) Fred Fred Fred
Of course, replacing 'tEst' with 'Fred' is still no good, giving:
      (N) tEst (Y) fred (O) Fred"
since View only checks the rest of the word if the first letter is in upper case.

Derek Hilton
Penwortham, Preston

Some people are saying that View is now very much "old hat". Perhaps so, but it's not hard to see why it was once thought of as a minor marvel, nor why it was so expensive when first released! I don't know about you folks but even now, I am still discovering little tricks I didn't know it was capable of!

Will Watts, EUG #11