~04/1995
After looking after this column for almost two years the time has come to hand
over to 'fresh blood' in the form of Dave Walker. Thanks to everyone who's
written in over the past two years about the column.
Alan Glover
Introductions dispensed with, I'll say 'thank you' to Alan, and wish him best
of luck.
Monitors
~~~~~~~~
It is possible to connect VGA and SVGA monitors to Archimedes equipped with
RISC OS 3.1; however, only a subset of the total number of screen modes will
be available. This means that some programs which are not written to be screen
mode-independent will present an unusable display. Acorn's multiscan monitors
(the AKF50 and AKF52) can display all screen modes except Mode 23, which is
designed for use with high resolution mono monitors.
Monitors with a 15 pin VGA style connector can be connected to an older Acorn
computer's 9 pin output using a suitable adaptor available via your Acorn
dealer.
After a power-on or machine reboot, your machine performs the Power-On Self
Test (POST), which includes a complete memory and video test. Users with VGA
and SVGA monitors, or owners of pre-Archimedes 540 machines who have fitted a
VIDC Enhancer, may find that their machine fails the POST occasionally; some
monitors take several seconds to synchronise, and some VIDC enhancers may
start up with VIDC clocked at 36MHz when POST expects 24MHz. Errors generated
by this test produce a blank red screen and a "morse code" pattern blinking
out on the floppy drive light.
You can disable the VIDC check and the long RAM test by setting bit 7 of byte
188 (&BC) in CMOS RAM. This can be done with a BASIC program:
SYS 6,161,188 TO ,,A%: REM read the value
SYS 6,162,188,(A% OR 1<<7): REM write it back with bit 7 set
If you need to perform a complete machine reset (delete-power on), you will
have to run this program again to reset the relevant bit.
New Products and Upgrades
~~~~~~~~~~~~~~~~~~~~~~~~~
PocketFS version 2: £9.95
TCP/IP release 2 : £116.33 single-user
£59.95 (network version upgrade from release 1; return
original disc with order)
£39.99 (single-user version upgrade from release 1; return
original disc with order)
VLSI Floating-point coprocessor (FPA10) data sheet: £10
Prices include VAT, postage and packing. Cheques should be made payable to
"Acorn Direct".
The products are available from:
Vector Services
13 Dennington Road
Wellingborough
Northamptonshire NN8 2RL