Date : Sun, 31 Jul 2005 00:01:50 +0200
From : "Dethmer Kupers" <dkupers@...>
Subject: Hello/Recognize this?
Hello folks,
just a (little) post to introduce myself.
My name is Dethmer Kupers, I'm from the Netherlands. Used an Electron from
(about) 84 till about 92 or 93, as a (great!) hobby. At school that time we
got 16 BBC B's to play with, so the posession of a 'real B' has been the
holy grail in my my life for the following years;)
Currently, my hobby (and now profession) led me to Delphi and of course the
PC-world.
I started with a normal Electron, but after adding some expansions during
the next years, a PC-case was needed. I've expanded the Electron with a
speedup from the Dutch 'Electuur' (electronics magazine) and an
expansionboard which contains a 1770 (although not working perfect, seems to
be a timing problem as far as i can remember, but is is usable), EPROMS (32K
EPROMS supported, so 1 eprom can contain two ROM-images at (for example)
position 0/1 or 2/3 etc), sideways ram, printer, serial and adc. It's a very
rare expansion, i've never seen or heard from it before. Also added a
powersupply from a PC to feed the expansion and the discdrive.
Pics: www.aqtion.nl/dethmer/electron_1.jpg till _4.jpg, 800x600. Big pics
(2592x1952): electron_1_big.jpg etc.
Picture 1: Electron from the front. The switches are used for en/disabling
the speedup and writeprotecting the Sideways RAM.
Picture 2: Top right the powersupply (wow, just cables lying around, did i
do that?). Bottom left a piece of the Electron, blue (under the
discdrive-housing) the speedup. Green PCB on top (under the drive-cable) is
the expansion.
Picture 3: The expansion. From left to right, bottom: the disc-logic. The
first 28p is the WD1770, then the DFS/ADFS in 1 EPROM (32K) appearing as ROM
0/1. Two empty EPROM slots (2/3 and 4/5). The Pres +1 replacement rom. 2x8K
Ram (6264). Decoding logic and fuse. Middle row: the ADC (gameport,
ADC0844), some logic for the printerport and the serial port (8533), jumpers
for the baudrate selection. Top row: ADC-connector, printerconnection, a
'general' expansion port (replication of the Electron Expansion port) and
the serial port.
Picture 4: Closeup of a piece of the speedup. It maps a piece of memory to a
6264 instead of the 'slow' default Electron RAM chips. For the 6264 the
Electron doesn't have to slow down. I'll remove the discdrive one of these
days and make a better picture of it.
I've also got the schematics for both expansions somewhere, if anyone is
interested i can put them under a scanner.
For years the Electron didn't do anything but collecting dust, but recently
i bought a default BBC B (no expansions at all). That was a stupid thing to
do, now I've got the Acorn-fever again;) Thats the reason i dug up the
Electron, after searching the net for BBC/Electron stuff.
I've equiped the BBC with a 1770 and two 3,5" drives now. More to follow i
hope (Sideways RAM, more ROM sockets and who knows what me and my soldering
iron can do, when time allows;)
See you around,
Dethmer.