17 Apr
2008
17 Apr
'08
5:46 a.m.
Enjoy the mahcine. It's one of my favourite 68K boxes. I have a 256K RAM
card in one slot of mine, and a GPIO (16 it parallel) interface in the
other. RS232 and GPIB are of course built-in.
How much memory do you have on the provessor board? Most came with 256K
(all loctaions filled with 4164s). You can increase it to 1M by replacing
all the RAMs with 41256s, fitting a 74F158 in the spare location at one
side of hte PCB, fitting a 33 Ohm (I think originally 31.6 Ohm, but it
makes no difference) resistor in the ovious positon, and cutting a couple
of jumpers (I can look up details). I've done this to my machine.
And which keyoard do you have? The 'compact' keyoard is odd in that it's
not scanned. One side of each switch is grounded, the other sides feed
banks of 4051 multiplexers.
-tony
It's a 256kB processorboard, but I have a 2M Ram board with it.
I also have a 'secondary processorboard' with a 68020 and 68882 at 25Mhz
with 4M on it from Newport Digital.
I got the small keyboard and have to share it with my 220 so if somebody has
a spare I'm in for it.
I like the machine also because it's a very compact design, and takes not
much deskspace.
Rik