5 Dec
2014
5 Dec
'14
10:26 a.m.
> I assume you're jsut going to be plugging
into the HP9830 I/O slot
Yes. I'm considering putting the mass storage ROM
on the I/O slot card
also (similarly to how the sector buffer works), but since that ROM is
hard-addressed, that won't actually free up the ROM slot it would
normally occupy.
I don't really see the point. It's fairly easy to make a ROM cartridge that takes
EPROMS (IIRC 2 EPROMs, a 74x00 and a couple of transistors (to convert
the 12V selects back to 5V). Such a board (hand wired) was shown at HPCC
a couple of years ago.
If you do make your own Mass Memory ROM module, figure out a way to
have a switch to disable it. The Mass Memory ROM intercepts all sorts of
BASIC commands, to the extent that DISP and PRINT (at least) fail unless there
is a working disk drive connected too. Continually plugging and unplugging the
ROM is hard on the connectors (yes, you can still get them, but desoldering
the old one is a pain).
Incidentally, the ROM module connector on the 9830 (but not on the smaller
machines) is 0.125" pitch, double sides, 18 pins on each side. Now where have
you seen that before :-). It made finding an extender board very easy when I
was fiddling in that area.
-tony