31 Jan
2002
31 Jan
'02
2:27 a.m.
M H Stein <mhstein(a)canada.com> wrote:
Any ideas from you Apple experts how I tell CP/M
software
to use an 80 column card? Display is 40 col from motherboard,
all I get from 80 col card is a blinking cursor.
If you're using a ][ or ][+, put the card in slot 3.
There was a convention for what cards went in which slots:
#1: printer interface
#2: communications (modem/serial) interface
#3: display interface
Pascal and CP/M would probe the C[123]00H ROM spaces for these slots
to determine if there was a capable card in the slot, and if so it
would use the card for that function.
The neat thing about this was that it meant you could stick either a
parallel or serial interface in #1 depending on what kind of printer
you had, or you could stick either a serial or 80-column card in #3
-- you would use the serial card if you wanted to use Pascal or CP/M
with an external 80-column terminal.
No switches or id on 80 col card; it has 3 EPROM
sockets,
but only ROM2 & ROM3 are present. No reason why ROM1 should
have been removed, so I'm hoping it was an option.
Could be (IIRC Videx cards supported an optional character set ROM),
or it could be the ROM that would appear at C300H with the card in
slot 3. If it's the latter, CP/M won't see the card.
-Frank McConnell