12 May
1998
12 May
'98
3:21 p.m.
R. Stricklin (kjaeros) wrote:
Hi.
I picked up a C=128 with a pair of 1571 drives and a 1902 monitor at a
thrift shop the other day. I'm a bit of a Commodore gumby---I only ever
knew one guy who had one, and it was a C=64.
I couldn't find any of the cables when I bought it. I actually did go back
this morning and found a few of them, so I have a few questions.
The 1902 monitor has 5- and 8-pin DIN connectors.
The C=128 has 5- and 8-pin DIN connectors for video, along with a DE9f for
'RGBI'.
The video cable I found has a 5-pin connection labelled 'Computer' and an
8-pin connection labelled 'Monitor'. This sounds pretty straightforward.
So my question is, which jacks are used for what? Will I not be able to
use 80 column mode with this cable? Should I wire a straight-through DIN-8
cable and use that instead of the one I have?
You need to use the RGB-I connection for 80 column on the 128. The DIN-8and
RGB-I can be connected simultaneously, output goes to the RGB port if the
40/80 locking key is engaged and the machine is in 128 or CP/M mode. In all
other cases, output is via the VIDEO out or RF out. The 5 Pin DIN you have
is probably for a C64, which uses a 5 Pin DIN for video. (The C64C shares the
DIN8 with the 128).
What do I gain by using the RGBI connector? Would one
of the Tandy RGB
monitors work with it? The thrift has one, either a CM-3 or CM-5. I forget
which.
80 column mode is about it. The output is standard CGA/EGA type. There isa
mono signal on one of the unused CGA/EGA pins (don't remember which
one off the top of my head) so you could custom wire that single pin to
a mono monitor.
Also, I was unable to locate the power supply. I
notice it has the same
connection as my A500 supply, except the switch is on the CPU instead of
the PS. Could I use the A500 supply on the C=128 until I can dig up a
C=128 (or even C=64?) supply?
The C=64 uses a DIN connector on the PS rather than the square (POST)
connector of the 128. The pins of the 128 are as follows:
1: (shield)
2: key
3: signal ground
4: +5V
5: 9VAC
6: 9VAC
The A500 power connector should NOT be connected to your 128 or
you will have a serious problem. The 500 uses +- 12V on two of the pins
so you will blow something up.
ok
r.
PS; I'm still trying to find info on that TI-99/4A video cable. (:
I have a couple of them but don't have info handy, will see if I can track.
Cheers,
Dan