mfox@hpdml93.HP.COM (Martin Fox) (02/12/90)
I recently purchased a used C128D at a conveniently low price (dirt cheap). A friend has decided to upgrade to color on his IBM PC, and has an extra green-screen monochrome TTL monitor that he'll let me use. So, is there any way I can hook his TTL monitor to my C128D's RGBI port to get an 80-column display? The monitor has a nine-pin IBM-compatible plug which appears to have the same pin arrangement as my RGBI port, but plugging it in directly doesn't work worth diddly. As I can't seem to find any useful information about my RGBI port, I am having difficulty figuring out what the heck could be the matter. (And, to be able to play a game or two, I would also like to hook the monitor up to the 40-column video port. Is this asking too much?) Help! If you need more info on the monitor, ask! Martin Fox
consp24@bingsunl.cc.binghamton.edu (consp24) (02/13/90)
>So, is there any way I can hook his TTL monitor to my C128D's RGBI port to >get an 80-column display? The monitor has a nine-pin IBM-compatible plug which >appears to have the same pin arrangement as my RGBI port, but plugging it in Yes, there is a way. (In fact, when I got my Magnavox Computer Monitor 80, this had to be done to get it to work.) All you need to do is take the pin marked monochrome out of the 128 and the ground pin and hook them up to the composite video in port, ground on the outside. I have the pinouts back at my room; if you need them, just drop me a note. /-\ Monochrome -----------------| o | Ground----------------------\_/ (this assumes a RCA composite input, like stereo jacks.) Gregg W. Riedel CONSP24 @ BINGVAXA, BINGVAXU, BINGSUNS Student Consultant - State Univ. of New York at Binghamton ---------------------------------------------------------- "There are few personal problems that can't be solved by a suitable application of high explosives."
stephenc@tekgen.BV.TEK.COM (Stephen Coan) (02/14/90)
In article <15490001@hpdml93.HP.COM>, mfox@hpdml93.HP.COM (Martin Fox) writes: > I recently purchased a used C128D at a conveniently low price (dirt cheap). > A friend has decided to upgrade to color on his IBM PC, and has an > extra green-screen monochrome TTL monitor that he'll let me use. > > So, is there any way I can hook his TTL monitor to my C128D's RGBI port to > get an 80-column display? The monitor has a nine-pin IBM-compatible plug which > appears to have the same pin arrangement as my RGBI port, but plugging it in > directly doesn't work worth diddly. As I can't seem to find any useful > information about my RGBI port, I am having difficulty figuring out what the > heck could be the matter. > . . > > Martin Fox When I first attempted to get a monitor for my C128, I also had the same problem. Well, it turns out that the IBM monochrome raster scan rate is about 18.3KHz. The Commodore, to be compatible with NTSC, is at 15.7KHz. This is a difference of close to 17%. I took my C-128 to the monitor dealer and with his permission, tried a number of his different monitors on the system. Only two out of 5 he carried would sync properly to the C-128. It turns out that some of the monitors cannot change their scan rates enough to sync with NTSC. That is probably the problem you are now seeing. I ended up with an Amdek 301A monitor and it has worked fine for me. I did have to adjust the horizontal and vertical gains/size controls to get a full screen with the C-128. I hope that this helps answer this question. -- Steve Coan tektronix!tekgen!stephenc (503) 627-1794
mfox@hpdml93.HP.COM (Martin Fox) (02/14/90)
>All you need to do is take the pin marked monochrome out of the 128 and the >ground pin and hook them up to the composite video in port, ground on the >outside. I have the pinouts back at my room; if you need them, just drop >me a note. > > /-\ > Monochrome -----------------| o | > Ground----------------------\_/ (this assumes a RCA composite input, > like stereo jacks.) >Gregg W. Riedel CONSP24 @ BINGVAXA, BINGVAXU, BINGSUNS Thanks, Gregg. However, my monitor is not a composite monitor. It is a TTL monitor. It does not have an RCA composite input in the back, it has this cute nine-pine connector which has IBM-compatible pinouts. Any hints? Also, I have the pinouts, but I don't have any useful specs (like scan rates etc) for the C128D. (BTW, I just ran across a CGA RGB monitor. If you can get THAT to work on my c128D, I'd be even happier!) Martin Fox