mu106sbn@sdcc13.UUCP (05/28/87)
I'm trying to get a Maganavox 8CM515 Analog RGB monitor to work with
an Amiga 1000. It appears to work fine, asking for Kickstart. But
after Kickstart loads, the screen goes black. The weird thing is
that if I boot all the way up using composite, it works fine. If
then, while in AmigaDOS, I plug the RGB cable in, presto! A perfect
RGB picutre. Can anybody help? I'm sure its soldered correctly...
Amiga pin # Function Maganavox 6-pin DIN #
------------------------------------------------
4 Green 1
11 H. sync 2
18 GND 3
3 Red 4
5 Blue 5
12 V. Sync 6
--
Stephen Hartford, programmer (a.k.a. student) ///
-- \\\///
Internet: mu106sbn%sdcc13@sdcsvax.ucsd.edu \///
UUCP: ...!sdcsvax!sdcc13!mu106sbn grr@cbmvax.UUCP (05/29/87)
In article <880@sdcc13.ucsd.EDU> mu106sbn@sdcc13.ucsd.edu.UUCP (Stephen Hartford) writes: > I'm trying to get a Maganavox 8CM515 Analog RGB monitor to work with > an Amiga 1000. It appears to work fine, asking for Kickstart. But > after Kickstart loads, the screen goes black. The weird thing is > that if I boot all the way up using composite, it works fine. If > then, while in AmigaDOS, I plug the RGB cable in, presto! A perfect > RGB picutre. Can anybody help? I'm sure its soldered correctly... The horizontal and vertical sync signals are not buffered (being used for both input and output) and may be a little wimpy when driving an arbitrary monitor/cable combination. If the monitor loading is too great, the system will either not work at all, or enter "genlock" mode and enable the (non- existant) external clock...phuttt. The solution is generally to buffer then sync signals with a couple of transistors in the connector shell, however some people have reported good results by simply putting 100 Ohm resistors in series with the sync lines. This is obviously a bit simpler than the transistor solution. You might try values in the range from 47 to 220 Ohms, as much depends on the monitor's input circuitry. -- George Robbins - now working for, uucp: {ihnp4|seismo|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@seismo.css.GOV Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)