BHolland.ElSegundo@Xerox.COM (05/27/86)
What is the GPO connection on the monitor jack for, also is there a composite color output? Thanks Bill
ralph@ee.brunel.ac.uk (Ralph Mitchell) (05/30/86)
In article <860527-100642-1332@Xerox> BHolland.ElSegundo@Xerox.COM.UUCP writes: >What is the GPO connection on the monitor jack for, also is there a >composite color output? Thanks > >Bill Looking at the circuit diagram, i can confidently state that the GPO pin is attached to pin 15 of U19. U19 is apparently a YM2149, but that may not be a manufacturers part number. U19 appears to have 2 parallel ports, 3 analog pins and a bus interface. Serial port B is connected direct to the printer (centronics) socket on the back of the keyboard unit. Port A supports GPO, RTS & DTR on the Serial socket, and has 3 lines going to the Floppy disk port for drive 0/1 select and side select. The 3 analog pins are attached to the audio in/out pins on the monitor socket. The bus interface goes to 2 6850 ACIA's and a 68901. There doesn't appear to be composite video, but then hasn't there been some discussion here recently about retro-fitting 1040's with modulator, etc. Maybe composite video appears there. The above information is probably copyright Atari Corp., but I think it's sufficiently vague that it doesn't disclose any company secrets. Besides, you could probably get the circuit diagrams direct from Atari anyway... My copies of the diagrams came with the Dev. Kit. -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ralph Mitchell | VOICE: +44 895 74000 Ext 2561 Computer Centre | ARPA: ralph%ee.brunel.ac.uk@ucl-cs.arpa Brunel University | UUCP: ...!mcvax!ukc!ee.brunel.ac.uk!ralph Uxbridge | JANET: ralph@uk.ac.brunel.ee UB8 3PH | UNITED KINGDOM | "Noli illegitemi carborundum" =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=