You mean the year isn't 2001 :) -- Gareth Knight Amiga Interactive Guide- http://welcome.to/aig "Shine on your star"

OSI 527 -- 24K of 2114 static RAM OSI 470 -- Believe it or not, can be configured to do either parallel or floppy and a few other "network-like" things as well. Note that in any case, most of the board is unpopulated. If it is being used as a floppy controller, there should be a small "daughter" card hanging off of it and the cable to the floppy drive will come from that card (can't remember the OSI number for that card). The floppy may have been disconnected by removing this card, in which case there will just be a row of pins sticking out. I don't have those schematics here at work right now. I'll try to remember to bring them in tomorrow to give you more details. Assuming the serial port on the 510 is populated and enabled, then you should have a complete system with the addition of a terminal, floppy drive and system (OS-65D). If not, then you would need to add an early rev (pre-B) 540 board to give you video, keyboard and cassette. You would also need an OSI 542 keyboard. The ROMs on the 510 will be programmed to expect a certain configuration, so if the serial port is not there, filling it in will not help. Final note: What you got was a Challenger III, not to be confused with a C3 which can be a very different animal.

Should be fairly easy to find. I may have a spare, but you would have to trade me something good... It could also be built. The 510 ROMs are just the bootstrap and a very crude monitor. It should come up with some variant on the classic: D/C/W/M? prompt, you may have to hit the reset button a few times. Most probably, it will prompt: H/D/M? Press 'M'. Note! The 'M' must be UPPER CASE or the machine will ignore you. This will take you into the monitor. Once again, I don't have the reference I need, try different upper case letters followed by four digit hex addresses. PXXXX if I remember correctly will dump memory starting at address XXXX. If you get this far, the machine is in pretty good shape. Well, let's see where it is attached. There should be a 4pin and a 12pin molex connector on the top of the card, next to the corner, away from the bus. The 4 pin connector is the manual processor select, nothing should be attached there. The 12pin connector is where the serial port and reset switch should be attached. Pinouts: (Pin 1 is away from the bus) 1 -- NC 2 -- Ground (for use with reset) 3 -- Reset 4 -- NC 5 -- NC 6 -- Ground 7 -- RS-232 OUT 8 -- RS-232 IN 9 -- 20mA OUT current (probably not populated) 10 -- 20mA IN current (probably not populated) 11 -- AUX OUT (probably not populated) 12 -- -9 volts through a 470ohm resistor (probably not populated) If it is set up for 20mA current loop, then I'm not sure I can help you. My schematics don't seem to be complete for those mods. The port was factory wired for 2400 baud, no parity, 8 data bits, 2 stop bits. Only thing likely to change is the baud. Possible values are: 75, 110, 150, 300, 600, 1200, 2400, 4800, 9600 and 19.2K. If it has been changed, there will be pins soldered to the board, below the connector and the 6850 USART beneith it. Two or three of the pins will be wire-wrapped together, connecting the Rx an Tx clock inputs to a clock source. It is possible, although I can't imagine why, that the Tx and Rx clocks could be set to different rates, in which case two pairs of two pins will be connected. Not a clue. If it has a metal serial number plate then it is much newer (post-1978?) than if it has a paper serial number sticker.