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hexsane
December 20th, 2010, 02:16 AM
I need the ROM .bin/.hex files for both the CGEN and CODE so I can try to get my card working. I don't have anything that will read or write 2708s so I need both files (you must change both chips at the same time). Its badly out of sync and all I can see is a cursor blinking in 4 locations. CGEN controls sync timing so I'm taking a shot at replacing that to see if it helps.

I have a lose jump wire on the back of my card that goes from pin 3 of a 7425 (I think u21) to point unknown. Anyone else with this card have that jumper? Schematic indicates that it should go to pull up R5 but the trace has been cut and this jumper added.

-Matt

mloewen
December 20th, 2010, 06:23 AM
I need the ROM .bin/.hex files for both the CGEN and CODE so I can try to get my card working. I don't have anything that will read or write 2708s so I need both files (you must change both chips at the same time). Its badly out of sync and all I can see is a cursor blinking in 4 locations. CGEN controls sync timing so I'm taking a shot at replacing that to see if it helps.


I'll dig out my reader and give it a shot. It will take a couple of days.



I have a lose jump wire on the back of my card that goes from pin 3 of a 7425 (I think u21) to point unknown. Anyone else with this card have that jumper? Schematic indicates that it should go to pull up R5 but the trace has been cut and this jumper added.

-Matt

My VDB-8024 doesn't have a jumper on U21, or anywhere in the vicinity. The only jumper on my board is from U13.3 (an empty socket) to S-100 bus pin 52.

http://sturgeon.css.psu.edu/~mloewen/Oldtech/S100/VDB8024.jpg

monahan_z
December 20th, 2010, 12:26 PM
I have the manual up on S100Computres. There is a complete software listing there. See:-
http://s100computers.com/Hardware%20Folder/SD%20Systems/8024%20VDB/SD%20Systems%208024%20VDB.htm

I have (two) of the boards and would have to pull the EPROMS and dig up an old prom burner board to read them. If you get really stuck let me know, but would rather not. Can you just go through the listing and see if there is an error. It's a small EPROM! Pin 3 (7425, strobe) of U25 on the card is connected to +5. There should be no "jumper" was a tracer cut.

hexsane
December 20th, 2010, 02:33 PM
I have the manual. I have checked nearly every part on the board replacing only a single 2114 RAM chip. Unfortunately I don't have anything that can read a 2708 so I can't dump it to check it anyway.

-Matt