cmv@ihuxz.ATT.COM (Craig Votava) (02/19/88)
Here is the promised repost of the rs232 expansion board memory upgrade. I still have not done this yet, maybe sometime soon. /* Written 10:16 am Jul 29, 1987 by looney!cmv in ihlpm:unix-pc.general */ /* ---------- "Parts List for 0K RS232 Upgrade" ---------- */ Has anybody out there successfully upgraded a 0k RS232 expansion board yet? I remember hearing about some folks giving it a try, but have not heard anything yet. Well, since I've not heard anything yet, and I'm planning on doing this "real soon now", I thought I'd ask for some help from the net. After looking at the schematics for the expansion board, and compairing it to my 0K board, I came up with the following list of components that need to be added to fully populate it with memory. The only problem is that the schematic does not seem to show where all of the capacitors should be. If I could get someone to list all the capacitor's and their locations from a fully populated board, I would have a complete list of components to upgrade. As a side note, can anyone explain the multitude of capacitor locations on the board that aren't connected to anything? I thought that was kinda strange. OK, here is my INCOMPLETE and UNVERIFIED list of components needed for this upgrade. PLEASE be advised that an upgrade of this type requires many special skills to be successful, and should NOT be attempted by anyone without them. Also, anyone attempting an upgrade like this should realize that they are doing all sorts of nasty things to their warranty with AT&T and are soley responsible for any damage or problem with their system. Just to be on the safe side, insert about 10 more disclaimers here. LOCATION PART -------- ---- [A,B,C,E,H,J,K][5,6,7,8,9,10] 48256 (memory chips) 1B 74AS74 2C,2E 74LS280 2H 74F00 2J 74F32 3A 74F08 3H,3J 74F138 3K,4A,4B,4C,4E,4H,4J,4K 74F258 All Resistors are 1/4W 5% R1,R2 33 Ohm RP2,RP3,RP4,RP5,RP6,RP7,RP8,RP10,RP12 33 Ohm - 8pin Resistor Pack W1 Jumper W2 Jumper That's all I have right now, if anybody can add to the list, or offer some advice, please send me mail, or post to this newsgroup! Thanks Craig Votava AT&T Bell Labs, Naperville IL looney!cmv ihnp4!looney!cmv /* End of text from ihlpm:unix-pc.general */