Hi Dave, That is an issue that needs to be re-emphasized. You can't read the EPROMS in a 7L18 without using multiple rail supplies. +5V alone won't do it.
Also, the 7L18 draws too much power for any of the 4 slot scopes. In spite of what the manual says, It is designed to operate in one frame only, the 7603. The biggest problem I found with mine was the tantalum electrolytic caps on the mother board kept failing. Also there are a pair of shottky RF diodes being used as +/- 15V power supply isolation diodes on the YIG oscillator that fail, killing the phase lock capabilities. They need to be replaced with some real diodes ;-) -Chuck Harris Dave Baxter wrote:
If no one else has said this. Check the mainframe power supplies. The 7L18 is a thirsty beast. If anyone can back up the rom images, well done. It's one of the "classic" machines internally driven by the "Original" microprocessor, the Intel 4004! The Rom's will be of a similar vintage, multi rail supplies etc I suspect. (I've only ever seen one other instrument that used a i4004 CPU, a Finnegan GC oven!)
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