Hello, I’m Ketturi Fox, and I’m addict. Yes, I have VFD addiction, Vacuum Fluorescent Displays, I mean. I have big box of them, waiting for appropriate project (which probably will never come). This time I found big nice displays from old digital scale.
So I hauled my catch to home. Whole machine was far to heavy, and I couldn’t open it without allen key. Pity I can’t now power it up, because main logic, power supply and keyboard&printer are missing. Reverse engineering will also be harder.3x 6 digit ones, and one 32 digit 14 segment alphanumeric displays on each board. Small board is keyboard controller with old Intel 8-bit microcontroller. Display board both have their own processors and support logic, and all were connected together with daisy chain ribbon cable. Probably 8-bit parallel line.
Here is bottom view. From upper left there is HD63A03R MCU and ROM and couple of interface IC’s. Small IC’s are some support logic chips and 6118 VFD buffer drivers. Big missing IC is SN75518, 32 line VFD driver with internal shift register.
These black centipedes are important, I will use these for new build, and replace old processor with modern AVR. I have idea use the big alphanumeric display for showing new RSS feed and email tittles.
Modules unsoldered. I destroyed 2 of smaller displays, glassware should be handled with care. I was more carefully with big one, and managed to remove it one piece. I did not touch to other display board, for good reason :PQuick schemasketch. SN75518 6118 Datasheets for driver ICs. Now I need to make power supply, which gives about 45V grids/segs and 3V for filament.