8-bit binary into 7 segments - 8051-based display driver

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Joined Dec 15, 2016

I can see that this looks like what I am attempting to do with a SAP-1 that I am working on. I have purchase a 8051 microcontoller, to drive
the (3) 7 Segment displays that I want to use as an Output display.

I do not understand the programming language that you are using, but I would like to learn more about how to program this chip to display
an 8 bit binary input to a BCD output on the (3) 7 segment displays.


Joined Jun 26, 2012
Welcome to AAC!
You posted to a very old thread discussing adding instructions to a SAP-1 instructional computer. Your question is more along the lines of how to program an 8051 as a display driver for your breadboard SAP-1 so I put it here. Original thread:

Nice work by the way..

EDIT: you might consider a simple hardware solution like the ICM7218. Old chips but still available from Mouser.

For a microcontroller solution, consider a PIC instead of an 8051. Cheap to get started with and most have IO that will drive LED segments directly. Lots of PIC guys (including me) here on AAC. Since you have an 8bit databus, consider a PIC with a PSP (parallel slave port) that works like an 8 bit port in hardware. If you think you're up to that, tag this post and let us know.
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Joined Jun 26, 2012
If I read its data sheet correctly that does not do 8-bit binary to 7-segment conversion.
It will convert 4-bit hexidecimal or 4-bit BCD nibbles to 7-segment.
Technically correct but since it drives 8 digits and 8bit binary is 255 at most, the binary in this case is 4bit hex digit representations. But point taken, if the TS is looking for 8bits to 0-255 display, he'll have to roll his own. I was thinking along more conventional lines.