Need help. 8 bit binary to bcd conversion

Thread Starter

royashley99

Joined Nov 20, 2021
43
You can make your own using 8x32 PROMs; 8 bits would require 3 of them. If you were tempted to go that route, you should just program an EPROM with a 16 bit output. In the thread I referenced earlier, I programmed one to do 4 BCD digits.
How would I arrange the 3 EPROMs for the 3 BCD digit outputs
 

dl324

Joined Mar 30, 2015
14,480
How would I arrange the 3 EPROMs for the 3 BCD digit outputs
I said 3 PROMs. If you programmed 7488 using the table from the 74185 datasheet, it would take three of them.

Form the Nat Semi datasheet:
1637533359361.png
I think it would be less work to program a 16 bit wide EPROM like M27C4002. If you do as I did and program it for 4 BCD digits, it can be used for other projects.
 

Thread Starter

royashley99

Joined Nov 20, 2021
43
I said 3 PROMs. If you programmed 7488 using the table from the 74185 datasheet, it would take three of them.

Form the Nat Semi datasheet:
View attachment 253197
I think it would be less work to program a 16 bit wide EPROM like M27C4002. If you do as I did and program it for 4 BCD digits, it can be used for other projects.
I've never used EPROMs or PROMs so I don't know how to do that, could this work instead or should I rather use the M27C4002
 

panic mode

Joined Oct 10, 2011
2,135
you can use two 8-bit EPROMs in place of one that is 16-bit.
as mentioned before this video is going over what the EPROM is and details of using and programming one:
 

dl324

Joined Mar 30, 2015
14,480
I've never used EPROMs or PROMs so I don't know how to do that, could this work instead or should I rather use the M27C4002
You could do it either way. If you have an EPROM programmer, I think wiring will be simpler due to the pinout of M27C4002.

Since you don't have a programmer, I could program one for you if you're in the US. Otherwise, there might be a member in your area that could do it for you.
 

dl324

Joined Mar 30, 2015
14,480
I am following ben eaters video and in the parts he says to use a 74LS107 in place of 74LS76 but not sure how to connect it to do the same thing.
I don't see any flip flop in the video. Just a switch, cap, resistors, LEDs, and the chip being programmed.

1637598089949.png
1637598118538.png
The only difference I see is pinout.
 
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