binary to 7 segment problem

hi guys

i am designing a 4 bit alu with 64 bit ram and i have a problem displaying the output of the alu

it works fine with 4 leds (i only have numbers up to 15) 4 bit

i want to display the o/p on a 7segment display

so i can use 7447 or 4511 but i can only disanceplay on it numbers from 0-->9

coz its bcd so how i can cascade it to display 2 digit number (10 11 12 13 14 15)

thanks in adv

please note that i cant use eprom or pic or microprocessor

What kind of microcontroller can you use? AVR?

If you can lay your hands on a couple of TIL311 displays, that would do it. They had 4-bit inputs, latch, decoder, driver and display all together. The display was hexadecimal, so all you codes are covered.

Device is obsolete, but I saw a few sites on the net looked like they might have some left in stock.

please guys help me i need a solution to my problem

i cant find this TIL311 displays you told me about

is there any way to cascade 4511 or 7447 ic to display to two digit number

from 4 bit binary input

DM74185A - check the attached datasheet - is a 6bit binary to bcd converter.
place it between output of your ALU and bcd 2 7seg drivers

hope that helps

EDIT: you can do it with only one bcd 2 7 seg as first digit is only 0 or 1 hence you can connect the pin Y4 (MSD-A) directly to segments that make "1" on first digit and Y1-Y3 to BCD input of bcd to 7seg (A input on bcd 2 7seg is lsb from your alu) so you will get "blank" first digit for 0-9 and 1 will light for 10-15 ... clear ?

Guy on eBay is selling TIL311's for eight bucks a pop. Says he has more than 10 in stock -

**broken link removed**