Simple Digital Countdown Timer using 7-seg Display

I have ASM51 , because my school is still using it.

sk8boardboy

I'm not sure which program you have.
Can you give a link to a safe site to get it from,
OR
post a copy here.

Better still, switch to Keil, I'm sure a free version is available.

ExperimenterUK

sorry if my reply is too long . I give ASM51 compiler program that I downloaded .

I also use keil , but I just wear it once.

I have tried to use the keil program that you suggest and it worked when I tried it on proteus program .
but there is one warning in keil , I do not know what it means .

good news
I have found the problem and it has me finish .

whether this countdown timer circuit can be added 4 more ports for UV fluorescent lamp ? if it can how do I add it ?

good news
I have found the problem and it has me finish .

sk8boardboy

That's great

whether this countdown timer circuit can be added 4 more ports for UV fluorescent lamp ? if it can how do I add it ?

sk8boardboy

Why four ports ?
You only need one pin to turn a lamp on/off.

good news
I have found the problem and it has me finish .

sk8boardboy

That's great

whether this countdown timer circuit can be added 4 more ports for UV fluorescent lamp ? if it can how do I add it ?

sk8boardboy

Why four ports ?
You only need one pin to turn a lamp on/off.

ExperimenterUK

because in my project , I need at a UV fluorescent lamp as much as 4 to 5 .

You need to change it yourself. Try to understand the code and add code as per requirement. Start with adding one device first and then another one and so on... If you face any issue in your code post here we will help you out.