access network pcs while using two connections

i have two internet connection
one is cable and other is ADSL
both are connected through router to 16 port switch
when using one connection say Cable.
i cant access pc which have ADSL connection.
is it possible to access all pcs with different connections.

i have one modem for cable connection and then SMC router to the cable connection

and a modem cum router to the ADSL connection

--cable connection------010---Modem--101----SMC Router-----|-- PC1
```````````````````````````````````````````````|-- PC2
```````````````````````````````````````````````|-- PC3
```````````````````````````````````````````````|-- PC4
--ADSL connection----010-Modem cum Router------------------ |-- PC5
`````````````````````````````````````````````Switch


if i connect pc1 to cable connection then i cant access pc2,3,4,5
which r connnected to ADSL connection.
Is there any solution for this

I agree with blue. The routers are on different subnets which will have different gateways. Computers must be on the same subnet to see each other without first going through a router.
If you only want certain computers going to the adsl line and certain ones going to the cable try this:
Turn off dhcp on both routers. Most routers will use the 192.168.x.1 address for the gateway. Set the other router to a x.x.x.2 gateway. On the computers use static ip addresses and manually assign the gateway address for the corresponding router you want to use.

I did this off the top of my head. Never done it before in real life. If you do try this please let me know if it works.