How much is RAM here in router, I want to upgrade IOS
System image file is "flash:c3640-i-mz.120-7.XK1"
cisco 3640 (R4700) processor (revision 0x00) with 26624K/6144K bytes of memory.
Processor board ID 10526230
R4700 CPU at 100Mhz, Implementation 33, Rev 1.0
Channelized E1, Version 1.0.
X.25 software, Version 3.0.0.
Primary Rate ISDN software, Version 1.1.
1 FastEthernet/IEEE 802.3 interface(s)
32 Serial network interface(s)
1 Channelized E1/PRI port(s)
DRAM configuration is 64 bits wide with parity disabled.
125K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read/Write)
Configuration register is 0x3922