The operating system is contained in the ROM IC. This is a solid state electronic storage device which has
a program permanently wired in to make the CPU work. The program is unique to the TS1000. In symbolic
form it is a long sequence of bytes. Each byte has an address showing its position in the ROM -- the
first one has addresss 0, the second has address 1, and so on up to 8191; which is why the Sinclair BASIC
is called 8K BASIC.
You can see what byte is at a given address by using the function PEEK. For example, this program prints out the first
21 bytes in the ROM (and their addresses.)
10 PRINT "ADDRESS";TAB 8;"BYTE"
20 FOR A=0 TO 20
30 PRINT A;TAB 8;PEEK A
40 NEXT A