GE 235 System Manual page 73

Each word recorded on a disc is a replica of the word a s it appears in the GE-235 core memory.
Both binary and alphanumeric (BCD) configurations a r e retained without change.
Between 1 and 16 records (64 words each) can be read o r written with one command. Each data
disc of the MRADS unit is served by i t s own positioning arm. Each a r m contains eight read-write
heads
--
four heads for each side of the disc.
With the a r m in one position, it is possible to transfer a total of 96 records (32 on inner heads,
64 on outer heads
- -
on both sides of the disc).
Positioning Read-Write Disc-Support
Read-write heads numbered 0-7
Heads 4, 5, 6 and 7 serve the
4 heads per side
-
8
heads per disc.
outer zone of each disc.
Heads 0,
1,
2 and 3 serve the
inner zone of a disc.
MRADS POSITIONING ARM AND HEADS
The diagram below shows one surface of a disc; the division of the surface into inner zones; and
the zones into 8 and 16 sections with 128 tracks each.
Outer zone
1 record per sector
23,100
words/second transfer
rate.