IBM System/360 2050 - Page 115

EMULATOR SERVICE AIDS
1410/7010 EMULATOR DELAYS
Figure 110 shows the selector channel delays and
adjustments for the 1410/7010 Compatibility Feature.
1410/7010 DISK CONVERSION
2302 Disk Storage Map
The following map of the 2302 Disk Storage shows
the track allocation used by the 1410/7010 Emulator:
From Through
Cylinder/ Cylinder/
Head
0-0
0-40
218-13
246-0
Head
0-39
218-11
245-45
249-45
Function
Contaim standard information
(initial program loader, volume
label, etc, )
1301 emulation area
Unused by the emulator
Altemate track area
2302 Track Correspondence
The 1410/7010 Emulator uses sequential tracks on
the 2302 Disk Storage. The location of a 2302 track
corresponding to a particular 1301/2302 track may
be determined by using the following algorithm:
(1301/2302 track address + 40) + 46
Quotient = 2302 cylinder number
Remainder = 2302 head number
Example:
1410/7010 1301/2302 track address = 1000
(1000 + 40) + 46 = 22, remainder= 28
Therefore: 2302 address is cylinder 22, head 28.
2314 Disk Storage Map
The following map of the 2314 Disk Storage shows the
track allocation used by the 1410/7010 Emulator:
114 (3/711 Model 50 FEMM
From Through
Cylinder/
Cylinder/
Head Head
Function
0-0 0-19
Contaim standard information
(initial program loader, volume
label, etc. )
1-0
198-19
1301/2302 emulation area
199-0
199-19
Unused by the emulator
200-0
202-19 Altemate track area
~ Four 2314 drives are required for each
1410/7010 access; however, only three drives are
physically used by the emulator. Drive 1 contains
1410/7010 tracks 0000-3959, drive 2 contains tracks
3960-7919, and drive 3 contains tracks 7920-9999.
Drive 4 is available for any function the user desires.
2314 Track Correspondence
The 1410/7010 Emulator uses sequential tracks
spread across three 2314 drives, omitting the first
and last cylinders on each drive. The location of a
2314 track corresponding to a particular 1301/2302
track may be determined by using the following
algorithm:
(1301/2302 track address)+ 3960
Quotient = Relative device number
Remainder = Relative track number within the
2314 device
Add 20 to the remainder (to bypass cylinder 0).
Divide this sum by 20 (number of tracks per cylinder
within a 2314 device).
Quotient = 2314 cylinder number
Remainder= 2314 head number.
Example:
1410/7010 1301/2302 track address = 1000
1000 + 3960 = 0, remainder= 1000
(1000 + 20) + 20 = 51, remainder= O
Therefore: 1410/7010 track address 1000 is located
on the first 2314 drive, cylinder 51, head O.