IBM 7090 User Manual

1
ACC overflOW,~r ~Q OV. MQ Overflow or
Underflow Bit In Underflow
ACC "P" Tgr On
2.03.36.1 2.10.51.1
~-----------~~~~----------~
Prevent
SB-PR
17 (D2)
( 2.11.40.1
Prevent
Decoding
Instruction
Prevent
AD(3-17)-
AS 19 (D3)
2.10.09.1
I
PC---AS
EO (D3)
MF Store
Control
3.05.09.1
2.09.00.1
AS--SR (21-35)
E2 (Dl)
3.06.12.1
SR -SB
E4 (D3)
2.09.00.1
..,
Prevent
---AS 16
El0 (D2)
3.06.14.1
•
AS-AR
Ell (Dl)
3.06.18.1
'f
1
Prevent
SB-SR
E7 (Dl)
2.12.50.1
'¥
I-AS 14
El0 (D2)
3.06.14.1
T
Prevent
PC-AS
E9 (D3)
3.05.09.1
..
AR-PC
13 (Dl)
3.06.05.1
Ten in PC
Prevent
PC Adv
19 (Dl)
2.11.51.1
"E" Time
,
Turn On FP
Trap Tgr
14 (D3)
2.10.51.1
Force Str
17 (Dl)
2.11.40.1
AS--AR
111 (Dl)
3.06.18.1
MF Store
Decrement
Zero in AR
"I" Cycle Following
Floating
Point Operation
Prevent
Channel Trap
16 (Dl)
2.10.56.1
Prevent
Interrupt
15 (Dl)
2.10.60.1
MF Store
Address
2.09.01.1
2.,o~~~~'
Y"Y.yy
Spi II r ---L---er-.I..- r
Identification t , , ,
Trap to Ten
f
Reset MQ
DV Tgr
11 (Dl)
2.10.51.1
I-SB 14
E Time
I-SB 15
E Time
2.10.50.1 ') 2.10.50.1 )
Condition Occurred Overflow in ACC
During FP Div or MQ
'f
I Time
Next Instruction
t
t
Reset FP
Divide Trigger
11 (Dl)
2.10.52.1
f
Reset FP
OV Trigger
11 (Dl)
2.10.52.1
FIGURE 5.3-74. FLOATING POINT TRAP MODE
142
1 ---SB 16
E Time
2.10.50.1 .J~
ACC Overflow---.J
or Underflow
Reset FP
Trap Trigger
11 (Dl)
2.10.51.1
I-SB 17
E Time
2.10.50.1 .-J~
MQ Overflow----.J
or Underflow

IBM 7090 Specifications

General

Category	Mainframe Computer
Introduced	1959
Transistor-based	Yes
Word Length	36 bits
Add Time	4.8 microseconds
Memory	Core memory
Memory (words)	32, 768 words