Msu (Memory Super-Charger Unit) - Gestetner A193 Service Manual

IMAGE PROCESSING

2.5 MSU (MEMORY SUPER-CHARGER UNIT)

IPU
C P U
The MSU consists of the memory controller and the DRAM. The functions of
each device are as follows.
Memory Controller:
DRAM (standard 4MB):
The data which was treated with binary picture processing is sent to the
MSU. The data is first compressed using the MMR (modified modified read)
process and the compressed data is stored in the DRAM. When printing, the
data from the DRAM goes back to the memory controller, where the data is
decompressed and image editing is performed (e.g., image rotation, repeat
image, combine image).
The memory capacity changes when optional memory is installed onto the
MSU board. The copier functions for each memory combination are as
follows.
Multi duplex copy
Sort, Rotate Sort A4, LT
B4, LG
A3, DLT
Number of pages A4 6%
ITU-T#4
(12% black)
(A193)
M e m o r y
Controller
B U S
BICU
Standard (4 MB)
X
O
X
X
35
15
2-16
D R A M
Compressing the 1-bit image data
Image rotation
Image data transfer to the DRAM
Stores the compressed data (2 MB)
Working area (2 MB)
Optional 4 MB
O
O
O
O
99
45
X: Not Available
M S U
A193D528.wmf
Optional 8 MB
O
O
O
O
99
75
O: Available
SM