1. The U880 CPU within the Robotron 1715
A PROJECT BY
Johannes Jähn
Michael Riedl
Florian Leithäuser
Gerd Utecht
For Prof. Dr. Abzug, CS350, 12/08/1998

2. The U880 CPU within the Robotron 1715
Personal Computer
Build from by
Most common OS’s
Size (WxDxH) in cm
Weight Kg
Languages
PC1715, 1715W
1985 to 1990
VEB Büromaschinenwerke Sömmerda
SCP 3.2, CP/A, BROS, JAMP
50 x 40 x 14
12,8
Basic, Pascal, Assembler, Fortran

3. The U880 CPU within the Robotron 1715
Clock Speed
Registers
RAM
ROM
Interfaces
Resolution
FDDs etc.
Kind of Case
Keyboard
UA880
4 MHz
8 bit
64 KB (Max. 256 KB)
2 KB
Keyboard, Monitor, V.24, 2 x FDD slots, Printer
Text: 64 x 16 or 80 x 24
2 x 5,25" 720 KB
Desktop with FDD, separate monitor & keyboard
QWERTY, separate number block, 98 keys
15 Function keys

4. The U880 CPU within the Robotron 1715
Instruction Set: native instructions
177 additional instructions
1, 2, 4, 8 & 16 bit instructions
all common shift operations ( logical, arithmetical, circular)
based on Z80 instructions but not compatibale

5. The U880 CPU within the Robotron 1715

6. The U880 CPU within the Robotron 1715

8. The U880 CPU within the Robotron 1715

9. The U880 CPU within the Robotron 1715
Addressing Modes:
Direct Mode
Immediate Mode
Indexed Mode
Indirect Mode

10. The U880 CPU within the Robotron 1715

11. The U880 CPU within the Robotron 1715
The Memory Organization
A) 64k version
Addressing from FFFF
+ external 2k ROM
+ 2k Interlace Refresh Memory
B) 256k version
Addressing from FFFF

12. The U880 CPU within the Robotron 1715
THANK YOU!
Please download our presentation and term paper at