from Wikipedia:

The Pentagon (Пентагон) home computer was a clone of the British-made Sinclair ZX Spectrum 128. It was manufactured by amateurs in the former Soviet Union. Its PCB was copied all over the USSR, which made it the most widespread Soviet ZX Spectrum clone. Many simple devices (upgrades) were invented to connect to the Pentagon with a soldering iron.

The last Pentagon model was the Pentagon 1024SL v2.3, which included most of the upgrades of the standard Spectrum architecture, including 1024 KB RAM, Beta 128 Disk Interface and ZX-BUS slots (especially for IDE and General Sound cards). This model also featured a "turbo" mode (7 MHz instead of the original's 3.50 MHz).


Release date 	1989
Operating system 	Sinclair BASIC, TR-DOS
CPU 	КР1858ВМ1/3, Т34ВМ1, Z80A, B, H @ 3.5 MHz
Memory 	48 to 1024 KB
Website 	pentagon.nedopc.com


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from WoS:
(see image)

Total in line : 32 + 36 + 128 + 28 = 224 tacts
Total in frame: 16 lns + 64 lns + 192 lns + 48 lns = 320 lines

from begin of INT: 3584t + 14336t + 43008t + 10752t = 71680tacts
80 lines = 17920 tacts

pentagon has no slow memory. neither scorpion. 

Kio:

INT is at start of FFB, not at start of screen, so it is 16 lines earlier than on a standard ZX Spectrum.
INT seems to be 36 cc long. (-> sblive.narod.ru image)