3202
3202 is the ND-120/CX CPU board. The same identifier (variants 350175/350176/350177/350178) is used for ND-125/CX CPU boards. The difference is that the 125/CX has faster on-board memory access and includes more on-board memory (8/12/16 MB, the 120/CX can have up to 6MB RAM on-board).[1]
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Introduction
It contains the CPU, bus arbitration logic, memory control, memory and other subsystems. It also has the Real time clock and the I/O for the serial console.
Switches and indicators
- SW3 - Master Clear - normal position = central. This switch may be depressed to give a hardware master clear to the CPU.
- TH1 - ALD select
- TH2 - Baud rate select
- LED3 - self test passed (green)
- LED2 - self test fail (red)
- LED1 - cache OFF (red)
- SW1 - Cache ON, normal position = down.
- LED6 - CPU grant (green)
- LED7 - bus grant (yellow)
- SW2 - Memory OFF, normal position = down.
- LED4 - parity error (red)
- LED5 - parity disable (red)
- SW4 - Parity disable, normal position = down.
- upper limit display
- 000 - memory off (SW2)
- 100 - 2M Bytes onboard memory
- 200 - 4M Bytes onboard memory
- 300 - 6M Bytes onboard memory
Connectors
The A and B connectors are used for I/O, the C connector is used for the ND-100 Bus.
I/O Devices on the card
none?
ECO
ECO or Engineering Change Order is a hardware change. Here is a list of known ECO's for this card.
- ECO 100-751 - Gives false interrupt, IOX error, MOR or Protect violation[2]
- ECO 100-752 - Sintran corruption when heavy load on the bus[2]
- ECO 100-763 - Sintran hangs or gives ILLEGAL INSTRUCTION.[2]
- ECO 100-774 - Memory out of range[2]
- ECO 100-779 - System failing with cache enabled[2]
- ECO 100-785 - Memory out of range, IOX-error[2]
- ECO 100-786 - Upgrade ND-120CX CPU & MM 32B 2MB to ND-125CX[2]
- ECO X01 - New backup battery for the calendar on ND-120 CPU[2]
Microcode
The microcode for the CPU is held in two EPROMs, AM 27256 32KB.
Location: the board has letters for rows (A, B, C, ...) on the left edge, and numbers (1, 2, 3, ...) at the top edge. Location of any given component on the board is given as a single letter and number (for small components) or as a series of letters and numbers (for larger components, covering more than one row and / or column).
Dumps of the chips, made with a EPROM programmer
- Top chip: File:AM27256 45132L B22.bin.bz2 Location on board: B-22-23 (Schematic says 23B, bits 0-7)
- Bottom chip: File:AM27256 45133L B24.bin.bz2 Location on board: B-24-25 (Schematic says 26B, bits 8-15)
This is version L (100014/oct) of the microcode.
(which appears to be a minor bugfix from K version, in the ELEAV function)
Reference
- Norsk Data Document ND–30.008.3 EN ND-100 Hardware Maintenance , page 255