A 8 bit fixed disk MFM controller
It is immediately noticeable that this controller looks amazingly similar to the CTT Munich IT-805. But a look at the content of the BIOS shows that it is two years older (1989) and of different manufacturer.
The hard disk controller is a NEC 7261AD ceramic chip with 12 MHz.
- ROM BIOS: 0xC8000
- I/O Port: 0x320
- IRQ: 5
The BIOS is basically of type 2764 or 27C64A, i.e. it is 8 KByte in size. The BIOS contains the following string:
(C) COPYRIGHT Transteque Co., Ltd. 1989, Ver. 2.03
After several attempts I found that the BIOS ROM chip was defective. With my GALEP 5 I simply burned a new BIOS to a M5L2764K-2.
This Controller has it's own "HARD DISK FORMAT MENU". Please use this for LOW LEVEL FORMATTING (LLF)! Please note the slightly different start address; C800:6 instead of C800:5. See also here.
Start low level formatting with: .....
DEBUG (ENTER) -G=C800:6 (ENTER)
Start HARD DISK PARK UTILITY with: ...
DEBUG (ENTER) -G=C800:9 (ENTER)
If the controller does not recognize the hard disk parameters at startup, the low level formatting starts automatically!
I have formatted a ST225 and a ST238 for test purposes and have not noticed any problems.
- HC-100: Owner's manual
- ROM BIOS: Download (8 KByte) / The chip is a "2764" or 27C64A". I tested the BIOS with an ATMEL AT28C64B (EEPROM) and a Mitsubishi M5L2764K-2; both work fine.