RobertCX
ASCI u68 System X
This is probably one of the most attractive vintage computer systems I own, and the only one which is partially made of wood!
Its a 6800-based system, taking up to two 2716 EPROMs and has 1K of RAM, a 6821 user PIA, and a serial interface. The keypad is very nice indeed, with full-travel typewriter-style keys with transparent tops, allowing clear legends to be inserted. The other two 6821 PIAs are dedicated to the keypad and LED display - the multiplexed LED display is a bit on the dim side.
The monitor program can either operate over the local keypad, or over the serial port, but there is a "gotcha", insofar that the serial reception will only work if pin 6 is fed with an active signal - given that this is supposed to be an output pin (in the RS232 standards), either a special serial cable or a PCB modification is required. After reset, the system waits for either a local keypress, or a serial character, which it attempts to auto-baud to (rates from 110 to 9600 are supported).
The card frame accepts two cards; apparently, one form of expansion card was a BASIC card, and there is some support within the monitor program to access it.
The monitor supports loading and dumping to the serial port, though with a rather strange proprietary format - it appears to be designed to interface to a dedicated digital tape recording unit.
As you can see from the photos, the 16 keys are dual-function, behaving either as command keys or hexadecimal keys. This is a bit limiting, compared to having at least some dedicated command keys; any mistake entering addresses, etc. cannot be corrected, and you have to go ahead with the duff command or reset the unit before entering the correct command. And some functions such as Auto data entry can only be exited by resetting the unit, as there is no dedicated "Escape" key. There is no direct feedback as to what mode you are currently in (command mode or data entry mode), so the next keypress may yield unexpected results.
ASCI u68 System X
This is probably one of the most attractive vintage computer systems I own, and the only one which is partially made of wood!
Its a 6800-based system, taking up to two 2716 EPROMs and has 1K of RAM, a 6821 user PIA, and a serial interface. The keypad is very nice indeed, with full-travel typewriter-style keys with transparent tops, allowing clear legends to be inserted. The other two 6821 PIAs are dedicated to the keypad and LED display - the multiplexed LED display is a bit on the dim side.
The monitor program can either operate over the local keypad, or over the serial port, but there is a "gotcha", insofar that the serial reception will only work if pin 6 is fed with an active signal - given that this is supposed to be an output pin (in the RS232 standards), either a special serial cable or a PCB modification is required. After reset, the system waits for either a local keypress, or a serial character, which it attempts to auto-baud to (rates from 110 to 9600 are supported).
The card frame accepts two cards; apparently, one form of expansion card was a BASIC card, and there is some support within the monitor program to access it.
The monitor supports loading and dumping to the serial port, though with a rather strange proprietary format - it appears to be designed to interface to a dedicated digital tape recording unit.
As you can see from the photos, the 16 keys are dual-function, behaving either as command keys or hexadecimal keys. This is a bit limiting, compared to having at least some dedicated command keys; any mistake entering addresses, etc. cannot be corrected, and you have to go ahead with the duff command or reset the unit before entering the correct command. And some functions such as Auto data entry can only be exited by resetting the unit, as there is no dedicated "Escape" key. There is no direct feedback as to what mode you are currently in (command mode or data entry mode), so the next keypress may yield unexpected results.