SCELBI Menu Options

TERMINAL

With the default settings, the terminal window emulates a 110 Baud Teletype, connected to a SCELBI with a SCELBI TTY interface.  This interface interfaces with the SCELBI CPU with a single output latch for transmit and another for receive.  This is often called "bit banged" I/O.  The baud rate is completely under control of how fast the 8008 reads and writes bits to these ports.  I have been able to write 8008 code that supports a baud rate of up to 2400 baud.  The terminal supports baud rate settings of 110(default), 300, 1200 and 2400.  MEA assumes a baud rate of 110.  Output and input will not work, if the 8008 software and terminal settings do not match.

The terminal also optionally supports automatically issuing a line feed when a CR is encountered.  MEA requires CR and LF to be issued separately from software.

The terminal defaults to the assumption that input and output data has the most significant bit set.  The terminal setting can be changed using the menu, if software is encountered that uses different assumptions.

MEMORY

The memory menu allows configuring memory to 4k SRAM(like the original 8H), 16K SRAM or 12K SRAM along with 4K EPROM loaded with MEA.  Note that with the 4K (SCELBI-8H) configuration, all programs must be loaded with the front panel controls or Intel Hex files.

Memory can be zeroed out with the "Clear" command.  This can be helpful when the system state is in a problematic mode.  For instance SCELBAL assumes that the first command issued is "SCR".  If "SCR" is not the first command issued, you may need to clear memory and reload SCELBAL to get it into a working state.

The load command allows you to load an Intel Hex formatted object file directly into emulated memory.  Though this feature did not exist on real SCELBI mini-computers, this cheat is much faster than than loading through the cassette interface, which can take 5 minutes or longer to load a full memory image into a SCELBI-8B. 

SOUNDS

This menu, allows you to disable all and individual sound output from the SCELBI emulator.  Note that the cassette playback sound is not perfectly synchronized to actual tape reads, but will give you an approximate idea of how the read is progressing.  Tape sound output while recording is not currently implemented.