This version adds support for the Altair Minidisk in addition to the standard 8 inch Altair floppy. The Minidisk's different data transfer rate, sector timing, motor start-up delay, motor shutdown, etc. are all accurately emulated. When the drive type is changed in the Configuration Monitor, the type of all three drives is changed, so be sure to upload the appropriate media into the drives whenever drive type is changed. Disk images for Minidisk BASIC, Altair DOS and CP/M are available on the support page.
This update also improves the "transparency" of using the Configuration Monitor while an 8080 program is running. When an 8080 program is paused via the front panel and the Configuration Monitor is used to to change a floppy, change baud rate, etc., it is desirable that the 8080 program be able to pick up and run again without any issue. However, prior to this update, some aspects of the emulated hardware were re-initialized after exiting the Configuration Monitor. This re-initialization caused some problems - primarily with software that used interrupts. With this update, the following changes have been made when exiting the Configuration Monitor and resuming the 8080 program:
- Interrupt flags and interrupt enables of emulated 8080 hardware are no longer cleared
- The 8080 processor interrupt state is maintained
- 60hz real-time interrupts from the 88-VI/RTC remain on if enabled on the emulated hardware
- Emulated serial port registers are not cleared/re-initialized
- Floppy drive state, including track number, is not reset. If a drive was selected, it remains selected.
Feel free to contact me or post with any questions!