Auto-boot process gets stuck if it checks an IEC drive

[dansanderson]

Tested with ROM: 920377, 920386

Having an external IEC drive connected appears to hang the start-up process (no READY prompt) during a scan for AUTOBOOT.C65 if there is no such file on the at-boot mounted drive 8. If it's a drive that the MEGA65 ROM has timing issues with, the scan will get stuck and never present the READY prompt.

This is a working theory to explain user-reported behavior. We need to repro this, and confirm that the auto-boot behavior actually does check external drives, and gets stuck. Repro steps should be:

1. Check Configuration to make sure it auto-boots to the SD card, and the default disk image either does not exist or refers to a D81 disk image that does not have an AUTOBOOT.C65 file.
2. Connect an IEC external drive with known timing issues, and turn it on. The report came from someone with an Oceanic drive, but I believe many 5-1/4" drives currently don't work in MEGA65 mode in a similar way.
3. Boot the machine. A successful reproduction will get stuck after the BASIC banner is printed, but before the READY prompt appears.

[sir-lazarus]

This szenario is my default. Configure a not existing d81 image. I use a SD2IEC on IEC Port.
Booting get never stuck.

[oe3gwu]

I cant reproduce this with an SD2IEC which is not cycle correct. But granted the SD2IEC has other issues on my MEGA65.

However what I do can reproduce is, if there is no disk in the MEGA65 (also no D81) the seek for Autoboot takes way longer then on my C128DCR. Approx 10 seconds.