So, I've been attempting to get my Gotek to allow my PCjr to read high density disks through the PCjr flopper controller card. It is known that the PCjr controller is not happy with HD drives (bitrate too high at 500kbps I'm guessing is the issue).
However, with FlashFloppy (v 3.29 in my testing) and a Gotek, you can play around with settings for particular image types. So, I figured I'd give it a go and see if I could get it to work.
For 360k and 720k floppies, it's fairly easy to get it to work
config.sys (Replace # with drive number (0,1,2), if you do not have a 3Flop and can only support 1 drive anyway I don't think you need this at all, same if you have the Gotek connected to drive A (0)).
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device=driver.sys /d:# /f:0
However, with 1.2 and 1.44 MB disk (i.e. 5 1/4" DSHD and 3 1/2" DSHD respectively), we have some issues. The default for these drives is 360 RPM and 500 kbps bitrate. Since the PCjr can work with 250 kbps I tried a few things.
For config.sys, you'll need to tell it the drive is a 1.2MB drive.
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device=driver.sys /d:# /f:1
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[::1228800]
# Mandatory: Number of cylinders (1-255).
cyls = 80
# Mandatory: Number of heads (1-2).
heads = 2
# Number of sectors per track (0-256). Default is 0.
secs = 15
# Bytes per sector (128, 256, 512, 1024, 2048, 4096, 8192).
# Mandatory if @secs is non-zero.
bps = 512
# Rotational RPM. Default is 300.
rpm = 360
# Data rate in kHz (kbit/s) (eg. MFM DD = 250). Default is 0.
# 0 = based on recording mode and size of track.
# eg. 250 is MFM DD, 500 is MFM HD, 125 is FM SD.
rate = 500
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rpm = 360
rate = 250
rpm = 360
rate = 500
rpm = 300
rate = 500
rpm = 300
rate = 250
So I tried the following
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rpm = 180
rate = 250
"Sector not found reading drive A"
(note DOS 5.0)
I'll keep trying some things and may try setting up FlashFloppy to output a log to see if I can determine why it might be having issues. But it does lead me to believe I might not be totally crazy for trying to get this to work. Or it could be that DOS will be really unhappy with 180 RPM and just throws it's arms up thinking that the index marker is not coming in fast enough, I'm not sure exactly how it uses the index marker.