HxC Gotek on IBM PCjr Works only single-sided

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JudgeMonroe
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Joined: Sat Jul 04, 2020 9:10 am

HxC Gotek on IBM PCjr Works only single-sided

Post by JudgeMonroe »

Hello. I recently acquired a Gotek and the HxC firmware for use on an IBM PCjr. I did not have any trouble installing the bootloader or the firmware, but the behavior of the emulator on my PCjr is suboptimal.

Only single-sided disk images work, meaning 180k images like the PC-DOS 2.1 disk and some older booter disks.

Double-sided (360k) images don't boot ("Disk Boot Failure"), don't format correctly (only 180k is formatted), and when inserted software fails to load from them ("Sector not found.")

At first I was using the "Indexed Mode" configuration file and then tried setting internal parameters directly in case "AUTO" wasn't sufficient:

0: 4 [IBM PC AT/XT]
1: 1 [IBM PC DD]
4: 2 [INDEXED MODE]

This didn't help, so I reset the parameters and set only the [INDEXED MODE].

The Gotek jumper is on S1. I have tried both HFE and IMG disk images.

Jeff
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Re: HxC Gotek on IBM PCjr Works only single-sided

Post by Jeff »

JudgeMonroe wrote:
Sat Jul 04, 2020 9:34 am
Hello. I recently acquired a Gotek and the HxC firmware for use on an IBM PCjr. I did not have any trouble installing the bootloader or the firmware, but the behavior of the emulator on my PCjr is suboptimal.

Only single-sided disk images work, meaning 180k images like the PC-DOS 2.1 disk and some older booter disks.

Double-sided (360k) images don't boot ("Disk Boot Failure"), don't format correctly (only 180k is formatted), and when inserted software fails to load from them ("Sector not found.")

At first I was using the "Indexed Mode" configuration file and then tried setting internal parameters directly in case "AUTO" wasn't sufficient:

0: 4 [IBM PC AT/XT]
1: 1 [IBM PC DD]
4: 2 [INDEXED MODE]

This didn't help, so I reset the parameters and set only the [INDEXED MODE].

The Gotek jumper is on S1. I have tried both HFE and IMG disk images.
I recommend to try HFE files first. The HFE contains the exact disk format, IMG/DSK doesn't and the emulator try to guess it... (And probably fail here...). (Use the HxC Software to check the disk geometry with the viewer).
For img files i recommend also to set the system family to help the emulator to choose the right disk geometry.

Can you try to format an HFE and check it with the hxc software disk/track viewer ?

JudgeMonroe
Posts: 2
Joined: Sat Jul 04, 2020 9:10 am

Re: HxC Gotek on IBM PCjr Works only single-sided

Post by JudgeMonroe »

I recommend to try HFE files first.
I have started over with all HFE files that I have created myself with the HxC software (load/export) and have had mostly good results formatting, reading and writing both 360k and 720k disk images (within DOS constraints). It is disappointing that I can't use "off the shelf" IMG files that work in other emulators and Virtual Machines.

The problem that remains is that about 60% of the time even an HFE DOS disk will not boot ("DISK BOOT ERROR") and I have to reboot over and over until it works.

Also when using COPY on a lot of files and "switching" disks I frequently get "disk not ready" when inserting the source disk unless I give it a solid 2- or 3-count to get ready.

I wonder if these issues are timing-related and if there's a setting you recommend adjusting?

Jeff
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Re: HxC Gotek on IBM PCjr Works only single-sided

Post by Jeff »

This look like a PC <> Shugart miss-configuration issue.

I suspect that you are using the wrong interface mode and/or the wrong jumper setting.

Is the jumper set to S1 ?

For the IMG you may need to force the interface mode. (Please share some of them btw)
(IMG files should work !)

What is the old floppy disk drive jumper settings ?

EDIT : I see others HxC users with the S0 jumper setting on this machine, so i suspect you need to set the emulator in "Generic Shugart" mode too. See "Internal parameters settings" on this page :

viewtopic.php?p=16457#p16457

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