King's Quest II Booters on PCjr

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Re: King's Quest II Booters on PCjr

Postby fsmith2003 » Sun Oct 14, 2018 10:27 am

Im new to the scene so I may be wrong but is JRCONFIG something that can be used for Booter games since it doesn’t load DOS?
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Re: King's Quest II Booters on PCjr

Postby Brutman » Sun Oct 14, 2018 10:38 am

The general rule of thumb is that the early booter games do not use device drivers like JRCONFIG even if they have been cracked to run on DOS. Games like Kings Quest or Flight Simulator expect to manage memory themselves and will move/resize the video buffer as they see fit. Having JRCONFIG get in there first and move things around is going to have no effect, or worse, confuse things and cause a crash.

This is documented elsewhere but JRCONFIG and memory managers like it use a two stage booting process to do their magic. The first time the machine boots and loads the device driver the machine looks like a 112KB DOS machine because the video buffer is at the default location (the top of memory) and even though the BIOS counted extra RAM, it only reports 112KB to DOS because DOS memory has to be contiguous.

When JRCONFIG runs the first time, it moves the video buffer to a lower location, sets up whatever RAM disk area you might want (depending on the /S option), fills in a new number of available RAM to report to DOS in the BIOS RAM area, and then does a warm reboot. Now during the warm reboot DOS sees a lot more RAM that is contiguous because DOS is being told to load *above* the relocated video buffer, not below it. The extra warm boot is the reason why you hear the floppy drive reset and seek twice when JRCONFIG is used instead of just once when plain DOS is used.

Booter games that understand the PCjr never needed this effort. They just boot, detect they are on a JR, move the video buffer as appropriate, and then continue to load. Converted Booter games are kind of a wild card ... it depends on who did the conversion.
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Re: King's Quest II Booters on PCjr

Postby fsmith2003 » Sun Oct 14, 2018 10:49 am

Ok cool. Some good info to know there. So, to respect to this thread, this particular KQ2 image has likely been altered in someway to “confuse” the PCJr into thinking there isn’t enough ram available then?
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Re: King's Quest II Booters on PCjr

Postby Hargle » Mon Oct 15, 2018 11:13 am

I mailed a copy of the original disks to Hargle and confirmed they were working. Not sure if he's pulled fresh images off of those disks yet, but yeah, the ones that had been circulating from Retrograde Station (which you have) are definitely not "real PCjr" friendly.

Pretty sure I dropped the ball on this. Let me dig around my place over the next few days and see what I can find out.
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Re: King's Quest II Booters on PCjr

Postby KenG » Mon Oct 15, 2018 1:06 pm

Chuckphd53 wrote:Not sure if it related, but I had issues using the JRCONFIG /S option and some games, I had to take it out and have NO mem associated to ramdisks...


Since this is a booter game, there are no drivers loaded other than whatever the game itself loads. I do wonder if some of the BIOS extensions provided by the jr-IDE could cause issues.
Enhanced PCjr with a jr-IDE (1GB DOM) and a parallel port side car with a compact flash reader and backpack 1.44mb floppy attached. Tandy video mod.
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Re: King's Quest II Booters on PCjr

Postby fsmith2003 » Mon Oct 22, 2018 2:03 pm

So far I have not been able to get any image or downloaded version of KQ2 to play on my PCjr with jrIDE. Has anyone had any luck with this in some form?
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Re: King's Quest II Booters on PCjr

Postby Hargle » Tue Oct 23, 2018 6:53 am

I expect to be able to dig into my image collection in the next two days to help here. standby.
---

Mixed news. I have KQ2 v1.1h disks that boot and work on a PCjr. I am able to create additional disks using my transcopy board of them.
I confirmed that the .IMA/.IMG files of v1.1h which have CRC32's 4107b044 (disk1)and 66d16848 (disk2) report the "not enough memory" error.
These disk images boot fine in DOSBox.

KQ2 v1.0w IMG/IMA disk images with a CRC of b5569081 (disk1) and 8e605724 (disk2) do not boot on a PCjr- they continuously return to the boot menu.
These disk images boot fine in DOSBox.

I do not have any KQ2 v1.0w copies that work on the PCjr.
I have found that the disk protection from the Black Cauldron v1.1J is identical to v1.0w of KQ2, so I'm currently hunting for working images of BC 1.1J so that I can perhaps replicate the copy protection from BC and transfer it to one of my bad copies of KQ2 v1.0w. I've run out of time today to pursue this. I have an original black cauldron set of disks which do boot on the PCjr, but I cannot figure out how to find what version number it is.
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Re: King's Quest II Booters on PCjr

Postby Hargle » Fri Oct 26, 2018 3:00 pm

For anyone interested in images to use, send me a PM.
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