Running Windows on the PCjr.

[jmetal88]

Eh, we have few enough new threads around here that I really don't think it matters, yet.

By the way, I noticed on a 736k PCjr, if you load Windows totally above the lower 128k, it is significantly faster than if any portion gets loaded into the lower 128k.

[Vorticon]

How about Linux on the Jr?

[Brutman]

ELKS (Embedded Linux Kernel Subset?) might work on a Jr, but it has to be patched to deal with the non-standard memory map. It's also quite dead as far as development goes. I also have a problem thinking of a Unix-like OS that doesn't have any process protection.

Another worthy project would be to get FreeDOS running on the Jr. It might work as is with Jrconfig.


Mike

[Eric]

ELKS (Embedded Linux Kernel Subset?) might work on a Jr, but it has to be patched to deal with the non-standard memory map. It's also quite dead as far as development goes. I also have a problem thinking of a Unix-like OS that doesn't have any process protection.

Another worthy project would be to get FreeDOS running on the Jr. It might work as is with Jrconfig.


Mike

The thought of patching freedos to run on PCjr has always been an exciting thought. BTW, it was some time ago, but I've noticed you posted a bit about this thought on the freedos forum.

I'd try it with JRConfig, but I don't have any way to get software on my disks... yet.


Thread /Revived

[jmetal88]

I don't see FreeDOS being very feasible on the PCjr. It's a bit heftier than MS-DOS or PC-DOS. Maybe a version specifically compiled for the PCjr with less features and support for fewer file systems would work.

[Brutman]

I think you are wrong there. FreeDOS might require a little bit more memory, but with a 640K or 736K machine I'm not concerned. It's been a long time since I had to absolutely run something huge on the machine; when that happens now I just fire up the 386-40. Or the 486-33. Or the Pentiums .. you get the idea.

The problem with FreeDOS is that it assumes a clone PC. So here are the problem areas:

• The PCjr memory hole. (Might be solved already by using a device driver like jrconfig
• The nonstandard keyboard handling; should be handled at the BIOS level but we need to make sure that FreeDOS doesn't install its own handler. (MS-DOS 5+ and PC-DOS 5+ do, which is a problem on the Jr.)
• Other miscellaneous things being out of place .. INT5 is used by the video adapter. NMI is used by the keyboard instead of IRQ1. There is no DMA. Etc. Some of these things might be hidden by the BIOS.

It's on the todo list ... I'm on the FreeDOS developer and user mailing lists, and I have a little bit of credibility since FreeDOS started shipping mTCP in their 1.1 release. So I'm sure that I'll get help when the time comes.

[Eric]

I've heard that FreeDOS is capable opf running on 8088s, but most of the bundled freeware requires a 486. Then again, I haven't attempted to run FreeDOS on anything lower than a 386 and hearing claims is very different than testing and confirming. Have any of you attempted to run FreeDOS on a 5150?

I'd try to, but I don't have an IBM PC.

[jltursan]

GEM, by contrast, works great! Yeah, there's no multitasking, but at least it is a GUI!

I used to work with GEM and a beefed up XT clone from Amstrad (PC-1640) around 1989 and it's true, it worked great. It was fast and practical and one day...it faded away

I have a V20 and I've done the speed up mod to run it at 8mhz. It's still too slow to be useful

Don't want to hijack the thread; but, where can I get the details for such mod?

[Eric]

Don't want to hijack the thread; but, where can I get the details for such mod?

There's a file in the PCjr Club Archive called speedup.txt that covers the modification. It is actually rather simple.



I forgot what the link to the compressed folder is, so I'll upload the txt file as an attachment.

[jmetal88]

I think Mike only puts the compressed PCjr archive up on the server by request, so the link might not do any good unless you get it directly from Mike anyway.

I have noticed most of the stuff it contains is available on theoldcomputer.com, though. Just be aware there is some 'grey-area' content on the site, and it likes to show you ads and pop-ups before you get to the download. Some of the downloads require you to sign up, too.