VOGONS


First post, by kikendo

User metadata
Rank Member
Rank
Member

Is there any emulator for PCjr that will run on a Pentium II?
Is this one the only option? http://www.oldskool.org/pc/tand-em/tand-em_docs.html

I got a hold of a bunch of IBM PCjr software, and I cannot find a software repository online anywhere. I want to check against what I have, I think I can contribute a bunch of disks to the online community.
But I also have to test the disks so an emulator should be necessary.

Reply 1 of 27, by VileR

User metadata
Rank Oldbie
Rank
Oldbie

I've never really tried Tand-Em, but it claims that only the Tandy BIOS ROM is supported (PCjr is slated for "a future release"). It's also 20 years old, and a lot of the machine-specific research has accumulated since then. Wouldn't get my hopes up.

DOSBox on a Pentium II *might* be able to pull off PCjr speeds... it's a possibility.

Should be interesting to see a list of what you've acquired, in any case.

[ WEB ] - [ BLOG ] - [ TUBE ] - [ CODE ]

Reply 2 of 27, by Jorpho

User metadata
Rank l33t++
Rank
l33t++
kikendo wrote on 2020-05-20, 13:37:

But I also have to test the disks so an emulator should be necessary.

Why not just use standard floppy disk surface-testing software?

Reply 3 of 27, by comp_ed82

User metadata
Rank Newbie
Rank
Newbie
VileR wrote on 2020-05-25, 22:35:

DOSBox on a Pentium II *might* be able to pull off PCjr speeds... it's a possibility.

Not too long ago, I was running DosBox 0.72 + 0.74 (vanilla, not Daum) on a Mobile Pentium II-366.
I was able to get about mid level 386 performance (Blake Stone was playable at full screen size, but not full screen Doom or DN3D), so PCJr emulation at full speed should not be a problem.

Reply 4 of 27, by kikendo

User metadata
Rank Member
Rank
Member
Jorpho wrote on 2020-05-25, 23:19:

Why not just use standard floppy disk surface-testing software?

Because that's not gonna tell me what the disk contains. A lot of these disks are poorly labeled or just unlabeled.
As for what I got that seems most interesting, there seems to be a lot of disks from a public domain library. That's the kinda software that usually gets lost the easiest.
The previous owner seems to have been part of a PCjr user group.

Last edited by Stiletto on 2020-06-03, 21:04. Edited 1 time in total.

Reply 5 of 27, by Caluser2000

User metadata
Rank Oldbie
Rank
Oldbie

mbrutman of mTCP fame specializes in PCjr and has a web site full of good intfo. Sometimes he comes here and he spends a lot of time helping folk over at vcfed.org forums. Might pay to ask there. Trixter who owns oldskool.org is also over there and posts often. Doesn't take much to join up.

Last edited by Caluser2000 on 2020-06-03, 19:52. Edited 1 time in total.

There's a glitch in the matrix.

Reply 6 of 27, by Jorpho

User metadata
Rank l33t++
Rank
l33t++
kikendo wrote on 2020-06-03, 16:31:

Because that's not gonna tell me what the disk contains. A lot of these disks are poorly labeled or just unlabeled.

If you just want to see what's on them, then why do you need an emulator? Are these "booter" disks that do not have a standard MS-DOS filesystem?

Reply 7 of 27, by mbbrutman

User metadata
Rank Member
Rank
Member

I don't see why emulation is needed to identify the diskettes. You should be able to read the diskettes and create images of them, except for the copy protected sectors. From the images you can search for strings to get an idea of what is on the diskette.

Reply 9 of 27, by kikendo

User metadata
Rank Member
Rank
Member
mbbrutman wrote on 2020-06-03, 22:45:

I don't see why emulation is needed to identify the diskettes. You should be able to read the diskettes and create images of them, except for the copy protected sectors. From the images you can search for strings to get an idea of what is on the diskette.

What is the best program to use to make images of the disks?
I do not own or intend to own a greaseweazel, kryoflux or anything like that. These disks are not write protected. Can I use something like win32diskimager, but that runs on Windows 98? Is there such a thing?

Reply 10 of 27, by Jorpho

User metadata
Rank l33t++
Rank
l33t++
kikendo wrote on 2020-06-10, 16:10:

What is the best program to use to make images of the disks?
I do not own or intend to own a greaseweazel, kryoflux or anything like that. These disks are not write protected. Can I use something like win32diskimager, but that runs on Windows 98? Is there such a thing?

Gee, I'd heard of the old Catweasel, but the Greaseweasel is new to me. (The way people can't agree on spelling doesn't help matters. Greaseweazle?)

Anyway, WinImage comes up a lot, but that costs money. I suggest RawWriteWin, which definitely runs under Windows 98.

Whether or not the disks are write-protected is unimportant – in fact, you'd kind of want the disks to be write-protected in order to avoid inadvertently writing to them, and if they still have a functional write-protect tab, I suggest you enable it. But as noted above, there are all sorts of wacky copy-protection tricks that standard floppy hardware will not accurately capture regardless of what software you use – things like "fuzzy bits" that are purposefully not supposed to be read consistently.

But none of that is really important if you're just trying to establish whether the contents of these disks have already been archived somewhere.

Reply 11 of 27, by kikendo

User metadata
Rank Member
Rank
Member
Jorpho wrote on 2020-06-10, 17:23:

Gee, I'd heard of the old Catweasel, but the Greaseweasel is new to me. (The way people can't agree on spelling doesn't help matters. Greaseweazle?)

I also am always unsure how it is spelled 😁
It's a new, open source kryoflux alternative.

I suggest RawWriteWin, which definitely runs under Windows 98.

Thanks so much! I will try this ASAP.

Whether or not the disks are write-protected is unimportant

Gigantic facepalm. I meant to say "copy-protected". My bad. These disks will be plain readable by an image maker. No funny bits going on.

But none of that is really important if you're just trying to establish whether the contents of these disks have already been archived somewhere.

From what I have seen today when I managed to install a 5.25" drive in my main machine, most of these disks contain old data files, nothing that has to be preserved. Also seems like whatever the labels say IS what's on the disk 80% of the time, so judging by labels, I can look up the contents around.

I'm mostly interested in the Public Domain library disks that are here, that's the kinda stuff that usually disappears. There's a whole bunch of disks coming from a New York IBM Users Group pubic domain library.

EDIT:
I tried RawWriteWin but it doesn't work. I think it's only good for 1.44MB disks. These are, I think all, 360KB DSDD disks.
Thanks for trying but I guess I need a different tool, maybe I need one for DOS instead of Windows 98?

Reply 12 of 27, by VileR

User metadata
Rank Oldbie
Rank
Oldbie
kikendo wrote on 2020-06-11, 00:37:

I tried RawWriteWin but it doesn't work. I think it's only good for 1.44MB disks. These are, I think all, 360KB DSDD disks.
Thanks for trying but I guess I need a different tool, maybe I need one for DOS instead of Windows 98?

I recently went on a similar dumping mission (some >100 non-protected / non-original 360KB disks) and these 2 DOS tools did me good:

  • Dave Dunfield's ImageDisk - great for archival, and for handling most problems (outside of copy protection) that other tools don't. Be sure to have a look at the docs for the correct parameter(s) to use with your drive. It also includes a utility to convert the resulting .IMD to a raw-sector dump (.IMA/.IMG) for use with emulators, WinImage/ImDisk etc.
  • Trixter's disk2img - a more quick-'n'-dirty type of tool. Useful for disks that are close to failing (and sometimes stump IMD), as it can read entire tracks at a time and has a bunch of options for retry/recovery strategies.

If you need to look into out specific data errors, or have a disk that refuses to read all the way from track 0 to track 39, look up something called Anadisk - it helps analyze what's wrong and make *partial* dumps when all else fails.

Protip: if you see a "Wabash" label on a disk, then for your drive's sake, don't even try. KILL IT WITH FIRE.
Good luck 😉

[ WEB ] - [ BLOG ] - [ TUBE ] - [ CODE ]

Reply 13 of 27, by Benedikt

User metadata
Rank Member
Rank
Member
Jorpho wrote on 2020-06-10, 17:23:
kikendo wrote on 2020-06-10, 16:10:

What is the best program to use to make images of the disks?
I do not own or intend to own a greaseweazel, kryoflux or anything like that. These disks are not write protected. Can I use something like win32diskimager, but that runs on Windows 98? Is there such a thing?

Gee, I'd heard of the old Catweasel, but the Greaseweasel is new to me. (The way people can't agree on spelling doesn't help matters. Greaseweazle?)

That reminds me...
I still have to port Greaseweazle to my own adapter boards. Oh well, maybe later.

Reply 14 of 27, by kikendo

User metadata
Rank Member
Rank
Member
VileR wrote on 2020-06-11, 08:17:
I recently went on a similar dumping mission (some >100 non-protected / non-original 360KB disks) and these 2 DOS tools did me g […]
Show full quote

I recently went on a similar dumping mission (some >100 non-protected / non-original 360KB disks) and these 2 DOS tools did me good:

  • Dave Dunfield's ImageDisk - great for archival, and for handling most problems (outside of copy protection) that other tools don't. Be sure to have a look at the docs for the correct parameter(s) to use with your drive. It also includes a utility to convert the resulting .IMD to a raw-sector dump (.IMA/.IMG) for use with emulators, WinImage/ImDisk etc.
  • Trixter's disk2img - a more quick-'n'-dirty type of tool. Useful for disks that are close to failing (and sometimes stump IMD), as it can read entire tracks at a time and has a bunch of options for retry/recovery strategies.

Thanks for this! Yesterday I went and used WinImage. Is there a problem with it besides it being paid? Are the IMA files it makes good?
So far since I am well within the evaluation period, no issues, but it does NOT like some disks (for example: it will not do 160KB SSDD disks). I can read such disks fine in Windows, so I might just make a manual copy.

Protip: if you see a "Wabash" label on a disk, then for your drive's sake, don't even try. KILL IT WITH FIRE.

I haven't. But what is it? 😁
I did almost kill it a couple of times with some moldy disk (disk whining/singing). I know this problem well from my C64 disks. Thankfully I did not damage anything and the offending disks have been separated.
Pro tip: always look at the surface of the disk before popping it in, give it a full rotation, mold on it can be easily spotted, looks like watermarks. Also can easily be sniffed, if you have a good nose.

Reply 15 of 27, by Errius

User metadata
Rank Oldbie
Rank
Oldbie

Wait, what. People are running DOSBox in DOS? What is this madness?

“Your mission is to attack and destroy the Apple Computer manufacturing plant. You are allotted 35 bombs and 60 lasers."

Reply 17 of 27, by VileR

User metadata
Rank Oldbie
Rank
Oldbie
VileR wrote on 2020-06-11, 08:17:

Thanks for this! Yesterday I went and used WinImage. Is there a problem with it besides it being paid? Are the IMA files it makes good?

They should be, except for the 160KB issue you've already encountered, but I don't know how well it deals with unreliable sectors. Also this is more of a Windows problem, not a WinImage problem, but if you're reading floppies in Win98 then you'd want to write-protect them as mentioned. Otherwise Win9x overwrites the OEM ID on every disk as soon as you plop it in. (http://www.os2museum.com/wp/the-ihc-damage/)

So far since I am well within the evaluation period, no issues, but it does NOT like some disks (for example: it will not do 160KB SSDD disks). I can read such disks fine in Windows, so I might just make a manual copy.

That's probably down to these disks being DOS 1.x-formatted (i.e. no boot parameter block, which winimage expects). Those two programs I mentioned will image them just fine anyway.

Protip: if you see a "Wabash" label on a disk, then for your drive's sake, don't even try. KILL IT WITH FIRE.

I haven't. But what is it? 😁

Manufacturer of the worst magnetic media ever conceived by mankind. https://forum.winworldpc.com/discussion/8845/ … of-wabash-disks

I had a couple of these Drive Destroyers in my pile, but I guess I was feeling lucky so I decided to try and read them anyway. Epic fail ensued.
Maybe I sorta *was* lucky, since it only took a few passes with some 99% isopropynol to get the drive reading again, but they're best treated as you would treat a brain-eating disease. Just say no.

[ WEB ] - [ BLOG ] - [ TUBE ] - [ CODE ]

Reply 18 of 27, by kikendo

User metadata
Rank Member
Rank
Member
VileR wrote on 2020-06-11, 16:59:

I had a couple of these Drive Destroyers in my pile, but I guess I was feeling lucky so I decided to try and read them anyway. Epic fail ensued.
Maybe I sorta *was* lucky, since it only took a few passes with some 99% isopropynol to get the drive reading again, but they're best treated as you would treat a brain-eating disease. Just say no.

Oh man that's terrible!

And thanks for all your help. I will go through the disks that weren't recognized with the tools you shared.
I still managed to image 190 disks with WinImage!

So now I have a bunch of images, but still no real way to try them out. I tested it with Dosbox on the old Pentium, and everything was too fast, unplayable or simply didn't work.
Is the web-based PCjr emulator the only PCjr emulator out there? I don't like using my browser 😒

Reply 19 of 27, by Jorpho

User metadata
Rank l33t++
Rank
l33t++
kikendo wrote on 2020-06-12, 17:15:

I tested it with Dosbox on the old Pentium, and everything was too fast, unplayable or simply didn't work.

Generally, there's really no point to using DOSBox on an old Pentium instead of on a modern PC, especially if you're working with disk images. Regardless of what kind of computer you're using, you can slow DOSBox down almost as much as you want, mainly by decreasing the number of cycles or by changing the machine type – it would be useless for the oldest games otherwise.