Tandy 1000/PCjr Video Standard

[Raven]

What the heck is this? I recall reading about it a few months ago, but can't recall everything I read. I have a Tandy 1000RL/HD and have stuck my only 8-bit VGA card in it so I can get output. It has an onboard graphics card, but I don't have any monitors (as far as I know) that are compatible.

Wikipedia says it's "an extension of CGA" according to their PCjr page. Does this mean it works on a CGA monitor? Would it blow one? Any way to make a VGA monitor work with it? How does EGA relate to this video standard, is it compatible with EGA games? Any VGA games (I guess no)?

If I were to get my hands on a PCjr monitor it would work with this computer, I assume. What is the proper Tandy variant of monitor for this machine?

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Thanks.

 

[Agent Orange]

I don't fully understand the problem. The 1000RL comes with an onboard 16 color CGA. You indicated that you have a 8-bit VGA card. Any 9-pin CGA monitor should work with the RL. But, why would you want to go that way if you can run VGA? Personally, I gave my CGA and EGA monitors away a long time ago. I run a 15" Dell LCD ($45.00 off eBAy) on my SX and it work just fine with my 8-bit "Harry Swartz" VGA card. On the other hand, if you are into collecting, and have your stuff out for show & tell, I can see where you might want to go with an original configuration. I believe your Wiki reference is talking about Tandy's 1000 series overall compatibility with the PC Jr's.

 

[Lord Moz]

Yes, any CGA monitor will work (AFAIK), and no it is not compatible with EGA only games.
However, many EGA games of that era supported Tandy video modes.

There is no way to directly connect a VGA monitor to a Tandy graphics port, but if you search eBay, there are devices that will convert CGA signals to VGA, and I'd assume they will convert TGA signals just fine.

Tandy's graphics on their earlier machines were exactly the same as the PCjr's as they were originally designed as PCjr clones. This extends to the PCjr's sound modes. Later Tandy 1000s extended both the video and sound features.

The extended video modes were:
320x200 16 colors
160x200 16 colors
640x200 4 colors

Later models added 640x200 16 colors, but this was not often supported due to lack of bios support.

You can read all about the Tandy 1000s at Tvdog's Archive and FAQ

Hope that answers some of your questions.

The Tandy 1000 series was extremely popular in the late 80s and early 90s, and nearly all the games of the era listed themselves as IBM/Tandy compatible.
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Trevor

 

[Raven]

Good point about the Tandy compatibility.

As for the "why", I want to free up my 8-bit ISA slot for a RAM expansion so that the machine can handle more tasks and games. If I can find one, maybe even an XT accelerator of some kind. I love that box and would love to use it for more things, but it's CPU (at a screaming 10mhz for an 8086 though) isn't fast enough to handle most VGA games, so it's not worth the slot usage for that.

If I can locate a monitor, free up the slot, and then locate an accelerator/ram board and hook it up the box will be far more useful.

 

[Agent Orange]

Sounds like I'm raining on your parade. Your TL should already have at least 512KB on the mobo, and can be expaned to 768KB. I'm not an expert on the TL, but I think it uses 30-pin SIMMS. Google the part number and see what you come up with. I know there are some folks on the Forum that have that memory avaiaible. If you have 768KB installed, adding a memory card won't further your cause.

 

[geoffm3]

Sounds like I'm raining on your parade. Your TL should already have at least 512KB on the mobo, and can be expaned to 768KB. I'm not an expert on the TL, but I think it uses 30-pin SIMMS. Google the part number and see what you come up with. I know there are some folks on the Forum that have that memory avaiaible. If you have 768KB installed, adding a memory card won't further your cause.

I was under the impression that on the TL if you added more memory than 640KB on the system board, this was only of use if you use the onboard video. If you're using VGA it doesn't make a difference, since this memory is in the expansion ram/rom section of memory. The onboard video memory space can be moved to this area outside of the 640k memory boundary.

In other words, you'd still need to get an EMS memory card to extend the memory beyond 640kb for the system to use.

 

[Agent Orange]

768 is max for RL. Why tie down a slot with a memory card? Any 8-bit VGA card along with 768KB onboard memory will run any Tandy game you can through at it.

 

[Lord Moz]

What you really want then would be a Tandy 1000 RSX, with onboard SVGA and 3 16bit ISA slots, regular 16bit IDE controller, Tandy 1000 sound, and 386SX 25mhz with up to 9MB ram, in the same form factor as the RL.
I've been searching for quite a while for one of them... nothing yet

I did manage a 1000 RLX, which has onboard VGA and a 286, but still has a single 8 bit ISA slot and 8 bit IDE.

The search continues...

 

[Cloudschatze]

What you really want then would be a Tandy 1000 RSX...

The 1000 RSX isn't without it's share of letdown...

...3 16bit ISA slots,...

Two 16-bit ISA slots in the 1000 RSX. (Three in the 2500 RSX.)

...regular 16bit IDE controller,...

504MB limitation.

...Tandy 1000 sound,...

This was a huge disappointment. The address port had to be moved (from 0xC0 to 0x1E0) due to the second, 16-bit DMA controller, breaking sound compatibility with the majority of software.

I did manage a 1000 RLX, which has onboard VGA and a 286, but still has a single 8 bit ISA slot and 8 bit IDE.

Depending on the intended use, the 1000 RLX is about as perfect as it gets.

 

[Raven]

I like limitations on my hardware - the fun for me is figuring out how to bypass or work around them, and max out a platform. Once it's to that point, I find all the software that will run on it and stockpile it. Finally, I play games.

 

[Lord Moz]

504MB limitation.

Fixable in software I'm sure :D

This was a huge disappointment. The address port had to be moved (from 0xC0 to 0x1E0) due to the second, 16-bit DMA controller, breaking sound compatibility with the majority of software.

I had not heard about this. Certainly a huge bummer.

Depending on the intended use, the 1000 RLX is about as perfect as it gets.

So... say I happen to have a RLX/B with DOS 5 and the "new" aka incompatible joystick ports... would you happen to know where I could get adapters to my regular Tandy joysticks? I suppose I could make adapters, but I was hoping for a finished look.

My biggest gripe with my RLX is its VGA font... I think it's horribly ugly. I might see about loading a replacement in the autoexec.bat I guess. I think I'll look into that.

I'll tell you, trying to find the ZIP drams to upgrade it from 512KB really stinks! I was lucky and happened to find someone selling some for an Amiga 3000 and they happened to work.

At least it has a regular bi-directional parallel port. I plan to try to get my parallel ethernet adapters to work, and then my parallel SCSI adapters too. Should be fun!
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Trevor

 

[Cloudschatze]

So... say I happen to have a RLX/B with DOS 5 and the "new" aka incompatible joystick ports... would you happen to know where I could get adapters to my regular Tandy joysticks? I suppose I could make adapters, but I was hoping for a finished look.

I wish I knew. I'm in the same situation, having recently "upgraded" from an RLX-HD/A to an RLX-HD/B (Faster video chipset in the latter.) The current plan is to remove the full-size DIN connectors from two joysticks, and attach mini-DIN connectors in their stead.

My biggest gripe with my RLX is its VGA font... I think it's horribly ugly.

Hmm. I like the font.

 

[Raven]

I don't have joysticks for my Tandy, either of you have spares? My RL/HD has the standard 5-pin-din ports..