PCjr Accelerator

Hardware questions and modifications
Tempest
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PCjr Accelerator

Post by Tempest »

Did anyone see this? He's claiming that the PCjr can reach AT speeds with his plug in accelerator and a command line program. Seems too good to be true.

https://your.cheer.id/ibm-pcjr-fpga-acc ... r-mcl86jr/
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Brutman
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Re: PCjr Accelerator

Post by Brutman »

Old news ;-)

You can find the original discussion of it right here on this forum: viewtopic.php?f=1&t=603&p=4489

(Ted is an engineer at one of the bigger Tech firms.)
Tempest
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Re: PCjr Accelerator

Post by Tempest »

I see that now. Did anything every become of this? The last post is from 2017.
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DoctorOctal
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Re: PCjr Accelerator

Post by DoctorOctal »

The link you posted above is to an illegitimate, mangled copy of Ted’s original blog entry that describes what he’s done:

<https://microcorelabs.wordpress.com/2020/11/12/ibm-pcjr-accelerator-mcl86jr/>

You can backtrack to earlier entries for more of the story.

He ended up designing a plug-in board with RAM as discussed in the thread on this forum. He made a few copies, and I have one.

I’ve done some preliminary testing, and it mostly seems to work well. Benchmarks show AT-like speed and applications run noticeably faster. I’ve run into some compatibility issues, however, that aren’t just because of the speed difference. For example, even in cycle-accurate mode, some benchmarks lock up the machine, and the built-in diagnostics are very weirdly screwed up. I think there may be some bugs to work out but haven’t yet had a chance to finish my testing and follow up with Ted.
Tempest
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Re: PCjr Accelerator

Post by Tempest »

Ok, thanks for the info. I await the day my PCjr can run some of those later games that support Tandy graphics at a normal speed.
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GHiero
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Re: PCjr Accelerator

Post by GHiero »

Tempest wrote:Ok, thanks for the info. I await the day my PCjr can run some of those later games that support Tandy graphics at a normal speed.
With a PC Sprint Mod your PCjr. can run games faster than many Tandys.
Tempest
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Re: PCjr Accelerator

Post by Tempest »

GHiero wrote:
Tempest wrote:Ok, thanks for the info. I await the day my PCjr can run some of those later games that support Tandy graphics at a normal speed.
With a PC Sprint Mod your PCjr. can run games faster than many Tandys.
Too fast isn't a good thing for compatibility. Got a link to this mod? PC Sprint Mod is a bit too generic for Google to figure out.
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GHiero
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Re: PCjr Accelerator

Post by GHiero »

Tempest wrote:
GHiero wrote:
Tempest wrote:Ok, thanks for the info. I await the day my PCjr can run some of those later games that support Tandy graphics at a normal speed.
With a PC Sprint Mod your PCjr. can run games faster than many Tandys.
Too fast isn't a good thing for compatibility. Got a link to this mod? PC Sprint Mod is a bit too generic for Google to figure out.
You cast your line too far, your fish are much closer to shore : viewtopic.php?f=1&t=763
Tempest
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Re: PCjr Accelerator

Post by Tempest »

GHiero wrote: You cast your line too far, your fish are much closer to shore : viewtopic.php?f=1&t=763
Ah, thank you. Are these boards still being made?
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RiverBoa99
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Re: PCjr Accelerator

Post by RiverBoa99 »

He may make some more in the future. I'll let you know what I hear from him.
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