"PiTubeDirect" Pi co-processor system for BBCmicro (at FB)

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PiyoTaro
Posts: 169
Joined: Thu Jun 01, 2017 11:13 am

Re: Had no trouble reading the specnext group

Post by PiyoTaro » Mon Mar 11, 2019 8:08 am

SpectrumOldi wrote:
Thu Mar 07, 2019 7:51 am
on Facebook even though I am not on Facebook. These days it has become impossible. It switches between the Facebook page and the "Not Logged In. Please log in to continue" window all the time, very fast. I've tested it on several browsers and even on other computers with different IP numbers. Same result.

This was also the same with the facebook ZXSpectrumNextGaming group for a period, but can now be read as usual.
On February 23rd weekend, when trying to display a publicgroup on FaceBook, "Please log in" does not disappear and the browser reloaded the screen many times. When coming to see the publicgroup at night, the browser caused behavior to refuse to display.
On March 8th last weekend, I was able to go back to the FB publicgroup log.

P.S.
Since it seems that the article of "co-processor" to which David Ball was posted on February 26th (during this period) is not interested, so I would like to repost this post.
https://www.facebook.com/groups/specnex ... %22O%22%7D
*Contents: An introduction article of "PiTubeDirect" Pi second processor project on GitHub. Author hoglet67. https://github.com/hoglet67/PiTubeDirect/wiki
(**Addition 2019/3/24: The CPU of "BBCmicro" is 6502. It is possible to change to another processor by "Tube bus". https://en.wikipedia.org/wiki/BBC_Micro#Description )

ZXSpectrum's extended function board also has a method of attaching it to "CPU socket" instead of inserting it into "edge connector". (When you search the sound board on ebay ...)
Last edited by PiyoTaro on Sun Mar 24, 2019 12:12 pm, edited 1 time in total.

PiyoTaro
Posts: 169
Joined: Thu Jun 01, 2017 11:13 am

"PiTubeDirect" Pi co-processor system for BBCmicro (at FB)

Post by PiyoTaro » Sun Mar 24, 2019 12:23 pm

(On February 23rd weekend, when trying to display a publicgroup on FaceBook...)
Since it seems that the article of "co-processor" to which David Ball was posted on February 26th (during this period) is not interested, so I would like to repost this post.
David Ball
2月26日 13:53
https://www.facebook.com/groups/specnex ... 704497918/

Has anyone else seen the RetroClinic boards that uses a Raspberry Pi Zero inside a BBC master as a set of selectible co-processors?
6502 running at either the original 3MHz, or up to a blistering equivalent of 274MHz
A Z80, running at 60Mhz for CP/M
An 80286 for DOS
A 32016 Cambridge Co-Processor for running the Panos Operating System.
A 6809
A 9MHz emulation of the original ARM Evaluation system
A native ARM Co-Processor, running at 700 MHz
This sounds like something that could be used usefully inside the ZXNext...
*Contents: An introduction article of "PiTubeDirect" Pi second processor project on GitHub. Author hoglet67. https://github.com/hoglet67/PiTubeDirect/wiki
(**Addition 2019/3/24: The CPU of "BBCmicro" is 6502. It is possible to change to another processor by "Tube" interface. https://en.wikipedia.org/wiki/BBC_Micro#Description )

Note that ZXSpectrum compatible machines use "CPU socket" instead of "edge connector" as a system extension method such as DMA and AY. It seems that I wanted to write this.

DarkTrancer
Posts: 2
Joined: Mon Jul 10, 2017 9:08 am

Re: "PiTubeDirect" Pi co-processor system for BBCmicro (at FB)

Post by DarkTrancer » Sun Mar 31, 2019 7:05 pm

I'm confused, are you saying why arn't we talking about BBC masters,6502 and raspberry pi zero on a Zx Spectrum Next group and because the post got no traction you must spam it on a Zx Spectrum Next forum?
813

Alcoholics Anonymous
Posts: 489
Joined: Mon May 29, 2017 7:00 pm

Re: "PiTubeDirect" Pi co-processor system for BBCmicro (at FB)

Post by Alcoholics Anonymous » Sun Mar 31, 2019 8:26 pm

No I think he's suggesting making the interface to the pi similar to the bbc's pitube interface to the pi.

I don't think that makes any sense on a next - emulating other 8-bit processors on the pi doesn't really add anything but it does manage to slow down a 1GHz arm cpu a great deal. On a bbc it does make sense because it had a tube specifically to plug in other processors from the beginning and this is just extending that idea to the modern day by emulating these processors at high speed.

For the actual interface between the native 6502 end and the arm, maybe there's something that can be learned. But I am under the impression it's done through a 2MHz pipe that exchanges messages so it's a bit on the slow side and depends on running metal code at the pi end that is constantly monitoring the 6502 bus.

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varmfskii
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Location: Albuquerque, NM USA

Re: "PiTubeDirect" Pi co-processor system for BBCmicro (at FB)

Post by varmfskii » Sun Mar 31, 2019 10:50 pm

Having looked into the functioning of the tube interface on the BBC Micro, I can tell you that you have a set of (memory mapped) I/O ports that allow communication between the BBC Micro and the CPU on the tube. Basically you are right, you pass code through the interface to be written into memory local to the tube CPU, the tube CPU then executes this code and sends results back to the the BBC Micro. This looks like simply running the code on the tube's CPU because of the I/O hooks in the BBC Micro's ROMs (OS).
Backer #2741 - TS2068, Byte, ZX Evolution

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