07 February 2019, 19:15 | #1 |
Registered User
Join Date: Apr 2009
Location: N/A
Posts: 962
|
Accelerator card in A500 bottom expansion slot?
I have always been under the impression that the bottom expansion port was there only to provide the A500+ with an extra 1MB of ChipRAM, and the case of the A500, with an extra 512KB of SlowRAM and Battery.
However today I came across this: http://amiga.resource.cx/exp/powerpc From what I can understand this takes control from the motherboard 68K processor to its own NEC V30 processor to emulate a PC on the amiga. This sounds similar to the accelerator boards of the A1200 where the processor on the accelerator board takes over control from the 020 on the motherboard. So I was wondering; does the design of the A500 and A500+ allow for-example an 020 or 030 accelerator card to be installed in the bottom expansion port? If yes how come (to my knowledge) no 68K accelerator was designed in this fashion? Last edited by Sim085; 07 February 2019 at 20:14. |
07 February 2019, 22:32 | #2 |
Registered User
Join Date: Jun 2014
Location: milan / italy
Posts: 174
|
The website is wrong. It adds chip/slow RAM not fast RAM. Indeed, all the ads don't say it is fast RAM.
I think it works by having both the 68k and x86 running in parallel. The RAM is shared and used to exchange data and commands. On the Amiga side runs software that serves request from the x86 side interfacing with the keyboard, serial, HDD, etc. The Amiga emulates the EGA/CGA and sound cards too. The RAM disk is because the original a500 (Agnus really) cannot address more than 0.5mb of slow RAM. The Amiga fast RAM can be seen by the x86 because EMS is a bank switching system. I imagine the driver just copies the data back and forward when the BIOS wants to switch bank. |
07 February 2019, 23:08 | #3 | |
Registered User
Join Date: Apr 2018
Location: Stockholm / Sweden
Posts: 129
|
Quote:
If you're interested you can have a look at the schematics, https://www.amigawiki.org/dnl/schematics/A500_R6.pdf, page 4 (sheet 3), to see what signals are connected to the trapdoor expansion slot. |
|
08 February 2019, 15:37 | #4 | |
Registered User
Join Date: Apr 2009
Location: N/A
Posts: 962
|
That really looks like a great project. Does this project (A314?) have its own page? I have gone through the linked thread.
How is this planned to be used? the onboard processor offloads instructions to the co-procesor (in this case the raspberry pi) through the shared memory and then collect the execution results? Or a way to share the raspberry pi resources (ex: network interface) with the amiga? Quote:
|
|
10 February 2019, 17:02 | #5 | ||
Registered User
Join Date: Apr 2018
Location: Stockholm / Sweden
Posts: 129
|
I'm afraid there's no web page for it yet; it's on the to do-list.
Quote:
For example, the file system a314fs works as follows: a program on the Raspberry (a314fsd) registers a service with a certain name ("a314fs"). The file system is implemented on the Amiga side as a file system handler (L:a314fs) which immediately connects to the "a314fs" service and thus establishes a logical channel. After that, the Amiga side forwards each file system operation (list files, read file, etc) to the Raspberry through that logical channel, the Raspberry performs the file operation on its local file system, and then sends a packet back with the result of the operation. Quote:
|
||
18 April 2019, 12:43 | #6 |
Happy Registered User
Join Date: Apr 2009
Location: Stockholm, Sweden
Posts: 101
|
Sneak preview
A few boards have been made in their latest iteration, beta-2. They work perfectly, hours on end. We have identified one (!) issue where the board wasn't working properly, and that was the combination R5 motherboard - 8371 Agnus - HC508 turbo @ 50 MHz. Change any of those parametrs, and it works just fine
And here's the hardware p0rn you've been waiting for: |
18 April 2019, 13:23 | #7 |
Bit Copying Bard
Join Date: Jan 2017
Location: Kelty, Fife, Scotland
Age: 41
Posts: 1,293
|
Excellent work
|
18 April 2019, 13:31 | #8 |
Registerdeaded abUser
Join Date: Sep 2013
Location: Beyond the Wall
Age: 46
Posts: 114
|
Can't wait to get one!
|
18 April 2019, 14:22 | #9 |
Registered User
Join Date: Oct 2017
Location: Germany
Posts: 193
|
I'm really excited to see more on the A314. Keep up the great work.
|
19 April 2019, 18:45 | #10 |
Registered User
Join Date: Sep 2018
Location: Nottingham
Posts: 340
|
Awesome project....I want one too lol
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
Thread Tools | |
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Kipper2k's 8MB+IDE: make a slot for the CF card in A500? | Photon | Hardware mods | 5 | 06 May 2019 20:30 |
Accelerator Card For A500? Can Anyone Help? | nathanm1991 | MarketPlace | 5 | 29 April 2018 17:05 |
Wanted:A500 Accelerator Card :-) | nathanm1991 | MarketPlace | 0 | 29 April 2018 00:59 |
Can I use an A2000 Accelerator Card in an A500? | Sim085 | support.Hardware | 7 | 03 August 2013 14:46 |
CD32 expansion slot to A1200 possible? | Akiko | support.Hardware | 2 | 18 November 2011 18:15 |
|
|