English Amiga Board Amiga Lore


Go Back   English Amiga Board > Support > support.Hardware > Hardware mods

 
 
Thread Tools
Old 08 March 2014, 23:02   #61
Kai
Registered User
 
Join Date: Apr 2011
Location: Brighton, UK
Age: 35
Posts: 54
Yeah Geoff has soldered CPLD's and FPGA's using that method, works well enough for him

He's finding this all very interesting, according to the last message i got!
Kai is offline  
AdSense AdSense  
Old 09 March 2014, 02:12   #62
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,514
PGA almost always require via's where for QFP there is chance to reduce number of via's.
PGA also require socket (in theory can be soldered directly but... it is smart to use socket).
pandy71 is offline  
Old 11 March 2014, 03:41   #63
Kai
Registered User
 
Join Date: Apr 2011
Location: Brighton, UK
Age: 35
Posts: 54
....and i just found a way to implement 68030 cache....can someone check this over as well to make sure i'm not jumping the gun?

http://www.nextcomputers.org/NeXTfil...che_Design.pdf

The Cache Comparators are long since discontinued but...i have a source, and there are more than a few!

http://www.4starelectronics.com/part...T216320FM.html

Asking around suppliers for the MC68030FE25 - anyone know the difference, if any, between the -B and -C models? Just revisions?

Last edited by Kai; 12 March 2014 at 03:13.
Kai is offline  
Old 12 March 2014, 22:07   #64
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,514
Quote:
Originally Posted by Kai View Post
....and i just found a way to implement 68030 cache....can someone check this over as well to make sure i'm not jumping the gun?

http://www.nextcomputers.org/NeXTfil...che_Design.pdf

The Cache Comparators are long since discontinued but...i have a source, and there are more than a few!

http://www.4starelectronics.com/part...T216320FM.html

Asking around suppliers for the MC68030FE25 - anyone know the difference, if any, between the -B and -C models? Just revisions?
Kai, no sense to search for this particular device - probably any TAG SRAM from PC can be used - probably there is some change in code required but anyway PAL's should be replaced by one CPLD, also probably some memory (32 bit, modern SDRAM or at least FPM/EDO) should be added so in total CPU + CACHE + MEMORY.
Probably large part of Amiga memory map must have cache excluded thus i would rather focus on very fast normal memory - today perhaps even single cycle up to 50MHz (assuming 100 - 133MHz clock +2.5 cycle latency from average SDRAM).

Also TI offer BCT version for such TAG SRAM.
pandy71 is offline  
Old 13 March 2014, 00:46   #65
Kai
Registered User
 
Join Date: Apr 2011
Location: Brighton, UK
Age: 35
Posts: 54
Yeah again - PAL -> CPLD is easy enough, but i was concerned that deviating too far from the design would be problematic.

Cache excluded? I dunno why, maybe my x86-centric view, but no cache seems...wrong How much memory you reckon would be a fair amount to add? 8MB?

Found a supplier of those CQFP '030s though - $14.50 each, reasonable enough price, so i ordered 4 of them for testing.

Apologies for the scattergun approach - trying to shoehorn as much in as i can, and of course you guys are better at this than me
Kai is offline  
Old 13 March 2014, 01:17   #66
Photon
Moderator
Photon's Avatar
 
Join Date: Nov 2004
Location: Hult / Sweden
Posts: 4,307
Internal 030 or 040 for "the real three" OCS Amigas?
Photon is offline  
Old 13 March 2014, 17:00   #67
Zetr0
Ya' like it Retr0?
Zetr0's Avatar
 
Join Date: Jul 2005
Location: United Kingdom
Age: 42
Posts: 9,769
I love this thread.

If I could offer anything, I would suggest attempting to develop a like for like (or close as possible) adaptor to the original LUCAS and work the bugs out from that.

Once you have this you can implement this into one fat XC9572 CPLD - it should also be enough to handle / arbitrate 8MB of SRAM as well.

I will say that jumping to a combined CPLD as an initial implementation may be too big a step to de-bug as efficiently, or perhaps I should say quickly as internal speeds of the CPLD may introduce problems not foreseen or planned for in the original design.

As others have suggested SMT/SMD is the way to go, with 4 layers and good decoupling you should be able to achieve a 20Mhz 020 quite comfortably. Unfortunately PGA based 020's are difficult to source in any reasonable quantity without massive investment, an entry level accelerator based on a TQFP 020 with 8MB SRAM should be a lot cheaper - atleast in component cost.
Zetr0 is offline  
Old 13 March 2014, 21:21   #68
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,514
Cache design like this for Atari ST http://atari4ever.free.fr/hardware/zip/mach16.zip can be translated to Amiga but in Amiga some areas should be excluded from caching.

Not sure about RAM size - 8MB can be DRAM can be SRAM (nowadays no problem 1 - 8 IC's) but... perhaps 64MB? (part can be used as Kick, part as ram disk perhaps recoverable?).

Personally i have few old MC68020/68881 PC ISA AT cards and for me PGA is natural choice (also i have few 68040 in Mac Quadra computers thus perhaps i can go to A500 with 68040 board but i have idea to rebuild Amiga and hide CHIP memory limitations from CPU but this is the point where perhaps FPGA Amiga recreations is simple better).
4 layers is today not so expensive but for sure it need to be ordered from specialized company - opposite to this 2 layer bard can be made in home even by printing directly ink on PCB.

All this lead me to Majsta project - FPGA accelerator with memory controller - probably cheapest and most perspective... but still simple A500 accelerator can have own users...
but once again - clockport, simple Ethernet, perhaps USB, IDE ... lot of things that can be nice... tough choice especially with limited time and resources... all this is pure hobby as similar to Majsta i have no will to do anything for Amiga commercially...
pandy71 is offline  
Old 16 March 2014, 03:34   #69
Kai
Registered User
 
Join Date: Apr 2011
Location: Brighton, UK
Age: 35
Posts: 54
Supply of 68030's in CQFP isn't a problem - can order upto 1200 of the damn things from a single supplier if i ever win the lottery, but i'm happy with the $14 per piece cost as it stands.

Once my friend Geoff has sorted out the PAL -> CPLD, it shouldn't be too hard to include the rest. Zetr0 - the equations are dirt simple, as is the code - having looked at it in a bit more detail, i don't think it's too much of a problem. CPLD's are easier to reprogram, and save on board space. I know, know, i was insistent on PAL's to make it as easy as possible, but if we're going all out on this, why not go as pro as possible?

I'm set on including 8mb of SRAM now - it's just a question of if a cache would be beneficial.

Oh, and a clockport is something that should be easy enough to incorporate. Any more chips than that though, and i might as well make a whole new motherboard

The fewer chips on the board, the better. How about an initial 4 boards, in 2-layer, if possible, ready to plug and play, see if they're all okay?
Kai is offline  
Old 16 March 2014, 18:28   #70
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,514
8MB SRAM will be quite expensive - not sure but perhaps DRAM will be better - curious about SDRAM.
pandy71 is offline  
Old 17 March 2014, 03:15   #71
Licentia
 
Posts: n/a
Do you any eagle files for LUCAS?
 
Old 18 March 2014, 05:30   #72
Kai
Registered User
 
Join Date: Apr 2011
Location: Brighton, UK
Age: 35
Posts: 54
4MB of SRAM isn't too bad - put 2 spots on the PCB for it, or just the one?

http://uk.mouser.com/ProductDetail/C...OAdAOAiDpjs%3d

The slightly slower stuff is even cheaper:

http://uk.mouser.com/ProductDetail/C...u%2fAROoFD8%3d

My vote would be for the 45ns stuff, purely on a price standpoint.
Kai is offline  
Old 18 March 2014, 13:16   #73
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,514
Quote:
Originally Posted by Kai View Post
4MB of SRAM isn't too bad - put 2 spots on the PCB for it, or just the one?
My vote would be for the 45ns stuff, purely on a price standpoint.
for 45ns means no "zero wait states" design i assume... (need to check 030/040 access time)

we need to have 32 bit data bus thus 2 or 4 memory IC's on board (8/16 bit organization) for 4 MB and twice for 8MB (in total up to 8 TSOP48/54).

Going for CPLD perhaps SDRAM controller sound more reasonable...

(this is how such things going, investigating one function you just realize then perhaps you need something more and project at the end is or very big or not exist at all)
pandy71 is offline  
Old 19 March 2014, 17:37   #74
Zetr0
Ya' like it Retr0?
Zetr0's Avatar
 
Join Date: Jul 2005
Location: United Kingdom
Age: 42
Posts: 9,769
@pandy71

If I am not mistaken, with 45ns (90ns round trip) there shouldn't be any wait states on a <33Mhz 030/020
Zetr0 is offline  
Old 19 March 2014, 17:40   #75
kipper2k
Registered User

 
Join Date: Sep 2006
Location: Thunder Bay, Canada
Posts: 3,301
One question i have, is this going to be a group thing or a one off build and if a group thing, do you have the connector (if going to create for the a1200). Ok, i lied, it was 2 questions
kipper2k is offline  
Old 19 March 2014, 18:01   #76
Zetr0
Ya' like it Retr0?
Zetr0's Avatar
 
Join Date: Jul 2005
Location: United Kingdom
Age: 42
Posts: 9,769
@Kips

In regards to Amiga compatibility, as long as /OVR and /INT can either be sourced or synthesised this adapter would work for both the A500 / A600 / A1000 and A2000. While it would be nice to see another accelerator realized for the A1200, its pretty well catered for to be honest, arguably so is the A600 at present.

I suppose as always it comes down to expected target price and how that competes with the existing market.

Personally I would enjoy seeing more A500 love alongside some competing products for the A600.... but what I would really love to be realized is an A2000 accelerator that can have up to 128MB RAM, 030 with MMU, 2x IDE and 4MB Video - however thats a bit of a dream at the moment
Zetr0 is offline  
Old 19 March 2014, 18:17   #77
kipper2k
Registered User

 
Join Date: Sep 2006
Location: Thunder Bay, Canada
Posts: 3,301
The A2000 hasn't seen all that much attention even though it has all the expansion risers that can be tapped, i guess it isn't mainstream enough. Now i have an A2000 i wouldn't mind some "lovin" for it
kipper2k is offline  
Old 19 March 2014, 19:04   #78
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,514
Quote:
Originally Posted by Zetr0 View Post
@pandy71

If I am not mistaken, with 45ns (90ns round trip) there shouldn't be any wait states on a <33Mhz 030/020
Yep, but this is Amiga - look how many people overclock even MC68000...
I see sometimes weird clocks reported - for sure most of people after first shot will try to gain some MHz... And my lousy calculations shows that 8MB SRAM can cost around 80 - 90E...
pandy71 is offline  
Old 19 March 2014, 19:19   #79
kipper2k
Registered User

 
Join Date: Sep 2006
Location: Thunder Bay, Canada
Posts: 3,301
Quote:
Originally Posted by pandy71 View Post
Yep, but this is Amiga - look how many people overclock even MC68000...
I see sometimes weird clocks reported - for sure most of people after first shot will try to gain some MHz... And my lousy calculations shows that 8MB SRAM can cost around 80 - 90E...
Give me the chip info and i will see what i can get them for.
kipper2k is offline  
Old 19 March 2014, 21:08   #80
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL
Posts: 1,514
Quote:
Originally Posted by kipper2k View Post
Give me the chip info and i will see what i can get them for.
http://nl.mouser.com/Semiconductors/...z0y16yZ1z0xtrt

But in fact any asynchronous SRAM 2Mx8 with access time less than 30ns should be fine - i assume BGA is not desired.
pandy71 is offline  
AdSense AdSense  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Clearing out a lot of stuff, A4000T & Zorro Boards, BPPC&Bvision , A1000 etc fitzsteve MarketPlace 3 29 January 2013 00:03
aminet & amiga Plus cds - floppy & cd software/games - hardware & magazines for SALE! bastibs MarketPlace 1 07 May 2008 11:33
Minimig PCB & Power Computing A500 1.5mb ram expansion for sale. Paul_s MarketPlace 2 11 March 2008 20:55
A4K towers & expansion boards - Eagle vs Miconiks. Opinion wanted. alewis support.Hardware 13 15 August 2006 23:31

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 10:01.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Page generated in 0.22255 seconds with 13 queries