| New board : 68360 VME processor [message #7700] |
Mon, 25 May 2020 00:47  |
trianon
Messages: 20
Registered: May 2020
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Junior Member |
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Hi all,
I'm new (posting, not admiring) onto this forum and would like to share my 68k project with all of you and hoping to also learn something.
The idea, during the last 30 years I have accumulated a lot of 68k stuff that I want use now on a board design :
- The only purpose of the design will be to have FUN.
- Kiss (keep it simple), for a first design no difficult DRAM controller, no 6 layer full SMD board...
- Use old THT parts from the '90, a smd cap or resistor is possible if it helps on EMC but no FPGA, BGA.
- Connect to the VME bus, I do have a 20 slot backplane for 160x100 boards (no 100% needed).
- Multi processor setup, yesss just for the fun I want 4 cpu's running together.
- High speed serial inter-processor communication, A bit like the old transputer.
How, what, when, who ....
- PCB design in Kicad on an 2 or 4 layer board 160x100.
- 68360RC25 processor (I do have 5 pcs PGA version with the sockets ;)
- 4 x 512k SRAM in DIP32 sockets (also on stock)
- boot from 32k EEPROM in DIP28 (it's the only NV memory I have) ANY SUGGESTIONS ?
- Use BDM to program bootcode in the the EERPOM (I have made a basic BDM interface with an Arduino)
- 68882RC co-processor, if feasible only, because I have them on stock.
- TTL debug port, will connect FTDI USB-TTL cable externally.
- One serial ports of the QUICC with RS422 level onto a RJ45 connector (high speed in the 90).
- VME interface with 74F245 buffers and one Altera EPM7064S CPLD as controller.
Will also build a debug card
* A main controller for the VME (slot 1 functions) will be wire wrap board with bigger CPLD.
* add LCD + IDE HD + FTDI USB IO board on it.
Questions, shout out for help :
? I don't know how I should connect the 68882 to the 68360 yet, peripheral mode yes, but pins ?
? I don't have any 68360 compatible monitor program yet ?
? I don't have a 68k assembler nor C compiler yet (using 68332 BCC CPU32Bug now to code) ?
? and a lot of questions that will follow once I start the design ...
Any suggestions or remarks are welcome...
Best regards,
Steve
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| Re: New board : 68360 VME processor [message #7707 is a reply to message #7700] |
Tue, 26 May 2020 09:12  |
coredump
Messages: 33
Registered: January 2020
Location: Germany
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Member |
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Hi Steve,
this indeed sounds like You will have a couple of fun.
A few unordered comments:
trianon wrote on Mon, 25 May 2020 09:47
? I don't know how I should connect the 68882 to the 68360 yet, peripheral mode yes, but pins ?
https://www.nxp.com/docs/en/data-sheet/BR509.pdf
Page 12 ff. discusses it in detail.
The 32-Bit connection seems to fit the '360 fine, doesn't it?
Quote:
? I don't have any 68360 compatible monitor program yet ?
? I don't have a 68k assembler nor C compiler yet (using 68332 BCC CPU32Bug now to code) ?
To make the ball rolling You could use GNU-Tools.
At least 20 years ago it was no problem to use them even under Windows (Cygwin) as a cross compiler.
But I consider it more fun to have the development tools running on the target.
Maybe a simple female header for an IDE port locally on the board? Just for the first time till Your separate IDE-Board is functional.
Having a serial debug port and a CompactFlash card You are able to run CP/M 68K. That would bring an assembler (linker etc.) (68000/68010 only), a K&R C-compiler and the microemacs editor on the board.
CP/M 68K is simpleminded and quite restricted, but it is simple to port it.
Quote:
- Kiss (keep it simple), for a first design no difficult DRAM controller, no 6 layer full SMD board...
There is a DRAM Controller in the '360. You have already payed for it ;-)
It does not even require an external address multiplexer if you make it accessible locally only, just the 72p. SIMM socket and the connections. 8MB RAM or more almost for free...
Quote:
- boot from 32k EEPROM in DIP28 (it's the only NV memory I have) ANY SUGGESTIONS ?
Some EEPROMS (like 28F256) require 12V to program them in situ. If Yours is of this sort You may want to use a 5V-only FLASH like 29F256.
Or, if 32pin DIP is ok, larger ones like the 29F004 (512KB). Better too much than too litte...
Have fun and keep us informed of the progress, please :-)
Best regards
Detlef
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| Re: New board : 68360 VME processor [message #7711 is a reply to message #7707] |
Wed, 27 May 2020 04:20 |
trianon
Messages: 20
Registered: May 2020
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Junior Member |
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Thanks for your response Detlef,
For the 68882 I was thinking to go for the 8 bits databus only for an easier layout but then you need to connect D0 to D8 + D16 + D24, D1 to D9....
And this seems to be very hard to do on a 2/4 layer board, so yes 32 bits would be the way to go ... if I do find the space on the board.
About DRAM, I know it's an easy/cheap way to get a large amount of RAM to run an full OS, but I don't have any of these parts (sockets, DRAM modules).
The SRAM I already have, and an option in the future would be to build a small DIP32 to SMD adapter board for FAST TERMINATION speed (have the parts also).
The 32k EERPOM I have is not of the Flash version, but the old single byte write version, only 5V needed, but very slow also. Could work as boot only device ?
Now I'a very interested in maybe having some OS (low end) running on the boards, I heard already about OS9 and heard of CP/M from the C128 days.
But where can you find these OS, are they free and I suppose you have to adapt them to your HW and compile, or is it all to do with drivers ?
Current state is learning KiCad (installed it on Saturday), fingering out how to interface to the VME bus and fining a way to route is all.
Best Regards,
Steve
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| Re: New board : 68360 VME processor [message #7716 is a reply to message #7715] |
Wed, 27 May 2020 13:15 |
trianon
Messages: 20
Registered: May 2020
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Junior Member |
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Hi Roger,
Can you maybe point me where to start with CP/M 68K (Hackaday,... ?
Maybe strange for an Amiga guy, but I only use/know Windows, but then I was developing windows CE devices the last 15 years.
I'm really impressed by KiCad, but I will route all traces by hand ;)
Hi Bo,
I do also have the EPM7128S, but it's a bigger PLCC84 instead of a PLCC44 and will be difficult to get it all on the eurocard.
There is also good news, the 68360 already has a SPI interface.
BDM, I build it with an Arduino board and some wires. Interface is by serial port over USB and commands similar like the CPU32debug.
Works fine on the 68332 BCC develop board. I will write a small Phyton program so I can flash a hex file by BDM to RAM or FLASH.
Maybe not the fasted BDM, but it will work on different platforms.
About 10 years ago I downloaded a lot of 68k code from the Motorola website (where just switching to Freescale), will have
a look if as32 is part of it.
Br,
Steve
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| Re: New board : 68360 VME processor [message #7727 is a reply to message #7725] |
Thu, 28 May 2020 14:56 |
mikemac
Messages: 250
Registered: March 2017
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Senior Member |
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quarterturn wrote on Thu, 28 May 2020 12:11Any chance to target running a linux kernel?
If he sticks to 2MB of on board SRAM, then it's not likely.
If he puts a couple SIMM slots on his processor board, then probably. This would make it very similar to the KISS68030 board.
If he expects to use extended RAM over the VME bus, maybe but it'll be tight. A single connector VME board is limited to 24 address lines/16 data lines. You have to do a card with both connectors on it for a full 32b data bus and a full 32b address space.
When I looked, VME cards were expensive, even used on Ebay, as they're aimed at the commercial market. If the design will be relying on VME add-on cards for things like RAM, disk controllers, network interfaces, etc, the system will get too expensive for my tastes. The extra large boards and the expense of add-ons were the reasons I stopped looking at VME for my dream 68K system. But that's just my own trade offs. This is his board so he can and should do what he wants.
Mike
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| Re: New board : 68360 VME processor [message #7728 is a reply to message #7725] |
Thu, 28 May 2020 23:26 |
trianon
Messages: 20
Registered: May 2020
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Junior Member |
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Hi,
No there are no plans to use linux kernel as there is no MMU inside the 68360, and the low memory available.
What is the minimal size needed for linux, 32 or 64 mB ? But you do need the MMU for it to run ?
My only knowledge of linux like OS is from 20 years ago on Sun and SGI machines, ls, grep, and that's about it  .
Now looking at storage, I have some old IDE drives (3.5 and 2.5 inch), the 2.5 inch has the advantage
of only needing 5V and I can replace it by an CF card on the adapter PCB.
But when I look at the pinout of an IDE compared to the CF card, the first one is much more complicated.
- What is the best best option if I want to use it maybe on CMP/M 68k ?
- Do I put it on the databus (with some buffers) or by a IO port (68360 has enough free).
Br,
Steve
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| Re: New board : 68360 VME processor [message #8460 is a reply to message #8456] |
Mon, 12 April 2021 09:20 |
mikemac
Messages: 250
Registered: March 2017
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Senior Member |
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trianon wrote on Sun, 11 April 2021 10:31
Second to that I have my BDM debugger project (build with only an Arduino UNO) working 100% on the MOT 68332evs develop kit.
I can stop the CPU, r/w any register and memory. It will be the perfect help to debug the 68360 design as I don't have
any debugger for it yet. Will also need it to program my EEPROM or FLASH boot device.
I'd love to hear more details about your BDM debugger project! I've seen the connector on several 68K reference designs but that's all I know about it.
Mike
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| Re: New board : 68360 VME processor [message #8728 is a reply to message #7725] |
Tue, 29 June 2021 05:39 |
marcopolo
Messages: 21
Registered: November 2020
Location: Nancy (FRANCE)
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Junior Member |
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quarterturn wrote on Thu, 28 May 2020 12:11Any chance to target running a linux kernel?
Microware OS-9 would be a better choice.
Everything runs on Linux these days, so what's the point of releasing a new Linux board?
Marc
My Archives (68K, Old logic, SSB radio): marc.retronik.fr
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| Re: New board : 68360 VME processor [message #8768 is a reply to message #8730] |
Mon, 05 July 2021 16:11 |
etchedpixels
Messages: 333
Registered: October 2015
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Senior Member |
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For debugging if you can write a simple polled serial driver and some small functions then you can use GDB, and the tools stacked on top of it.
The old CPU32 package even has a reference implementation to put it on SMC1.
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